Document And Entity Information - shares	6 Months Ended
Document And Entity Information - shares	Sep. 30, 2019	Nov. 01, 2019
Document Information [Line Items]
Entity Registrant Name	AMERICAN SUPERCONDUCTOR CORP /DE/
Entity Central Index Key	0000880807
Trading Symbol	amsc
Current Fiscal Year End Date	--03-31
Entity Filer Category	Accelerated Filer
Entity Current Reporting Status	Yes
Entity Emerging Growth Company	false
Entity Small Business	true
Entity Common Stock, Shares Outstanding (in shares)		21,765,463
Entity Shell Company	false
Document Type	10-Q
Document Period End Date	Sep. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Amendment Flag	false
Title of 12(b) Security	Common Stock ($0.01 par value)

Unaudited Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Sep. 30, 2019	Mar. 31, 2019
Current assets:
Cash and cash equivalents	$ 52,829	$ 77,483
Accounts receivable, net	10,073	7,855
Inventory	15,497	12,119
Note receivable, current portion		2,888
Prepaid expenses and other current assets	5,036	3,053
Total current assets	83,435	103,398
Marketable securities	10,000	0
Property, plant and equipment, net	8,610	8,972
Intangibles, net	2,720	2,890
Right-of-use asset	3,607	0
Goodwill	1,719	1,719
Restricted cash	5,736	715
Deferred tax assets	1,291	1,357
Other assets	325	279
Total assets	117,443	119,330
Current liabilities:
Accounts payable and accrued expenses	18,724	15,885
Lease liability, current portion	424	0
Derivative liabilities	556	4,942
Deferred revenue, current portion	8,345	7,557
Total current liabilities	28,049	28,384
Deferred revenue, long term portion	7,667	7,962
Lease liability, long term portion	3,240	0
Deferred tax liabilities	1,757	1,698
Other liabilities	44	93
Total liabilities	40,757	38,137
Commitments and contingencies (Note 15)
Stockholders' equity:
Common stock	218	216
Additional paid-in capital	1,045,833	1,044,622
Treasury stock	(2,606)	(2,101)
Accumulated other comprehensive loss	(856)	(5)
Accumulated deficit	(965,903)	(961,539)
Total stockholders' equity	76,686	81,193
Total liabilities and stockholders' equity	$ 117,443	$ 119,330

Unaudited Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues	$ 14,012	$ 14,876	$ 27,782	$ 27,483
Cost of revenues	10,248	11,252	22,441	19,966
Gross margin	3,764	3,624	5,341	7,517
Operating expenses:
Research and development	2,398	2,264	4,871	5,103
Selling, general and administrative	5,400	5,175	10,655	10,961
Amortization of acquisition-related intangibles	85	85	170	170
Restructuring	0	93	0	403
(Gain) on Sinovel settlement, net	0	(28,720)	0	(28,720)
Total operating expenses	7,883	(21,103)	15,696	(12,083)
Operating (loss) income	(4,119)	24,727	(10,355)	19,600
Change in fair value of warrants	1,145	282	4,092	(182)
Interest income, net	335	232	840	433
Other income, net	1,520	325	976	934
(Loss) income before income tax expense	(1,119)	25,566	(4,447)	20,785
Income tax (benefit) expense	(294)	3,008	(83)	2,964
Net (loss) income	$ (825)	$ 22,558	$ (4,364)	$ 17,821
Net (loss) income per common share
Basic (in dollars per share)	$ (0.04)	$ 1.11	$ (0.21)	$ 0.88
Diluted (in dollars per share)	$ (0.10)	$ 1.10	$ (0.40)	$ 0.87
Weighted average number of common shares outstanding
Basic (in shares)	20,656	20,313	20,586	20,240
Diluted (in shares)	20,723	20,581	20,736	20,560

Unaudited Condensed Consolidated Statements of Comprehensive (Loss) Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Net (loss) income	$ (825)	$ 22,558	$ (4,364)	$ 17,821
Other comprehensive loss, net of tax:
Cumulative translation adjustment	(1,269)	(678)	(851)	(894)
Total other comprehensive loss, net of tax	(1,269)	(678)	(851)	(894)
Comprehensive (loss) income	$ (2,094)	$ 21,880	$ (5,215)	$ 16,927

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

Unaudited Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	AOCI Attributable to Parent [Member]	Retained Earnings [Member]	Total
Balance (in shares) at Mar. 31, 2018	21,139
Balance at Mar. 31, 2018	$ 211	$ 1,041,113	$ (1,645)	$ 883	$ (988,333)	$ 52,229
Issuance of common stock - ESPP (in shares)	12
Issuance of common stock - ESPP		71				71
Issuance of common stock - restricted shares (in shares)	416
Issuance of common stock - restricted shares	$ 4	(4)
Stock-based compensation expense		1,610				1,610
Issuance of stock for 401(k) match (in shares)	27
Issuance of stock for 401(k) match		172				172
Repurchase of treasury stock			(396)			(396)
Cumulative translation adjustment				(894)		(894)
Cumulative impact of adoption of ASU No. 2014-09					33	33
Net (loss) income					17,821	17,821
Cumulative translation adjustment				(894)		(894)
Balance (in shares) at Sep. 30, 2018	21,594
Balance at Sep. 30, 2018	$ 215	1,042,962	(2,041)	(11)	(970,479)	70,646
Balance (in shares) at Jun. 30, 2018	21,429
Balance at Jun. 30, 2018	$ 214	1,041,980	(1,884)	667	(993,037)	47,940
Issuance of common stock - ESPP (in shares)	12
Issuance of common stock - ESPP		71				71
Issuance of common stock - restricted shares (in shares)	140
Issuance of common stock - restricted shares	$ 1	(1)
Stock-based compensation expense		825				825
Issuance of stock for 401(k) match (in shares)	13
Issuance of stock for 401(k) match		87				87
Repurchase of treasury stock						(157)
Cumulative translation adjustment				(678)		(678)
Net (loss) income					22,558	22,558
Cumulative translation adjustment				(678)		(678)
Balance (in shares) at Sep. 30, 2018	21,594
Balance at Sep. 30, 2018	$ 215	1,042,962	(2,041)	(11)	(970,479)	70,646
Balance (in shares) at Mar. 31, 2019	21,652
Balance at Mar. 31, 2019	$ 216	1,044,622	(2,101)	(5)	(961,539)	81,193
Issuance of common stock - ESPP (in shares)	15
Issuance of common stock - ESPP		100				100
Issuance of common stock - restricted shares (in shares)	184
Issuance of common stock - restricted shares	$ 2	(2)
Stock-based compensation expense		646				646
Issuance of stock for 401(k) match (in shares)	20
Issuance of stock for 401(k) match		173				173
Repurchase of treasury stock			(505)			(505)
Cumulative translation adjustment				(851)		(851)
Net (loss) income					(4,364)	(4,364)
Issuance of common stock - warrant exercise (in shares)	23
Issuance of common stock - warrant exercise		294				294
Cumulative translation adjustment				(851)		(851)
Balance (in shares) at Sep. 30, 2019	21,894
Balance at Sep. 30, 2019	$ 218	1,045,833	(2,606)	(856)	(965,903)	76,686
Balance (in shares) at Jun. 30, 2019	21,857
Balance at Jun. 30, 2019	$ 218	1,045,244	(2,384)	413	(965,078)	78,413
Issuance of common stock - ESPP (in shares)	15
Issuance of common stock - ESPP		100				100
Issuance of common stock - restricted shares (in shares)	10
Issuance of common stock - restricted shares
Stock-based compensation expense		397				397
Issuance of stock for 401(k) match (in shares)	12
Issuance of stock for 401(k) match		92				92
Repurchase of treasury stock			(222)			(222)
Cumulative translation adjustment		(1,269)				(1,269)
Net (loss) income					(825)	(825)
Cumulative translation adjustment		(1,269)				(1,269)
Balance (in shares) at Sep. 30, 2019	21,894
Balance at Sep. 30, 2019	$ 218	$ 1,045,833	$ (2,606)	$ (856)	$ (965,903)	$ 76,686

Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities:
Net (loss) income	$ (4,364)	$ 17,821
Adjustments to reconcile net loss to net cash (used in)/provided by operations:
Depreciation and amortization	2,262	2,307
Stock-based compensation expense	646	1,610
Provision for excess and obsolete inventory	196	514
Fair Value Adjustment of Warrants	(4,092)	182
Non-cash interest income	(112)	(112)
Other non-cash items	(888)	(727)
Changes in operating asset and liability accounts:
Accounts receivable	(2,244)	(279)
Inventory	(3,589)	1,278
Prepaid expenses and other assets	(1,810)	(572)
Accounts payable and accrued expenses	2,799	2,166
Deferred revenue	711	(593)
Net cash (used in)/provided by operating activities	(10,485)	23,595
Cash flows from investing activities:
Purchase of property, plant and equipment	(1,736)	(418)
Proceeds from the sale of property, plant and equipment	3,001	138
Purchase of marketable securities	(10,000)
Change in other assets	66	(131)
Net cash used in investing activities	(8,669)	(411)
Cash flows from financing activities:
Employee taxes paid related to net settlement of equity awards	(505)	(396)
Proceeds from exercise of employee stock options and ESPP	100	71
Net cash used in financing activities	(405)	(325)
Effect of exchange rate changes on cash	(74)	(774)
Net (decrease)/increase in cash, cash equivalents and restricted cash	(19,633)	22,085
Cash, cash equivalents and restricted cash at beginning of period	78,198	34,249
Cash, cash equivalents and restricted cash at end of period	58,565	56,334
Supplemental schedule of cash flow information:
Cash paid for income taxes, net of refunds	130	1,438
Issuance of common stock to settle liabilities	173	172
Hercules [Member]
Supplemental schedule of cash flow information:
Issuance of common stock to Hercules to settle warrant liability	$ 294	$ 0

Note 1 - Nature of the Business and Operations and Liquidity	6 Months Ended
	Sep. 30, 2019
Notes to Financial Statements
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	1. Nature of the Business and Operations and Liquidity Nature of the Business and Operations American Superconductor Corporation (together with its subsidiaries, “AMSC®” or the “Company”) was founded on April 9, 1987. The Company is a leading system provider of megawatt-scale power solutions that enhance the performance of the power grid, protect the Navy’s fleet, and lower the cost of wind power. The Company’s system level products leverage its proprietary “smart materials” and “smart software and controls” to provide enhanced resiliency and improved performance of megawatt-scale power flow. These unaudited condensed consolidated financial statements of the Company have been prepared on a going concern basis in accordance with United States generally accepted accounting principles (“GAAP”) and the Securities and Exchange Commission’s (“SEC”) instructions to Form 10 -Q. The going concern basis of presentation assumes that the Company will continue operations and will be able to realize its assets and discharge its liabilities and commitments in the normal course of business. Certain information and footnote disclosures normally included in the financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to those instructions. The year-end condensed balance sheet data was derived from audited financial statements but does not include all disclosures required by GAAP. The unaudited condensed consolidated financial statements, in the opinion of management, reflect all adjustments (consisting of normal recurring adjustments) necessary for a fair statement of the results for the interim periods ended September 30, 2019 and 2018 and the financial position at September 30, 2019 ; however, these results are not necessarily indicative of results which may be expected for the full year. The interim condensed consolidated financial statements, and notes thereto, should be read in conjunction with the audited consolidated financial statements for the year ended March 31, 2019 , and notes thereto, included in the Company’s annual report on Form 10 -K for the year ended March 31, 2019 filed with the Securities and Exchange Commission on June 5, 2019. Liquidity The Company has historically experienced recurring operating losses and as of September 30, 2019 , the Company had an accumulated deficit of $ 965.9 million. In addition, the Company has historically experienced recurring negative operating cash flows. At September 30, 2019 , the Company had cash, cash equivalents, and marketable securities of $ 62.8 million, with no outstanding debt other than ordinary trade payables. Marketable securities include certificate of deposits with maturities between twelve and twenty-four months. Cash used in operations for the six months ended September 30, 2019 was $ 10.5 million. On July 3, 2018, the Company and its wholly-owned subsidiaries Suzhou AMSC Superconductor Co. Ltd. (“AMSC China”) and AMSC Austria GMBH (“AMSC Austria”) entered into a settlement agreement (the “Settlement Agreement”) with Sinovel Wind Group Co., Ltd. (“Sinovel”). The Settlement Agreement settles the litigation and arbitration proceedings between the Company and Sinovel. Under the terms of the Settlement Agreement, Sinovel agreed to pay AMSC China an aggregate cash amount in Renminbi (“RMB”) equivalent to $57.5 million, consisting of two installments. Sinovel paid the first installment of the RMB equivalent of $32.5 million on July 4, 2018, which was repatriated to the Company during the nine months ended December 31, 2018 and paid the second installment of the RMB equivalent of $25.0 million on December 27, 2018. The Company’s fiscal 2018 results included the net gain received from the settlement with Sinovel of $52.7 million. On February 1, 2018, ASC Devens LLC (the “Seller”), a wholly-owned subsidiary of the Company, entered into a Purchase and Sale Agreement (the “PSA”) with 64 Jackson, LLC (the “Purchaser”) and Stewart Title Guaranty Company (“Escrow Agent”), to effectuate the sale of certain real property located at 64 Jackson Road, Devens, Massachusetts, including the building that had served as the Company’s headquarters (collectively, the “Property”), in exchange for total consideration of $23.0 million, composed of (i) cash consideration of $17.0 million, and (ii) a $6.0 million subordinated secured commercial promissory note payable to the Company (the “Seller Note”). Subsequently, the Seller, the Purchaser and Jackson 64 MGI, LLC (“Assignee”) entered into an Assignment of Purchase and Sale Agreement (the “Assignment Agreement”), pursuant to which the Purchaser assigned all of its rights and interests in the PSA to the Assignee and the Assignee agreed to assume all of the Purchaser’s obligations and liabilities under the PSA. The transaction closed on March 28, 2018, at which time the Company received, from the Assignee, cash consideration, net of certain agreed upon closing costs, of $16.9 million, and the Seller Note at an interest rate of 1.96%. The Seller Note was secured by a subordinated second mortgage on the Property and a subordinated second assignment of leases and rents. The Company received the first $3.0 million payment due pursuant to the Seller Note on March 28, 2019 and the second $3.0 million payment plus interest on May 23, 2019. In December 2015, the Company entered into a set of strategic agreements valued at approximately $210.0 million with Inox Wind Ltd. (“Inox” or “Inox Wind”), which includes a multi-year supply contract pursuant to which the Company will supply electrical control systems ("ECS") to Inox and a license agreement allowing Inox to manufacture a limited number of ECS. After Inox purchases the specified number of ECS required under the terms of the supply contract, Inox agreed that the Company will continue as Inox’s preferred supplier and Inox will be required to purchase from the Company a majority of its ECS requirements for an additional three -year period. Pursuant to these strategic agreements, Inox must forecast future purchase orders of sets of ECS which become firm orders three months prior to shipment, and Inox must post letters of credit before the Company will ship such orders. Inox is currently delinquent on its obligation to post letters of credit for sets of ECS that Inox forecasted to purchase under the terms of the supply contract. We cannot predict if and when Inox will post letters of credit consistent with the forecasted ECS quantities. Inox’s failure to post letters of credit and take delivery of forecasted ECS quantities would impact the Company’s revenues and liquidity. The Company believes that based on the information presented above and its quarterly management assessment, it has sufficient liquidity to fund its operations and capital expenditures for the next twelve months following the issuance of the financial statements for the six months ended September 30, 2019 . The Company’s liquidity is highly dependent on its ability to increase revenues, including its ability to collect revenues under its agreements with Inox, its ability to control its operating costs, and its ability to raise additional capital, if necessary. There can be no assurance that the Company will be able to continue to raise additional capital, on favorable terms or at all, from other sources or execute on any other means of improving liquidity described above.

Note 2 - Revenue Recognition

6 Months Ended

Sep. 30, 2019

Notes to Financial Statements

Revenue from Contract with Customer [Text Block]

Revenue Recognition

April 1, 2018,

the Company adopted Accounting Standards Codification (“ASC”)

606,

Revenue from Contracts with Customers,

and all the related amendments and applied it to all contracts that were

not

completed as of

April 1, 2018

using the modified retrospective method.

The Company’s revenues in its Grid segment are derived primarily through enabling the transmission and distribution of power, providing planning services that allow it to identify power grid needs and risks, and developing ship protection systems for the U.S. Navy. The Company’s revenues in its Wind segment are derived primarily through supplying advanced power electronics and control systems, licensing its highly engineered wind turbine designs, and providing extensive customer support services to wind turbine manufacturers. The Company records revenue based on a

five

-step model in accordance with ASC

606.

For its customer contracts, the Company identifies the performance obligations, determines the transaction price, allocates the contract transaction price to the performance obligations, and recognizes the revenue when (or as) control of goods or services is transferred to the customer. In both the

three

and

six

months ended

September 30, 2019

% of revenue was recognized at the point in time when control transferred to the customer, with the remainder being recognized over time.

In the Company's equipment and system product line, each contract with a customer summarizes each product sold to a customer, which typically represent distinct performance obligations. A contract's transaction price is allocated to each distinct performance obligation using the respective standalone selling price which is determined primarily using the cost-plus expected margin approach and recognized as revenue when, or as, the performance obligation is satisfied. The majority of the Company’s product sales transfer control to the customer in line with the contracted delivery terms and revenue is recorded at the point in time when title and risk transfer to the customer, as the Company has determined that this is the point in time that control transfers to the customer.

The Company's equipment and system product line includes certain contracts which do

not

meet the requirements of an exchange transaction and therefore do

not

fall within the scope of ASC

606.

As these non-exchange transaction contracts are considered grant revenue and do

not

fall within any specific accounting literature, the Company follows guidance within ASC

606

by analogy to recognize grant revenue over time. In the

three

and

six

months ended

September 30, 2019

, the Company recorded

$0.7

million and

$1.1

million in grant revenue, respectively, which is included in the Company’s Grid revenue. There was

grant revenue in the

three

and

six

months ended

September 30, 2018

In the Company's service and technology development product line, there are several different types of transactions and each begins with a contract with a customer that summarizes each product sold to a customer, which typically represents distinct performance obligations. The technology development transactions are primarily for activities that have

alternative use and for which a profit can be expected throughout the life of the contract. In these cases, the revenue is recognized over time, but in the instances where the profit cannot be assured throughout the entire contract then the revenue is recognized at a point in time. Each contract's transaction price is allocated to each distinct performance obligation using the respective standalone selling price which is determined primarily using the cost-plus expected margin approach. The ongoing service transactions are for service contracts that provide benefit to the customer simultaneously as the Company performs its obligations, and therefore this revenue is recognized ratably over time throughout the effective period of these contracts. The transaction prices on these contracts are allocated based on an adjusted market approach which is re-assessed annually for reasonableness. The field service transactions include contracts for delivery of goods and completion of services made at the customer's requests, which are

not

deemed satisfied until the work has been completed and/or the requested goods have been delivered, so all of this revenue is recognized at the point in time when the control changes, and at allocated prices based on the adjusted market approach driven by standard price lists. The royalty transactions are related to certain contract terms on transactions in the Company's equipment and systems product line based on activity as specified in the contracts. The transaction prices of these agreements are calculated based on an adjusted market approach as specified in the contract. The Company reports royalty revenue for usage-based royalties when the sales have occurred. In circumstances when collectability is

not

assured and a contract does

not

exist under ASC

606,

revenue is deferred until a non-refundable payment has been received for substantially all the amount that is due and there are

further remaining performance obligations.

The Company's service contracts can include a purchase order from a customer for specific goods in which each item is a distinct performance obligation satisfied at a point in time at which control of the goods is transferred to the customer. This transfer occurs based on the contracted delivery terms or when the requested service work has been completed. The transaction price for these goods is allocated based on the adjusted market approach considering similar transactions under similar circumstances. Service contracts are also derived from ongoing maintenance contracts and extended service-type warranty contracts. In these transactions, the Company is contracted to provide an ongoing service over a specified period of time. As the customer is consuming the benefits as the service is being provided, the revenue is recognized over time ratably.

The Company’s policy is to

not

accept volume discounts, product returns, or rebates and allowances within its contracts. In the event a contract was approved with any of these terms, it would be evaluated for variable consideration, estimated and recorded as a reduction of revenue in the same period the related product revenue was recorded.

The Company provides assurance-type warranties on all product sales for a term of typically

one

two

years, and extended service-type warranties at the customer's option for an additional term ranging up to

four

additional years. The Company accrues for the estimated warranty costs for assurance warranties at the time of sale based on historical warranty experience plus any known or expected changes in warranty exposure. For all extended service-type warranties, the Company recognizes the revenue ratably over time during the effective period of the services.

The Company records revenue net of sales tax, value added tax, excise tax and other taxes collected concurrent with revenue-producing activities. The Company has elected to recognize the cost for freight and shipping when control over the products sold passes to customers and revenue is recognized. The Company has elected to recognize incremental costs of obtaining a contract as expense when incurred except in contracts where the amortization period would exceed

twelve

months; in such cases the long-term amount will be assessed for materiality. The Company has elected to

not

adjust the promised amount of consideration for the effects of a significant financing component if the period of financing is

twelve

months or less.

The Company’s contracts with customers do

not

typically include extended payment terms and

may

include milestone billing over the life of the contract. Payment terms vary by contract type and type of customer and generally range from

days from delivery.

The following tables disaggregate the Company’s revenue by product line and by shipment destination:

	Three Months Ended September 30, 2019				Six Months Ended September 30, 2019
Product Line:	Grid		Wind		Grid		Wind
Equipment and systems	$	10,044	$	2,077	$	18,399	$	5,581
Services and technology development		1,445		446		2,946		856
Total	$	11,489	$	2,523	$	21,345	$	6,437

Region:
Americas	$	10,698	$	1	$	18,499	$	47
Asia Pacific		393		2,464		2,220		6,320
EMEA		398		58		626		70
Total	$	11,489	$	2,523	$	21,345	$	6,437

	Three Months Ended September 30, 2018				Six Months Ended September 30, 2018
Product Line:	Grid		Wind		Grid		Wind
Equipment and systems	$	5,503	$	7,219	$	12,957	$	10,711
Services and technology development		2,066		88		3,541		274
Total	$	7,569	$	7,307	$	16,498	$	10,985

Region:
Americas	$	5,052	$	24	$	12,548	$	47
Asia Pacific		2,308		7,278		3,115		10,873
EMEA		209		5		835		65
Total	$	7,569	$	7,307	$	16,498	$	10,985

As of

September 30, 2019

, and

September 30, 2018

, the Company’s contract assets and liabilities primarily relate to the timing differences between cash received from a customer in connection with contractual rights to invoicing and the timing of revenue recognition following completion of performance obligations. The Company's accounts receivable balance is made up entirely of customer contract related balances. Changes in the Company’s contract assets, which are included in “Unbilled Accounts Receivable” and “Deferred program costs” (see Note

“Accounts Receivable” and Note

“Inventory” for a reconciliation to the condensed consolidated balance sheets) and contract liabilities, which are included in the current portion and long term portion of deferred revenue in the Company’s condensed consolidated balance sheets, are as follows:

	Unbilled Accounts Receivable			Deferred Program Costs			Contract Liabilities
Beginning balance as of March 31, 2019	$	2,213		$	318		$	15,519
Increases for costs incurred to fulfill performance obligations		—			2,153			—
Increase (decrease) due to customer billings		(2,926	)		—			19,340
Decrease due to cost recognition on completed performance obligations		—			(310	)		—
Increase (decrease) due to recognition of revenue based on transfer of control of performance obligations		4,711			—			(18,534	)
Other changes and FX impact		(4	)		(9	)		(313	)
Ending balance as of September 30, 2019	$	3,994		$	2,152		$	16,012

	Unbilled Accounts Receivable			Deferred Program Costs			Contract Liabilities
Beginning balance as of March 31, 2018	$	3,016		$	2,567		$	21,937
Impact of adoption of ASC 606		—			(1,599	)		(2,657	)
Increases for costs incurred to fulfill performance obligations		—			1,267			—
Increase (decrease) due to customer billings		(7,886	)		—			7,828
Decrease due to cost recognition on completed performance obligations		—			(1,033	)		—
Increase (decrease) due to recognition of revenue based on transfer of control of performance obligations		7,439			(9	)		(8,296	)
Other changes and FX impact		(19	)		24			(864	)
Ending balance as of September 30, 2018	$	2,550		$	1,217		$	17,948

The Company’s remaining performance obligations represent the unrecognized revenue value of the Company’s contractual commitments. The Company’s performance obligations

may

vary significantly each reporting period based on the timing of major new contractual commitments. As of

September 30, 2019

, the Company had outstanding performance obligations on existing contracts under ASC

606

to be recognized in the next

twelve

months of approximately $

50.4

million. There are also approximately $

7.2

million of outstanding performance obligations to be recognized over a period of

thirteen

sixty

months. The remaining performance obligations are subject to customer actions and therefore the timing of revenue recognition cannot be reasonably estimated. The

twelve

-month performance obligations include anticipated shipments to Inox based on the

twelve

-month rolling forecast provided by Inox on the multi-year supply contract. The quantities specified in any forecast provided by Inox related to the multi-year supply contract are firm and irrevocable for the

first

three

months of a

twelve

-month rolling forecast. The timing of the performance obligations beyond the

twelve

-month forecast provided by Inox are

not

determinable and therefore are

not

included in the total remaining performance obligations.

The following table sets forth customers who represented

10%

or more of the Company’s total revenues for

three

and

six

months ended

September 30, 2019

and

2018

		Three Months Ended						Six Months Ended
	Reportable	September 30,						September 30,
	Segment	2019			2018			2019			2018
Inox Wind Limited	Wind		<10%			45	%		17	%		36	%
Micron Technology	Grid		<10%			<10%			14	%		<10%
Vestas	Grid		<10%			11	%		<10%			23	%
Quanta Power	Grid		—	%		12	%		—	%		<10%
Hoffman Construction	Grid		25	%		—	%		12	%		—	%
M.J. Electric, LLC	Grid		25	%		—	%		13	%		—	%

Note 3 - Stock-based Compensation

6 Months Ended

Sep. 30, 2019

Notes to Financial Statements

Share-based Payment Arrangement [Text Block]

Stock-Based Compensation

The Company accounts for its stock-based compensation at fair value. The following table summarizes stock-based compensation expense by financial statement line item for the

three

and

six

months ended

September 30, 2019

and

2018

(in thousands):

	Three Months Ended September 30,				Six Months Ended September 30,
	2019		2018		2019		2018
Cost of revenues	$	21	$	50	$	24	$	90
Research and development		92		70		103		121
Selling, general and administrative		283		705		519		1,399
Total	$	397	$	825	$	646	$	1,610

The Company issued

13,174

shares of immediately vested common stock and

170,500

shares of restricted stock awards during the

six

months ended

September 30, 2019

and issued

37,075

shares of immediately vested common stock and

413,000

shares of restricted stock awards during the

six

months ended

September 30, 2018

. These restricted stock awards generally vest over

years. Awards for restricted stock include both time-based and performance-based awards. For options and restricted stock awards that vest upon the passage of time, expense is being recorded over the vesting period. Performance-based awards are expensed over the requisite service period based on probability of achievement.

The estimated fair value of the Company’s stock-based awards, less expected annual forfeitures, is amortized over the awards’ service period. The total unrecognized compensation cost for unvested outstanding stock options was less than $

0.1

million at

September 30, 2019

. This expense will be recognized over a weighted average expense period of approximately

1.7

years. The total unrecognized compensation cost for unvested outstanding restricted stock was $

3.1

million at

September 30, 2019

. This expense will be recognized over a weighted-average expense period of approximately

1.4

years.

The Company granted

5,939

stock options during the

six

months ended

September 30, 2019

. The Company did

not

grant any stock options during the

three

months ended

September 30, 2019

or the

three

and

six

months ended

September 30, 2018

. The stock options granted during the

six

months ended

September 30, 2019

will vest over

ars. The weighted average assumptions used in the Black Scholes valuation model for stock options granted during the

six

months ended

September 30, 2019

are as follows:

Three Months Ended September 30,

Six Months Ended September 30,

2019

2018

2019

2018

Expected volatility

N/A

66.5

N/A

Risk-free interest rate

N/A

1.8

N/A

Expected life (years)

N/A

5.91

N/A

Dividend yield

N/A

None

N/A

Note 4 - Computation of Net Loss per Common Share

6 Months Ended

Sep. 30, 2019

Notes to Financial Statements

Earnings Per Share [Text Block]

Computation of Net Loss per Common Share

Basic net loss per share (“EPS”) is computed by dividing net loss by the weighted-average number of common shares outstanding for the period. Where applicable, diluted EPS is computed by dividing the net loss by the weighted-average number of common shares and dilutive common equivalent shares outstanding during the period, calculated using the treasury stock method. Common equivalent shares include the effect of restricted stock, exercise of stock options and warrants and contingently issuable shares. Stock options and warrants that are out-of-the-money with exercise prices greater than the average market price of the underlying common shares and shares of performance based restricted stock where the contingency was

not

met are excluded from the computation of diluted EPS as the effect of their inclusion would be anti-dilutive. For both the

three

and

six

months ended

September 30, 2019

0.2

million shares related to stock options were

not

included in the calculation of diluted EPS as they were considered anti-dilutive. For the

three

months ended

September 30, 2018

1.6

million shares were

not

included in the calculation of diluted EPS as they were considered anti-dilutive, of which

0.3

million relate to outstanding stock options,

0.9

million relate to outstanding warrants and

0.4

million relate to outstanding unvested stock awards. For the

six

months ended

September 30, 2018

1.4

million shares were

not

included in the calculation of diluted EPS as they were considered anti-dilutive, of which

0.2

million shares relate to outstanding stock options,

0.9

million shares relate to outstanding warrants and

0.3

million relate to outstanding unvested stock awards.

The following table reconciles the numerators and denominators of the earnings per share calculation for the

three

and

six

months ended

September 30, 2019

and

2018

(in thousands, except per share data):

	Three Months Ended September 30,						Six Months Ended September 30,
	2019			2018			2019			2018
Numerator:
Net (loss) income	$	(825	)	$	22,558		$	(4,364	)	$	17,821
Less: decrease in fair value of warrants, net of income tax		(1,145	)		0			(4,092	)		0
Plus: change in fair value due to exercise of warrants		0			0			83			0
Net income (loss) - diluted	$	(1,970	)	$	22,558		$	(8,373	)	$	17,821
Denominator:
Weighted-average shares of common stock outstanding		21,678			21,252			21,538			21,126
Weighted-average shares subject to repurchase		(1,022	)		(939	)		(952	)		(886	)
Shares used in per-share calculation ― basic		20,656			20,313			20,586			20,240
Common stock awards		0			268			0			320
Common stock warrants		67			0			150			0
Shares used in per-share calculation ― diluted		20,723			20,581			20,736			20,560
Net (loss) income per share ― basic	$	(0.04	)	$	1.11		$	(0.21	)	$	0.88
Net (loss) income per share ― diluted	$	(0.10	)	$	1.10		$	(0.40	)	$	0.87

For the

three

and

six

months ended

September 30, 2019,

the diluted net loss per common share amounts under the treasury stock method were calculated based on the dilutive effect of the total number of shares of common stock related to the Hudson Warrant of

818,181

shares with an exercise price of

7.81

For the

three

and

six

month periods ended

September 30, 2019,

the average stock price was

$8.50

and

$9.56

respectively, providing

66,638

and

150,025

dilutive shares respectively, for the Hudson Warrant. The decrease in the fair value of the warrant liability of

$1.1

million and

$4.1

million, respectively, is included in the net loss available to common shareholders for the diluted net loss per common share amount when the impact is dilutive.

Note 6 - Fair Value Measurements

6 Months Ended

Sep. 30, 2019

Notes to Financial Statements

Fair Value Disclosures [Text Block]

Fair Value Measurements

A valuation hierarchy for disclosure of the inputs to valuation used to measure fair value has been established. This hierarchy prioritizes the inputs into

three

broad levels as follows:

Level 1	-	Inputs are unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date.

Level 2	-	Inputs include quoted prices for similar assets and liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability, and inputs that are derived principally from or corroborated by observable market data by correlation or other means (market corroborated inputs).

Level 3	-	Unobservable inputs that reflect the Company’s assumptions that market participants would use in pricing the asset or liability. The Company develops these inputs based on the best information available, including its own data.

The Company provides a gross presentation of activity within Level

measurement roll-forward and details of transfers in and out of Level

and

measurements. A change in the hierarchy of an investment from its current level is reflected in the period during which the pricing methodology of such investment changes. Disclosure of the transfer of securities from Level

to Level

or Level

is made in the event that the related security is significant to total cash and investments. The Company did

not

have any transfers of assets and liabilities from Level

Level

or Level

of the fair value measurement hierarchy during the

six

months ended

September 30, 2019

A financial asset’s or liability’s classification within the hierarchy is determined based on the lowest level input that is significant to the fair value measurement.

The following table provides the assets and liabilities carried at fair value on a recurring basis, measured as of

September 30, 2019

and

March 31, 2019

(in thousands):

	Total Carrying Value		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
September 30, 2019:
Assets:
Cash equivalents	$	49,034	$	49,034	$	—	$	—
Marketable securities	$	10,000	$	10,000	$	—	$	—
Derivative liabilities:
Warrants	$	556	$	—	$	—	$	556

	Total Carrying Value		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
March 31, 2019:
Assets:
Cash equivalents	$	41,839	$	41,839	$	—	$	—
Derivative liabilities:
Warrants	$	4,942	$	—	$	—	$	4,942

The table below reflects the activity for the Company’s major classes of liabilities measured at fair value on a recurring basis (in thousands):

	Warrants
April 1, 2019	$	4,942
Mark to market adjustment		(4,092	)
Warrant exercise		(294	)
Balance at September 30, 2019	$	556

	Warrants
April 1, 2018	$	1,217
Mark to market adjustment		182
Balance at September 30, 2018	$	1,399

Valuation Techniques

Cash Equivalents

Cash equivalents consist of highly liquid instruments with maturities of

three

months or less that are regarded as high quality, low risk investments, are measured using such inputs as quoted prices and are classified within Level

of the valuation hierarchy. Cash equivalents consist principally of certificates of deposits and money market accounts.

Marketable Securities

Marketable securities consist of certificates of deposit with maturities of greater than

months that are measured using such inputs as quoted prices and are classified within Level

of the valuation hierarchy. The Company determines the appropriate classification of its marketable securities at the time of purchase and re-evaluates such classification as of each balance sheet date. All marketable securities are considered available for sale and are carried at fair value. The Company periodically reviews the realizability of each short and long term marketable security when impairment indicators exist with respect to the security. If other than temporary impairment of value of the security exists, the carrying value of the security is written down to its estimated fair value.

Warrants

Warrants were issued in conjunction with an equity offering to Hudson Bay Capital in

November 2014

and a Loan and Security Agreement with Hercules Technology Growth Capital, Inc. (“Hercules”). The warrants issued to Hercules were exercised on

April 8, 2019.

Outstanding warrants are subject to revaluation at each balance sheet date, and any change in fair value will be recorded as a change in fair value in derivatives and warrants until the earlier of their exercise or expiration.

The Company relies on various assumptions in a lattice model to determine the fair value of warrants. The Company has valued the warrants within Level

of the valuation hierarchy. See Note

13,

“Warrants and Derivative Liabilities,” for additional information including a discussion of the warrants and the valuation assumptions used.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Note 8 - Inventory

6 Months Ended

Sep. 30, 2019

Notes to Financial Statements

Inventory Disclosure [Text Block]

Inventory

Inventory, net of reserves, at

September 30, 2019

and

March 31, 2019

consisted of the following (in thousands):

	September 30, 2019		March 31, 2019
Raw materials	$	7,421	$	5,474
Work-in-process		1,943		1,922
Finished goods		3,981		4,405
Deferred program costs		2,152		318
Net inventory	$	15,497	$	12,119

The Company recorded inventory write-downs of $

0.1

million and

$0.4

million for the

three

months ended

September 30, 2019

and

2018

, respectively. The Company recorded inventory write-downs of $

0.2

million and

$0.5

million for the

six

months ended

September 30, 2019

and

2018

, respectively. These write-downs were based on the Company's evaluation of its inventory on hand for excess quantities and obsolescence.

Deferred program costs as of

September 30, 2019

and

March 31, 2019

primarily represent costs incurred on programs where the Company needs to complete performance obligations before the related revenue and costs will be recognized.

Note 9 - Note Receivable

6 Months Ended

Sep. 30, 2019

Notes to Financial Statements

Notes Receivable [Text Block]

Note Receivable

The Company entered into the PSA dated

February 1, 2018,

for the sale of the Devens facility (including land, building and building improvements) located at

Jackson Road, Devens, Massachusetts to

Jackson, LLC, a limited liability company (subsequently assigned to Jackson

MGI, LLC) in the amount of

$23.0

million. The terms for payment included a

$1.0

million security deposit, and a note receivable for

$6.0

million payable to the Company with the remaining cash, net of certain adjustments for closing costs, at the date of settlement. The note receivable was due in

two

$3.0

million installments plus accrued interest at a rate of

1.96%

March 31, 2019

and

March 31, 2020.

The note was subordinate to East Boston Savings Bank's mortgage on the Devens property. The

first

installment was paid on

March 28, 2019

and the

second

installment was paid on

May 23, 2019.

The note receivable was discounted to its present value of

$5.7

million utilizing a discount rate of

6%,

which was based on management’s assessment of what an appropriate loan at current market rates would be. The

$0.3

million discount was recorded as an offset to the long-term portion of the note receivable. In addition, the resulting gain of

$0.1

million from the sale of the Devens property which was deferred previously was recorded as a component of the cumulative effect of an accounting change upon the adoption of Accounting Standards Update ("ASU")

2017

Other Income - Gains and Losses from the Derecognition of Non-financial Assets (Subtopic

610

)

which was issued as a part of ASU

2014

Revenue from Contracts with Customers (Topic

606

)

. This gain was recorded as an offset to the opening accumulated deficit as of

April 1, 2018.

Note receivable as of

September 30, 2019

and

March 31, 2019

consisted of the following (in thousands):

Current assets	September 30, 2019		March 31, 2019
Note receivable, current	$	—	$	3,000
Note receivable discount		—		(112	)
Total current note receivable	$	—	$	2,888

Note 10 - Property, Plant and Equipment

6 Months Ended

Sep. 30, 2019

Notes to Financial Statements

Property, Plant and Equipment Disclosure [Text Block]

10.

Property, Plant and Equipment

The cost and accumulated depreciation of property, plant and equipment at

September 30, 2019

and

March 31, 2019

are as follows (in thousands):

	September 30, 2019			March 31, 2019
Construction in progress - equipment	$	2,223		$	603
Equipment and software		45,127			45,705
Furniture and fixtures		1,259			1,269
Leasehold improvements		1,976			1,955
Property, plant and equipment, gross		50,585			49,532
Less accumulated depreciation		(41,975	)		(40,560	)
Property, plant and equipment, net	$	8,610		$	8,972

Depreciation expense was $

1.0

million and

$1.1

million for the

three

months ended

September 30, 2019

and

2018

, respectively. Depreciation expense was $

2.1

million and

$2.1

million for the

six

months ended

September 30, 2019

and

2018

, respectively. Construction in progress - equipment primarily includes capital investments and leasehold improvements in the Company's leased facility in Ayer, Massachusetts.

Note 11 - Accounts Payable and Accrued Expenses

6 Months Ended

Sep. 30, 2019

Notes to Financial Statements

Accounts Payable and Accrued Liabilities Disclosure [Text Block]

11.

Accounts Payable and Accrued Expenses

Accounts payable and accrued expenses at

September 30, 2019

and

March 31, 2019

consisted of the following (in thousands):

	September 30, 2019		March 31, 2019
Accounts payable	$	6,164	$	2,939
Accrued inventories in-transit		603		244
Accrued other miscellaneous expenses		1,772		1,759
Advanced deposits		1,771		631
Accrued compensation		3,730		5,404
Income taxes payable		3,043		3,363
Accrued product warranty		1,641		1,545
Total	$	18,724	$	15,885

The Company generally provides a

one

three

year warranty on its products, commencing upon delivery or installation where applicable. A provision is recorded upon revenue recognition to cost of revenues for estimated warranty expense based on historical experience.

Product warranty activity was as follows (in thousands):

	Three Months Ended September 30,						Six Months Ended September 30,
	2019			2018			2019			2018
Balance at beginning of period	$	1,606		$	1,752		$	1,545		$	1,769
Change in accruals for warranties during the period		71			213			156			317
Settlements during the period		(36	)		(205	)		(60	)		(326	)
Balance at end of period	$	1,641		$	1,760		$	1,641		$	1,760

Note 12 - Income Taxes	6 Months Ended
Note 12 - Income Taxes	Sep. 30, 2019
Notes to Financial Statements
Income Tax Disclosure [Text Block]	12. Income Taxes The Company recorded an income tax benefit of $ 0.3 million and expense of $3.0 million in the three months ended September 30, 2019 and 2018 , respectively. The Company recorded an income tax benefit of $ 0.1 million and expense of $3.0 million in the six months ended September 30, 2019 and 2018 , respectively. Accounting for income taxes requires a two -step approach to recognizing and measuring uncertain tax positions. The first step is to evaluate the tax position for recognition by determining if, based on the technical merits, it is more likely than not the position will be sustained upon audit, including resolution of related appeals or litigation processes, if any. The second step is to measure the tax benefit as the largest amount that is more than 50% likely to be realized upon ultimate settlement. The Company re-evaluates these uncertain tax positions on a quarterly basis. The evaluation is based on factors including, but not limited to, changes in facts or circumstances, changes in tax law, effectively settled issues under audit and new audit activity. Any changes in these factors could result in the recognition of a tax benefit or an additional charge to the tax provision. The Company did not identify any uncertain tax positions in the six months ended September 30, 2019 and did not have any gross unrecognized tax benefits as of March 31, 2019 .

Note 13 - Warrants and Derivative Liabilities

6 Months Ended

Sep. 30, 2019

Notes to Financial Statements

Derivative Instruments and Hedging Activities Disclosure [Text Block]

13.

Warrants and Derivative Liabilities

The Company accounts for its warrants and contingent consideration as liabilities due to certain adjustment provisions within the instruments, which require that they be recorded at fair value. The warrants are subject to revaluation at each balance sheet date and any change in fair value is recorded as a change in fair value of warrants until the earlier of its expiration or its exercise at which time the warrant liability will be reclassified to equity. The Company calculated the fair value of the warrants utilizing an integrated lattice model. See Note

"Fair Value Measurements", for further discussion.

Hercules Warrants

December 19, 2014,

the Company entered into a

second

amendment to the Loan and Security Agreement with Hercules (the "Hercules Second Amendment"). In conjunction with the Hercules Second Amendment, the Company issued Hercules a warrant to purchase

58,823

shares of the Company’s common stock (the "Hercules Warrant") which replaced the First Warrant and the Second Warrant. The Hercules Warrant was exercisable at any time after its issuance at an exercise price of

$7.85

per share, subject to certain price-based and other anti-dilution adjustments, including the equity offering in

May 2017,

the acquisition of ITC with common stock in

September 2017

and sales of common stock under the ATM entered into in

January 2017.

This warrant had a fair value of

$0.4

million as of

March 31, 2019.

April 8, 2019,

Hercules notified the Company of its intent to exercise this warrant on a cashless basis. Hercules received

22,821

shares of the Company's common stock on

April 17, 2019.

As a result of this exercise the Company recorded a net gain of

$0.1

million to change in fair value of warrants, resulting from the decrease in the fair value upon exercise of the Hercules Warrant during the

six

months ended

September 30, 2019

November 2014

Warrant

November 13, 2014,

the Company completed an offering of

909,090

units of the Company’s common stock with Hudson Bay Capital. Each unit consisted of

one

share of the Company’s common stock and

0.9

of a warrant to purchase

one

share of common stock, or a warrant to purchase in the aggregate

818,181

shares (the

“November 2014

Warrant”). The

November 2014

Warrant is exercisable at any time, at an exercise price equal to

$7.81

per share, subject to certain price-based and other anti-dilution adjustments including those noted above and expires on

November

13,

2019.

Following is a summary of the key assumptions used to calculate the fair value of the

November 2014

Warrant:

	September 30,			June 30,
Fiscal Year 2019		2019			2019
Risk-free interest rate		1.90	%		2.11	%
Expected annual dividend yield		—			—
Expected volatility		62.84	%		60.58	%
Term (years)		0.12			0.37
Fair value	$0.6 million			$1.7 million

	March 31,	December 31,	September 30,	June 30,	March 31,
Fiscal Year 2018	2019	2018	2018	2018	2018
Risk-free interest rate	2.43%	2.61%	2.62%	2.40%	2.20%
Expected annual dividend yield	—	—	—	—	—
Expected volatility	75.61%	70.29%	63.66%	67.40%	65.86%
Term (years)	0.62	0.87	1.12	1.37	1.62
Fair value	$4.6 million	$3.6 million	$1.3 million	$1.6 million	$1.1 million

The Company recorded net

gains

of $

1.1

million and $

4.1

million resulting from the

decreases

in the fair value of the

November 2014

Warrant during the

three

and

six

months ended

September 30, 2019

, respectively. The Company recorded a net gain of

$0.3

million and net loss of

$0.2

million resulting from the changes in the fair value of the

November 2014

Warrant during the

three

and

six

months ended

September 30, 2018

, respectively.

Note 14 - Leases

6 Months Ended

Sep. 30, 2019

Notes to Financial Statements

Lessee, Operating Leases [Text Block]

14.

Leases

April 1, 2019,

the Company adopted ASU

2016

02,

Leases (Topic

842

)

("ASC

842"

), using the modified retrospective approach. The Company elected the package of practical expedients available in the standard and as a result, did

not

reassess the lease classification of existing contracts or leases or the initial direct costs associated with existing leases. The Company did

not

elect the hindsight practical expedient and evaluated lease terms for existing leases. The Company has also elected the practical expedient to

not

separate lease components and non-lease components and will account for the leases as a single lease component for all classes of leases.

As a result of the adoption of ASC

842,

the Company recognized lease right-of-use assets of

$3.8

million, and operating lease liabilities of

$3.8

million. There was

impact to the condensed consolidated statements of operations or stockholders' equity for the adoption of ASC

842.

impairment was recognized on the right-of-use asset upon adoption. These adjustments are detailed as follows:

	March 31, 2019		ASC 842 Adjustment		April 1, 2019
Operating Leases:
Right of use asset	$	—	$	3,795	$	3,795
Total operating lease right-of-use asset		—		3,795		3,795

Operating lease liabilities – ST	$	—	$	309	$	309
Operating lease liabilities – LT		—		3,512		3,512
Total operating lease liabilities		—		3,821		3,821

Weighted-average remaining lease term					7.69 years
Weighted-average discount rate						7.06	%

All significant lease arrangements are recognized at lease commencement. Operating lease right–of-use assets and lease liabilities are recognized at commencement. The operating lease right-of-use asset includes any lease payments related to initial direct cost and prepayments and excludes any lease incentives. Lease expense is recognized on a straight-line basis over the lease term. The Company enters into a variety of operating lease agreements through the normal course of its business, but primarily real estate leases to support its operations. The agreements generally provide for fixed minimum rental payments and the payment of real estate taxes and insurance. Many of these leases have

one

or more renewal options that allow the Company, at its discretion, to renew the lease for varying periods up to

five

years or to terminate the lease. Only renewal options or termination rights that the Company believed were likely to be exercised were included in the lease calculations.

The Company also enters into leases for vehicles, IT equipment and service agreements, and other leases related to its manufacturing operations that are also included in the right-of-use asset and lease liability accounts if they are for a term of longer than

twelve

months. However, many of these leases are either short-term in nature or immaterial. The Company has made the policy election to exclude short term leases from the balance sheet.

The discount rate was calculated using an incremental borrowing rate based on an assessment prepared by the Company through the use of Company credit ratings, consideration of its lease populations potential risk to its total capital structure, and a market rate for a collateralized loan for its risk profile, calculated by a

third

party. The Company elected to apply the discount rate using the remaining lease term at the date of adoption.

The Company did

not

identify any leases that are classified as financing leases.

Supplemental balance sheet information related to leases at

September 30, 2019

are as follows:

	September 30, 2019
Operating Leases:
Right-of-use assets	$	3,607
Total right-of-use assets		3,607

Lease liabilities - ST	$	424
Lease liabilities - LT		3,240
Total operating lease liabilities		3,664

Weighted-average remaining lease term		7.31 years
Weighted-average discount rate		7.07	%

The costs related to the Company's leases for the

three

and

six

months ended

September 30, 2019

are as follows:

	Three Months Ended		Six Months Ended
	September 30, 2019		September 30, 2019
Operating Lease:
Operating lease costs - fixed	$	178	$	356
Operating lease costs - variable		27		46
Short-term lease costs		176		214
Total lease costs		381		616

The Company’s estimated minimum future lease obligations under the Company's leases are as follows:

	Operating Leases
Year ended March 31,
2020	$	331
2021		670
2022		650
2023		624
2024		562
Thereafter		1,896
Total minimum lease payments		4,733
Less: interest		(1,069	)
Present value of lease liabilities		3,664

Note 15 - Commitments and Contingencies	6 Months Ended
Note 15 - Commitments and Contingencies	Sep. 30, 2019
Notes to Financial Statements
Commitments and Contingencies Disclosure [Text Block]	15. Commitments and Contingencies Legal Contingencies From time to time, the Company is involved in legal and administrative proceedings and claims of various types. The Company records a liability in its consolidated financial statements for these matters when a loss is known or considered probable and the amount can be reasonably estimated. The Company reviews these estimates each accounting period as additional information is known and adjusts the loss provision when appropriate. If a matter is both probable to result in a liability and the amounts of loss can be reasonably estimated, the Company estimates and discloses the possible loss or range of loss to the extent necessary to make the consolidated financial statements not misleading. If the loss is not probable or cannot be reasonably estimated, a liability is not recorded in its consolidated financial statements. Other The Company enters into long-term construction contracts with customers that require the Company to obtain performance bonds. The Company is required to deposit an amount equivalent to some or all the face amount of the performance bonds into an escrow account until the termination of the bond. When the performance conditions are met, amounts deposited as collateral for the performance bonds are returned to the Company. In addition, the Company has various contractual arrangements in which minimum quantities of goods or services have been committed to be purchased on an annual basis. As of September 30, 2019 , the Company had $ 5.7 million of restricted cash included in long-term assets. These amounts included in restricted cash primarily represent deposits to secure letters of credit for various supply contracts. These deposits are held in interest bearing accounts. As part of the agreement with Commonwealth Edison Company to install the Resilient Electric Grid ("REG") system in Chicago, the Company agreed to deliver an irrevocable letter of credit in the amount of $5.0 million to secure certain Company obligations under the Subcontract Agreement. The funds to secure the $5.0 million letter of credit were deposited in an escrow account on July 1, 2019.

Note 16 - Restructuring

6 Months Ended

Sep. 30, 2019

Notes to Financial Statements

Restructuring and Related Activities Disclosure [Text Block]

16.

Restructuring

The Company accounts for charges resulting from operational restructuring actions in accordance with ASC Topic

420,

Exit or Disposal Cost Obligations

(“ASC

420”

) and ASC Topic

712,

Compensation—Nonretirement Postemployment Benefits

(“ASC

712”

). In accounting for these obligations, the Company is required to make assumptions related to the amounts of employee severance, benefits, and related costs and the time period over which leased facilities will remain vacant, sublease terms, sublease rates and discount rates. Estimates and assumptions are based on the best information available at the time the obligation arises. These estimates are reviewed and revised as facts and circumstances dictate; changes in these estimates could have a material effect on the amount accrued on the consolidated balance sheet.

The

$0.4

million charged to operations in the

six

months ended

September 30, 2018

is related to exit costs incurred in connection with the move of the Company's corporate office.

The following table presents restructuring charges and cash payments for the

six

months ended

September 30, 2018

(in thousands):

	Severance pay			Facility exit and
	and benefits			Relocation costs			Total
Accrued restructuring balance at April 1, 2018	$	262		$	173		$	435
Charges to operations		—			403			403
Cash payments		(173	)		(576	)		(749	)
Accrued restructuring balance at September 30, 2018	$	89		$	—		$	89

All restructuring charges discussed above are included within restructuring in the Company’s unaudited condensed consolidated statements of operations. The Company includes accrued restructuring within accounts payable and accrued expenses. There was

restructuring activity in the

six

months ending

September 30, 2019

or any remaining accrued restructuring balance as of

September 30, 2019

Note 17 - Business Segments

6 Months Ended

Sep. 30, 2019

Notes to Financial Statements

Segment Reporting Disclosure [Text Block]

17.

Business Segments

The Company reports its financial results in

two

reportable business segments: Grid and Wind.

Through the Company’s power grid offerings, the Grid business segment enables electric utilities, industrial facilities, and renewable energy project developers to connect, transmit and distribute power through our transmission planning services, power electronics, and superconductor-based systems. The sales process is enabled by transmission planning services that allow it to identify power grid congestion, poor power quality and other risks, which helps the Company determine how its solutions can improve network performance. These services often lead to sales of grid interconnection solutions for wind farms and solar power plants, power quality systems, and transmission and distribution cable systems. The Company also sells ship protection products to the U.S. Navy through its Grid business segment.

Through the Company’s wind power offerings, the Wind business segment enables manufacturers to field highly competitive wind turbines through our advanced power electronics and control system products, engineered designs, and support services. The Company supplies advanced power electronics and control systems, licenses its highly engineered wind turbine designs, and provides extensive customer support services to wind turbine manufacturers. The Company’s design portfolio includes a broad range of drive trains and power ratings of

megawatts ("MWs") and higher. The Company provides a broad range of power electronics and software-based control systems that are highly integrated and designed for optimized performance, efficiency, and grid compatibility.

The operating results for the

two

business segments are as follows (in thousands):

	Three Months Ended September 30,				Six Months Ended September 30,
	2019		2018		2019		2018
Revenues:
Grid	$	11,489	$	7,569	$	21,345	$	16,498
Wind		2,523		7,307		6,437		10,985
Total	$	14,012	$	14,876	$	27,782	$	27,483

	Three Months Ended September 30,						Six Months Ended September 30,
	2019			2018			2019			2018
Operating (loss) income:
Grid	$	(1,324	)	$	(2,870	)	$	(5,988	)	$	(5,537	)
Wind		(2,398	)		28,515			(3,721	)		27,150
Unallocated corporate expenses		(397	)		(918	)		(646	)		(2,013	)
Total	$	(4,119	)	$	24,727		$	(10,355	)	$	19,600

The accounting policies of the business segments are the same as those for the consolidated Company. The Company’s business segments have been determined in accordance with the Company’s internal management structure, which is organized based on operating activities. The Company evaluates performance based upon several factors, of which the primary financial measures are segment revenues and segment operating loss. The disaggregated financial results of the segments reflect allocation of certain functional expense categories consistent with the basis and manner in which Company management internally disaggregates financial information for the purpose of assisting in making internal operating decisions. In addition, certain corporate expenses which the Company does

not

believe are specifically attributable or allocable to either of the

two

business segments have been excluded from the segment operating loss.

Unallocated corporate expenses primarily consist of stock-based compensation expense of $

0.4

million and

$0.8

million in the

three

months ended

September 30, 2019

and

2018

, respectively, and restructuring charges of

$0.1

million in the

three

months ended

September 30, 2018

. Unallocated corporate expenses primarily consist of stock-based compensation expense of $

0.6

million and

$1.6

million in the

six

months ended

September 30, 2019

and

2018

, respectively, and restructuring charges of

$0.4

million in the

six

months ended

September 30, 2018

Total assets for the

two

business segments as of

September 30, 2019

and

March 31, 2019

are as follows (in thousands):

	September 30, 2019		March 31, 2019
Grid	$	34,479	$	31,075
Wind		12,474		8,167
Corporate assets		70,490		80,088
Total	$	117,443	$	119,330

Note 18 - Recent Accounting Pronouncements

6 Months Ended

Sep. 30, 2019

Notes to Financial Statements

New Accounting Pronouncements and Changes in Accounting Principles [Text Block]

18.

Recent Accounting Pronouncements

February 2016,

the FASB issued ASU

2016

02,

Leases (Topic

842

)

. The guidance in this ASU supersedes the leasing guidance in Topic

840,

Leases

. Under the new guidance, lessees are required to recognize lease assets and lease liabilities on the balance sheet for all leases with terms longer than

months. Leases will be classified as either finance or operating, with classification affecting the pattern of expense recognition in the income statement. This ASU and its amendments are effective for fiscal years beginning after

December 15, 2018,

including interim periods within those fiscal years.

•

July 2018,

the FASB issued ASU

2018

10,

Codification improvements to Topic

842,

Leases.

The amendments in ASU

2018

provide more clarification in regards to the application and requirements of ASU

2016

02.

•

July 2018,

the FASB issued ASU

2018

11,

Topic

842,

Leases - Targeted improvements.

The amendments in ASU

2018

provide for the option to adopt the standard prospectively and recognize a cumulative-effect adjustment to the opening balance of retained earnings as well as offer a new practical expedient that will allow the Company to elect, by class of underlying asset, to

not

separate non-lease and lease components in certain circumstances and instead to account for those components as a single item.

ASU

2016

became effective on

April 1, 2019,

and the Company adopted the standard using the modified retrospective transition method, which impacted all leases existing at, or entered into after, the period of adoption. For all leases existing at the time of adoption the Company recognized a right-of-use asset and lease liability on the balance sheet. See Note

"Leases" for additional information.

June 2016,

the FASB issued ASU

2016

13,

Financial Instruments-Credit Losses (Topic

326

): Measurement of Credit Losses on Financial Instruments

. The amendments in ASU

2016

will provide more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. The ASU is effective for annual reporting periods beginning after

December 15, 2019,

including interim periods within that year. The Company is currently evaluating the impact, if any, the adoption of ASU

2016

may

have on its consolidated financial statements.

July 2017,

the FASB issued ASU

2017

11,

Earnings per Share (Topic

260

Distinguishing Liabilities from Equity (Topic

480

), and Derivatives and Hedging (Topic

815

)

. The amendments in ASU

2017

provide guidance for freestanding equity-linked financial instruments, such as warrants and conversion options in convertible debt or preferred stock and should

longer be accounted for as a derivative liability at fair value as a result of the existence of a down round feature. The ASU is effective for annual reporting periods beginning after

December 15, 2018,

including interim periods within those periods. As of

April 1, 2019,

the Company has adopted ASU

2017

and noted

significant impact on its consolidated financial statements, primarily due to the put option feature within the Company's warrant agreements which requires continued liability classification under ASC

480.

August 2017,

the FASB issued ASU

2017

12,

Derivatives and Hedging (Topic

815

): Targeted Improvements to Accounting for Hedging Activities

. The amendments in ASU

2017

provide improved financial reporting of hedging relationships to better portray the economic results of an entity’s risk management activities in its financial statements. In addition, the amendments in this update make certain targeted improvements to simplify the application of the hedge accounting guidance. The ASU is effective for annual reporting periods beginning after

December 15, 2018,

including interim periods within those periods. As of

April 1, 2019,

the Company has adopted ASU

2017

and noted

significant impact on its consolidated financial statements, primarily due to the fact that there are

longer any hedging instruments included in its results.

June 2018,

the FASB issued ASU

2018

08,

Not

-For-Profit Entities (Topic

958

): Clarifying the Scope and the Accounting Guidance for Contributions Received and Contributions Made

. The amendments in ASU

2018

assist entities in (

) evaluating whether transactions should be accounted for as contributions (nonreciprocal transactions) within the scope of Topic

958,

Not

-for-Profit Entities, or as exchange (reciprocal) transactions subject to other guidance and (

) determining whether a contribution is conditional. The ASU is effective for annual reporting periods beginning after

December 15, 2018,

including interim periods within those periods. As of

April 1, 2019,

the Company has adopted ASU

2018

and noted additional disclosures within its revenue footnote to appropriately present the revenue related to its grant revenue.

August 2018,

the FASB issued ASU

2018

13,

Fair Value Measurement (Topic

820

): Changes to the Disclosure Requirements for Fair Value Measurement

. The amendments in ASU

2018

provide for increased effectiveness of the disclosures made around fair value measurements while including consideration for costs and benefits. The ASU is effective for annual reporting periods beginning after

December 15, 2019,

including interim periods within those periods. The Company is currently evaluating the impact the adoption of ASU

2018

may

have on its consolidated financial statements.

Significant Accounting Policies (Policies)	6 Months Ended
Significant Accounting Policies (Policies)	Sep. 30, 2019
Accounting Policies [Abstract]
Nature of Business and Operations, Policy [Policy Text Block]	Nature of the Business and Operations American Superconductor Corporation (together with its subsidiaries, “AMSC®”or the “Company”) was founded on April 9, 1987. The Company is a leading system provider of megawatt-scale power solutions that enhance the performance of the power grid, protect the Navy’s fleet, and lower the cost of wind power. The Company’s system level products leverage its proprietary “smart materials” and “smart software and controls” to provide enhanced resiliency and improved performance of megawatt-scale power flow. These unaudited condensed consolidated financial statements of the Company have been prepared on a going concern basis in accordance with United States generally accepted accounting principles (“GAAP”) and the Securities and Exchange Commission’s (“SEC”) instructions to Form 10 -Q. The going concern basis of presentation assumes that the Company will continue operations and will be able to realize its assets and discharge its liabilities and commitments in the normal course of business. Certain information and footnote disclosures normally included in the financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to those instructions. The year-end condensed balance sheet data was derived from audited financial statements but does not include all disclosures required by GAAP. The unaudited condensed consolidated financial statements, in the opinion of management, reflect all adjustments (consisting of normal recurring adjustments) necessary for a fair statement of the results for the interim periods ended September 30, 2019 and 2018 and the financial position at September 30, 2019 ; however, these results are not necessarily indicative of results which may be expected for the full year. The interim condensed consolidated financial statements, and notes thereto, should be read in conjunction with the audited consolidated financial statements for the year ended March 31, 2019 , and notes thereto, included in the Company’s annual report on Form 10 -K for the year ended March 31, 2019 filed with the Securities and Exchange Commission on June 5, 2019.
Liquidity, Policy [Policy Text Block]	Liquidity The Company has historically experienced recurring operating losses and as of September 30, 2019 , the Company had an accumulated deficit of $ 965.9 million. In addition, the Company has historically experienced recurring negative operating cash flows. At September 30, 2019 , the Company had cash, cash equivalents, and marketable securities of $ 62.8 million, with no outstanding debt other than ordinary trade payables. Marketable securities include certificate of deposits with maturities between twelve and twenty-four months. Cash used in operations for the six months ended September 30, 2019 was $ 10.5 million. On July 3, 2018, the Company and its wholly-owned subsidiaries Suzhou AMSC Superconductor Co. Ltd. (“AMSC China”) and AMSC Austria GMBH (“AMSC Austria”) entered into a settlement agreement (the “Settlement Agreement”) with Sinovel Wind Group Co., Ltd. (“Sinovel”). The Settlement Agreement settles the litigation and arbitration proceedings between the Company and Sinovel. Under the terms of the Settlement Agreement, Sinovel agreed to pay AMSC China an aggregate cash amount in Renminbi (“RMB”) equivalent to $57.5 million, consisting of two installments. Sinovel paid the first installment of the RMB equivalent of $32.5 million on July 4, 2018, which was repatriated to the Company during the nine months ended December 31, 2018 and paid the second installment of the RMB equivalent of $25.0 million on December 27, 2018. The Company’s fiscal 2018 results included the net gain received from the settlement with Sinovel of $52.7 million. On February 1, 2018, ASC Devens LLC (the “Seller”), a wholly-owned subsidiary of the Company, entered into a Purchase and Sale Agreement (the “PSA”) with 64 Jackson, LLC (the “Purchaser”) and Stewart Title Guaranty Company (“Escrow Agent”), to effectuate the sale of certain real property located at 64 Jackson Road, Devens, Massachusetts, including the building that had served as the Company’s headquarters (collectively, the “Property”), in exchange for total consideration of $23.0 million, composed of (i) cash consideration of $17.0 million, and (ii) a $6.0 million subordinated secured commercial promissory note payable to the Company (the “Seller Note”). Subsequently, the Seller, the Purchaser and Jackson 64 MGI, LLC (“Assignee”) entered into an Assignment of Purchase and Sale Agreement (the “Assignment Agreement”), pursuant to which the Purchaser assigned all of its rights and interests in the PSA to the Assignee and the Assignee agreed to assume all of the Purchaser’s obligations and liabilities under the PSA. The transaction closed on March 28, 2018, at which time the Company received, from the Assignee, cash consideration, net of certain agreed upon closing costs, of $16.9 million, and the Seller Note at an interest rate of 1.96%. The Seller Note was secured by a subordinated second mortgage on the Property and a subordinated second assignment of leases and rents. The Company received the first $3.0 million payment due pursuant to the Seller Note on March 28, 2019 and the second $3.0 million payment plus interest on May 23, 2019. In December 2015, the Company entered into a set of strategic agreements valued at approximately $210.0 million with Inox Wind Ltd. (“Inox” or “Inox Wind”), which includes a multi-year supply contract pursuant to which the Company will supply electrical control systems ("ECS") to Inox and a license agreement allowing Inox to manufacture a limited number of ECS. After Inox purchases the specified number of ECS required under the terms of the supply contract, Inox agreed that the Company will continue as Inox’s preferred supplier and Inox will be required to purchase from the Company a majority of its ECS requirements for an additional three -year period. Pursuant to these strategic agreements, Inox must forecast future purchase orders of sets of ECS which become firm orders three months prior to shipment, and Inox must post letters of credit before the Company will ship such orders. Inox is currently delinquent on its obligation to post letters of credit for sets of ECS that Inox forecasted to purchase under the terms of the supply contract. We cannot predict if and when Inox will post letters of credit consistent with the forecasted ECS quantities. Inox’s failure to post letters of credit and take delivery of forecasted ECS quantities would impact the Company’s revenues and liquidity. The Company believes that based on the information presented above and its quarterly management assessment, it has sufficient liquidity to fund its operations and capital expenditures for the next twelve months following the issuance of the financial statements for the six months ended September 30, 2019 . The Company’s liquidity is highly dependent on its ability to increase revenues, including its ability to collect revenues under its agreements with Inox, its ability to control its operating costs, and its ability to raise additional capital, if necessary. There can be no assurance that the Company will be able to continue to raise additional capital, on favorable terms or at all, from other sources or execute on any other means of improving liquidity described above.

Note 2 - Revenue Recognition (Tables)

6 Months Ended

Sep. 30, 2019

Notes Tables

Disaggregation of Revenue [Table Text Block]

	Three Months Ended September 30, 2019				Six Months Ended September 30, 2019
Product Line:	Grid		Wind		Grid		Wind
Equipment and systems	$	10,044	$	2,077	$	18,399	$	5,581
Services and technology development		1,445		446		2,946		856
Total	$	11,489	$	2,523	$	21,345	$	6,437

Region:
Americas	$	10,698	$	1	$	18,499	$	47
Asia Pacific		393		2,464		2,220		6,320
EMEA		398		58		626		70
Total	$	11,489	$	2,523	$	21,345	$	6,437

	Three Months Ended September 30, 2018				Six Months Ended September 30, 2018
Product Line:	Grid		Wind		Grid		Wind
Equipment and systems	$	5,503	$	7,219	$	12,957	$	10,711
Services and technology development		2,066		88		3,541		274
Total	$	7,569	$	7,307	$	16,498	$	10,985

Region:
Americas	$	5,052	$	24	$	12,548	$	47
Asia Pacific		2,308		7,278		3,115		10,873
EMEA		209		5		835		65
Total	$	7,569	$	7,307	$	16,498	$	10,985

Contract with Customer, Asset and Liability [Table Text Block]

	Unbilled Accounts Receivable			Deferred Program Costs			Contract Liabilities
Beginning balance as of March 31, 2019	$	2,213		$	318		$	15,519
Increases for costs incurred to fulfill performance obligations		—			2,153			—
Increase (decrease) due to customer billings		(2,926	)		—			19,340
Decrease due to cost recognition on completed performance obligations		—			(310	)		—
Increase (decrease) due to recognition of revenue based on transfer of control of performance obligations		4,711			—			(18,534	)
Other changes and FX impact		(4	)		(9	)		(313	)
Ending balance as of September 30, 2019	$	3,994		$	2,152		$	16,012

	Unbilled Accounts Receivable			Deferred Program Costs			Contract Liabilities
Beginning balance as of March 31, 2018	$	3,016		$	2,567		$	21,937
Impact of adoption of ASC 606		—			(1,599	)		(2,657	)
Increases for costs incurred to fulfill performance obligations		—			1,267			—
Increase (decrease) due to customer billings		(7,886	)		—			7,828
Decrease due to cost recognition on completed performance obligations		—			(1,033	)		—
Increase (decrease) due to recognition of revenue based on transfer of control of performance obligations		7,439			(9	)		(8,296	)
Other changes and FX impact		(19	)		24			(864	)
Ending balance as of September 30, 2018	$	2,550		$	1,217		$	17,948

Schedule of Revenue by Major Customers by Reporting Segments [Table Text Block]

		Three Months Ended						Six Months Ended
	Reportable	September 30,						September 30,
	Segment	2019			2018			2019			2018
Inox Wind Limited	Wind		<10%			45	%		17	%		36	%
Micron Technology	Grid		<10%			<10%			14	%		<10%
Vestas	Grid		<10%			11	%		<10%			23	%
Quanta Power	Grid		—	%		12	%		—	%		<10%
Hoffman Construction	Grid		25	%		—	%		12	%		—	%
M.J. Electric, LLC	Grid		25	%		—	%		13	%		—	%

Note 3 - Stock-based Compensation (Tables)

6 Months Ended

Sep. 30, 2019

Notes Tables

Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]

	Three Months Ended September 30,				Six Months Ended September 30,
	2019		2018		2019		2018
Cost of revenues	$	21	$	50	$	24	$	90
Research and development		92		70		103		121
Selling, general and administrative		283		705		519		1,399
Total	$	397	$	825	$	646	$	1,610

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

Three Months Ended September 30,

Six Months Ended September 30,

2019

2018

2019

2018

Expected volatility

N/A

66.5

N/A

Risk-free interest rate

N/A

1.8

N/A

Expected life (years)

N/A

5.91

N/A

Dividend yield

N/A

None

N/A

Note 4 - Computation of Net Loss per Common Share (Tables)

6 Months Ended

Sep. 30, 2019

Notes Tables

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

	Three Months Ended September 30,						Six Months Ended September 30,
	2019			2018			2019			2018
Numerator:
Net (loss) income	$	(825	)	$	22,558		$	(4,364	)	$	17,821
Less: decrease in fair value of warrants, net of income tax		(1,145	)		0			(4,092	)		0
Plus: change in fair value due to exercise of warrants		0			0			83			0
Net income (loss) - diluted	$	(1,970	)	$	22,558		$	(8,373	)	$	17,821
Denominator:
Weighted-average shares of common stock outstanding		21,678			21,252			21,538			21,126
Weighted-average shares subject to repurchase		(1,022	)		(939	)		(952	)		(886	)
Shares used in per-share calculation ― basic		20,656			20,313			20,586			20,240
Common stock awards		0			268			0			320
Common stock warrants		67			0			150			0
Shares used in per-share calculation ― diluted		20,723			20,581			20,736			20,560
Net (loss) income per share ― basic	$	(0.04	)	$	1.11		$	(0.21	)	$	0.88
Net (loss) income per share ― diluted	$	(0.10	)	$	1.10		$	(0.40	)	$	0.87

Note 6 - Fair Value Measurements (Tables)

6 Months Ended

Sep. 30, 2019

Notes Tables

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

	Total Carrying Value		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
September 30, 2019:
Assets:
Cash equivalents	$	49,034	$	49,034	$	—	$	—
Marketable securities	$	10,000	$	10,000	$	—	$	—
Derivative liabilities:
Warrants	$	556	$	—	$	—	$	556

	Total Carrying Value		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
March 31, 2019:
Assets:
Cash equivalents	$	41,839	$	41,839	$	—	$	—
Derivative liabilities:
Warrants	$	4,942	$	—	$	—	$	4,942

Fair Value, Liabilities Measured on Recurring Basis [Table Text Block]

	Warrants
April 1, 2019	$	4,942
Mark to market adjustment		(4,092	)
Warrant exercise		(294	)
Balance at September 30, 2019	$	556

	Warrants
April 1, 2018	$	1,217
Mark to market adjustment		182
Balance at September 30, 2018	$	1,399

Note 8 - Inventory (Tables)

6 Months Ended

Sep. 30, 2019

Notes Tables

Schedule of Inventory, Current [Table Text Block]

	September 30, 2019		March 31, 2019
Raw materials	$	7,421	$	5,474
Work-in-process		1,943		1,922
Finished goods		3,981		4,405
Deferred program costs		2,152		318
Net inventory	$	15,497	$	12,119

Note 11 - Accounts Payable and Accrued Expenses (Tables)

6 Months Ended

Sep. 30, 2019

Notes Tables

Schedule of Accounts Payable and Accrued Liabilities [Table Text Block]

	September 30, 2019		March 31, 2019
Accounts payable	$	6,164	$	2,939
Accrued inventories in-transit		603		244
Accrued other miscellaneous expenses		1,772		1,759
Advanced deposits		1,771		631
Accrued compensation		3,730		5,404
Income taxes payable		3,043		3,363
Accrued product warranty		1,641		1,545
Total	$	18,724	$	15,885

Schedule of Product Warranty Liability [Table Text Block]

	Three Months Ended September 30,						Six Months Ended September 30,
	2019			2018			2019			2018
Balance at beginning of period	$	1,606		$	1,752		$	1,545		$	1,769
Change in accruals for warranties during the period		71			213			156			317
Settlements during the period		(36	)		(205	)		(60	)		(326	)
Balance at end of period	$	1,641		$	1,760		$	1,641		$	1,760

Note 13 - Warrants and Derivative Liabilities (Tables)

6 Months Ended

Sep. 30, 2019

Notes Tables

Fair Value Option, Disclosures [Table Text Block]

	September 30,			June 30,
Fiscal Year 2019		2019			2019
Risk-free interest rate		1.90	%		2.11	%
Expected annual dividend yield		—			—
Expected volatility		62.84	%		60.58	%
Term (years)		0.12			0.37
Fair value	$0.6 million			$1.7 million

	March 31,	December 31,	September 30,	June 30,	March 31,
Fiscal Year 2018	2019	2018	2018	2018	2018
Risk-free interest rate	2.43%	2.61%	2.62%	2.40%	2.20%
Expected annual dividend yield	—	—	—	—	—
Expected volatility	75.61%	70.29%	63.66%	67.40%	65.86%
Term (years)	0.62	0.87	1.12	1.37	1.62
Fair value	$4.6 million	$3.6 million	$1.3 million	$1.6 million	$1.1 million

Note 14 - Leases (Tables)

6 Months Ended

Sep. 30, 2019

Notes Tables

Assets And Liabilities Lessee [Table Text Block]

	September 30, 2019
Operating Leases:
Right-of-use assets	$	3,607
Total right-of-use assets		3,607

Lease liabilities - ST	$	424
Lease liabilities - LT		3,240
Total operating lease liabilities		3,664

Weighted-average remaining lease term		7.31 years
Weighted-average discount rate		7.07	%

Lease, Cost [Table Text Block]

	Three Months Ended		Six Months Ended
	September 30, 2019		September 30, 2019
Operating Lease:
Operating lease costs - fixed	$	178	$	356
Operating lease costs - variable		27		46
Short-term lease costs		176		214
Total lease costs		381		616

Lessee, Operating Lease, Liability, Maturity [Table Text Block]

	Operating Leases
Year ended March 31,
2020	$	331
2021		670
2022		650
2023		624
2024		562
Thereafter		1,896
Total minimum lease payments		4,733
Less: interest		(1,069	)
Present value of lease liabilities		3,664

Accounting Standards Update 2016-02 [Member]

Notes Tables

Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block]

	March 31, 2019		ASC 842 Adjustment		April 1, 2019
Operating Leases:
Right of use asset	$	—	$	3,795	$	3,795
Total operating lease right-of-use asset		—		3,795		3,795

Operating lease liabilities – ST	$	—	$	309	$	309
Operating lease liabilities – LT		—		3,512		3,512
Total operating lease liabilities		—		3,821		3,821

Weighted-average remaining lease term					7.69 years
Weighted-average discount rate						7.06	%

Note 17 - Business Segments (Tables)

6 Months Ended

Sep. 30, 2019

Notes Tables

Schedule of Segment Reporting Information, by Segment [Table Text Block]

	Three Months Ended September 30,				Six Months Ended September 30,
	2019		2018		2019		2018
Revenues:
Grid	$	11,489	$	7,569	$	21,345	$	16,498
Wind		2,523		7,307		6,437		10,985
Total	$	14,012	$	14,876	$	27,782	$	27,483

	Three Months Ended September 30,						Six Months Ended September 30,
	2019			2018			2019			2018
Operating (loss) income:
Grid	$	(1,324	)	$	(2,870	)	$	(5,988	)	$	(5,537	)
Wind		(2,398	)		28,515			(3,721	)		27,150
Unallocated corporate expenses		(397	)		(918	)		(646	)		(2,013	)
Total	$	(4,119	)	$	24,727		$	(10,355	)	$	19,600

Reconciliation of Assets from Segment to Consolidated [Table Text Block]

	September 30, 2019		March 31, 2019
Grid	$	34,479	$	31,075
Wind		12,474		8,167
Corporate assets		70,490		80,088
Total	$	117,443	$	119,330

Note 1 - Nature of the Business and Operations and Liquidity (Details Textual) $ in Thousands						1 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
	May 23, 2019 USD ($)	Mar. 28, 2019 USD ($)	Jul. 04, 2018 USD ($)	Jul. 03, 2018 USD ($)	Feb. 01, 2018 USD ($)	Dec. 31, 2015 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Mar. 31, 2019 USD ($)	Dec. 27, 2018 USD ($)	Mar. 28, 2018 USD ($)
Retained Earnings (Accumulated Deficit), Ending Balance							$ (965,903)		$ (965,903)		$ (961,539)
Cash, Cash Equivalents, and Marketable Securities							62,800		62,800
Net Cash Provided by (Used in) Operating Activities, Total									(10,485)	$ 23,595
Gain (Loss) Related to Litigation Settlement, Total							$ 0	$ 28,720	$ 0	$ 28,720
Sinovel [Member]
Litigation Settlement, Amount Awarded from Other Party				$ 57,500
Litigation Settlement, Number of Installments				2
Proceeds from Legal Settlements			$ 32,500
Litigation Receivable												$ 25,000
Gain (Loss) Related to Litigation Settlement, Total											$ 52,700
64 Jackson, LLC [Member]
Purchase and Sale Agreement, Total Consideration					$ 23,000
Purchase and Sale Agreement, Proceeds from Sale of Property, Plant and Equipment					17,000
Financing Receivable, after Allowance for Credit Loss, Noncurrent, Total					$ 6,000
Purchase and Sale Agreement, Proceeds from Sale of Property, Plant and Equipment, Net													$ 16,900
Notes Receivable, Stated Interest Rate											1.96%		1.96%
Proceeds from Collection of Notes Receivable	$ 3,000	$ 3,000
Inox Wind Limited [Member]
Supply Agreement, Aggregate Value						$ 210,000
Supply Commitment, Extension Period						3 years
Certificates of Deposit [Member] \| Minimum [Member]
Debt Securities, Available-for-sale, Term							1 year		1 year
Certificates of Deposit [Member] \| Maximum [Member]
Debt Securities, Available-for-sale, Term							2 years		2 years

Note 2 - Revenue Recognition 1 (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenue, Performance Obligation Satisfied, Revenue Recognized, Percentage	77.00%		77.00%
Minimum [Member]
Warranty Period			1 year
Contract with Customer, Payment Term			30 days
Maximum [Member]
Warranty Period			2 years
Extended Service Warranty, Term			4 years
Contract with Customer, Payment Term			60 days
Grant [Member]
Revenues, Total	$ 700	$ 0	$ 1,100	$ 0

Note 2 - Revenue Recognition 2 (Details Textual) $ in Thousands	Sep. 30, 2019 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Amount	$ 50,400
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-10-01
Revenue, Remaining Performance Obligation, Amount	$ 7,200
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-10-01 \| Minimum [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year 30 days
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-10-01 \| Maximum [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	5 years

Note 2 - Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues	$ 14,012	$ 14,876	$ 27,782	$ 27,483
Grid [Member]
Revenues	11,489	7,569	21,345	16,498
Grid [Member] \| Americas [Member]
Revenues	10,698	5,052	18,499	12,548
Grid [Member] \| Asia Pacific [Member]
Revenues	393	2,308	2,220	3,115
Grid [Member] \| EMEA [Member]
Revenues	398	209	626	835
Wind [Member]
Revenues	2,523	7,307	6,437	10,985
Wind [Member] \| Americas [Member]
Revenues	1	24	47	47
Wind [Member] \| Asia Pacific [Member]
Revenues	2,464	7,278	6,320	10,873
Wind [Member] \| EMEA [Member]
Revenues	58	5	70	65
Equipment and Systems [Member] \| Grid [Member]
Revenues	10,044	5,503	18,399	12,957
Equipment and Systems [Member] \| Wind [Member]
Revenues	2,077	7,219	5,581	10,711
Services and Technology Development [Member] \| Grid [Member]
Revenues	1,445	2,066	2,946	3,541
Services and Technology Development [Member] \| Wind [Member]
Revenues	$ 446	$ 88	$ 856	$ 274

Note 2 - Revenue Recognition - Contract Assets and Liabilities (Details) - USD ($) $ in Thousands	6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Unbilled AR, beginning balance	$ 2,213	$ 3,016
Deferred Program Costs, beginning balance	318	2,567
Contract Liabilities, beginning balance	15,519	21,937
Deferred Program Costs, increases for costs incurred to fulfill performance obligations	2,153	1,267
Unbilled AR, increase (decrease) due to customer billings	(2,926)	(7,886)
Increase (decrease) due to customer billings	19,340	7,828
Unbilled AR,Decrease due to cost recognition on completed performance obligations
Deferred Program Costs, decrease due to cost recognition on completed performance obligations	(310)	(1,033)
Unbilled AR, increase (decrease) due to recognition of revenue based on transfer of control of performance obligations	4,711	7,439
Deferred Program Costs, increase (decrease) due to recognition of revenue based on transfer of control of performance obligations		(9)
Increase (decrease) due to recognition of revenue based on transfer of control of performance obligations	(18,534)	(8,296)
Unbilled AR, other changes and FX impact	(4)	(19)
Deferred Program Costs, other changes and FX impact	(9)	24
Other changes and FX impact	(313)	(864)
Unbilled AR, impact of adoption of ASC 606
Deferred Program Costs, impact of adoption of ASC 606		(1,599)
Contract Liabilities, impact of adoption of ASC 606		(2,657)
Unbilled AR, ending balance	3,994	2,550
Deferred Program Costs, ending balance	2,152	1,217
Contract Liabilities, ending balance	$ 16,012	$ 17,948

Note 2 - Revenue Recognition - Revenues By Major Customers (Details) - Customer Concentration Risk [Member] - Revenue Benchmark [Member]	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Wind [Member] \| Inox Wind Limited [Member]
Concentration risk percentage		45.00%	17.00%	36.00%
Grid [Member] \| Micron Technology [Member]
Concentration risk percentage			14.00%
Grid [Member] \| Vestas WTG Mexico [Member]
Concentration risk percentage		11.00%		23.00%
Grid [Member] \| Quanta Power [Member]
Concentration risk percentage	0.00%	12.00%	0.00%
Grid [Member] \| Hoffman Construction [Member]
Concentration risk percentage	25.00%	0.00%	12.00%	0.00%
Grid [Member] \| M.J. Electric, LLC [Member]
Concentration risk percentage	25.00%	0.00%	13.00%	0.00%

Note 3 - Stock-based Compensation (Details Textual) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	0	0	5,939	0
Restricted Stock [Member]
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture, Total			170,500	413,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total	$ 3.1		$ 3.1
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition			1 year 146 days
Restricted Stock [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period			2 years
Restricted Stock [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period			3 years
Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	2 years		2 years
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total	$ 0.1		$ 0.1
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition			1 year 255 days
Common Stock [Member]
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture, Total			13,174	37,075

Note 3 - Stock-based Compensation - Stock-based Compensation Expense By Financial Statement Line Item (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Total stock-based compensation expense	$ 397	$ 825	$ 646	$ 1,610
Cost of Sales [Member]
Total stock-based compensation expense	21	50	24	90
Research and Development Expense [Member]
Total stock-based compensation expense	92	70	103	121
Selling, General and Administrative Expenses [Member]
Total stock-based compensation expense	$ 283	$ 705	$ 519	$ 1,399

Note 3 - Stock-based Compensation - Black Scholes Valuation (Details)	6 Months Ended
	Sep. 30, 2019
Expected volatility	66.50%
Risk-free interest rate	1.80%
Expected life (years) (Year)	5 years 332 days
Dividend yield	0.00%

Note 4 - Computation of Net Loss per Common Share (Details Textual) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	200,000	1,600,000	1,000,000	1,400,000
Incremental Common Shares Attributable to Dilutive Effect of Call Options and Warrants	67,000	0	150,000	0
Fair Value Adjustment of Warrants	$ (1,145)		$ (4,092)	$ 182
Hudson Warrant [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	818,181		818,181
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 7.81		$ 7.81
Average Common Stock Price	$ 8.50		$ 9.56
Incremental Common Shares Attributable to Dilutive Effect of Call Options and Warrants	66,638		150,025
Fair Value Adjustment of Warrants	$ (1,100)		$ (4,100)
Share-based Payment Arrangement, Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount		300,000	200,000	200,000
Warrant [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	800,000	900,000		900,000
Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount		400,000		300,000

Note 4 - Computation of Net Loss per Common Share - Reconciliation of Numerators and Denominators of EPS Calculation (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Numerator:
Net (loss) income	$ (825)	$ 22,558	$ (4,364)	$ 17,821
Fair Value Adjustment of Warrants	(1,145)		(4,092)	182
Plus: change in fair value due to exercise of warrants	0	0	83	0
Net income (loss) - diluted	$ (1,970)	$ 22,558	$ (8,373)	$ 17,821
Denominator:
Weighted-average shares of common stock outstanding (in shares)	21,678	21,252	21,538	21,126
Weighted-average shares subject to repurchase (in shares)	(1,022)	(939)	(952)	(886)
Shares used in per-share calculation - basic (in shares)	20,656	20,313	20,586	20,240
Common stock awards (in shares)	0	268	0	320
Common stock warrants (in shares)	67	0	150	0
Shares used in per-share calculation - diluted (in shares)	20,723	20,581	20,736	20,560
Net (loss) income per share - basic (in dollars per share)	$ (0.04)	$ 1.11	$ (0.21)	$ 0.88
Net (loss) income per share - diluted (in dollars per share)	$ (0.10)	$ 1.10	$ (0.40)	$ 0.87

Note 6 - Fair Value Measurements - Assets and Liabilities Carried at Fair Value on a Recurring Basis (Details) - USD ($)	Sep. 30, 2019	Mar. 31, 2019
Derivative liabilities	$ 556,000	$ 4,942,000
Reported Value Measurement [Member] \| Fair Value, Recurring [Member]
Cash equivalents	49,034,000	41,839,000
Marketable securities	10,000
Reported Value Measurement [Member] \| Fair Value, Recurring [Member] \| Warrant [Member]
Derivative liabilities	556,000	4,942,000
Reported Value Measurement [Member] \| Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Cash equivalents	49,034,000	41,839,000
Marketable securities	10,000
Derivative liabilities	0	0
Reported Value Measurement [Member] \| Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Cash equivalents	0
Marketable securities
Derivative liabilities	0	0
Reported Value Measurement [Member] \| Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Cash equivalents	0
Marketable securities
Derivative liabilities	$ 556,000	$ 4,942,000

Note 6 - Fair Value Measurements - Liabilities Measured at Fair Value on a Recurring Basis (Details) - Warrant Liability [Member] - USD ($) $ in Thousands	6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Beginning balance	$ 4,942	$ 1,217
Mark to market adjustment	(4,092)	182
Warrant exercise	(294)
Ending balance	$ 556	$ 1,399

Note 7 - Accounts Receivable - Summary of Accounts Receivable (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Mar. 31, 2019
Accounts receivable (billed)	$ 6,079	$ 5,642
Accounts receivable (unbilled)	3,994	2,213
Accounts receivable, net	$ 10,073	$ 7,855

Note 8 - Inventory - Summary of Net Inventory (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Mar. 31, 2019
Raw materials	$ 7,421	$ 5,474
Work-in-process	1,943	1,922
Finished goods	3,981	4,405
Deferred program costs	2,152	318
Net inventory	$ 15,497	$ 12,119

Note 9 - Note Receivable (Details Textual) - 64 Jackson, LLC [Member] $ in Millions		6 Months Ended
	Feb. 01, 2018 USD ($)	Sep. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Mar. 28, 2018
Purchase and Sale Agreement, Total Consideration	$ 23.0
Security Deposit	1.0
Financing Receivable, after Allowance for Credit Loss, Noncurrent, Total	$ 6.0
Notes and Loans Receivable, Number of Installments			2
Notes and Loans Receivable, Installment Amount			$ 3.0
Notes Receivable, Stated Interest Rate			1.96%	1.96%
Notes Receivable, Fair Value Disclosure		$ 5.7
Note Receivable Discount Rate		6.00%
Notes and Loans Receivable, Noncurrent Portion of Unamortized Debt Discount		$ 0.3
Deferred Gain on Sale of Property		$ 0.1

Note 9 - Note Receivable - Summary of Note Receivable (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Mar. 31, 2019
Note receivable, current		$ 3,000
Note receivable discount		(112)
Total current note receivable		$ 2,888

Note 10 - Property, Plant and Equipment - Cost and Accumulated Depreciation of Property and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Mar. 31, 2019
Property, plant and equipment, gross	$ 50,585	$ 49,532
Less accumulated depreciation	(41,975)	(40,560)
Property, plant and equipment, net	8,610	8,972
Construction in Progress [Member]
Property, plant and equipment, gross	2,223	603
Equipment and Software [Member]
Property, plant and equipment, gross	45,127	45,705
Furniture and Fixtures [Member]
Property, plant and equipment, gross	1,259	1,269
Leasehold Improvements [Member]
Property, plant and equipment, gross	$ 1,976	$ 1,955

Note 11 - Accounts Payable and Accrued Expenses - Summary of Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Mar. 31, 2019
Accounts payable	$ 6,164	$ 2,939
Accrued inventories in-transit	603	244
Accrued other miscellaneous expenses	1,772	1,759
Advanced deposits	1,771	631
Accrued compensation	3,730	5,404
Income taxes payable	3,043	3,363
Accrued product warranty	1,641	1,545
Total	$ 18,724	$ 15,885

Note 11 - Accounts Payable and Accrued Expenses - Product Warranty Activity (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Balance at beginning of period	$ 1,606	$ 1,752	$ 1,545	$ 1,769
Change in accruals for warranties during the period	71	213	156	317
Settlements during the period	(36)	(205)	(60)	(326)
Balance at end of period	$ 1,641	$ 1,760	$ 1,641	$ 1,760

Note 12 - Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Mar. 31, 2019
Income Tax Expense (Benefit), Total	$ (294)	$ 3,008	$ (83)	$ 2,964
Liability for Uncertainty in Income Taxes, Current	$ 0		$ 0
Unrecognized Tax Benefits, Ending Balance					$ 0

Note 13 - Warrants and Derivative Liabilities (Details Textual) - USD ($) $ / shares in Units, $ in Thousands			3 Months Ended		6 Months Ended
	Apr. 17, 2019	Dec. 19, 2014	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Mar. 31, 2019	Nov. 13, 2014
Gain (Loss) in Change of Fair Value of Derivative Instruments and Warrants			$ 1,145	$ 282	$ 4,092	$ (182)
Hercules Warrants [Member]
Gain (Loss) on Decrease Fair Value Upon Exercise of Warrant					$ 100
November 2014 Warrant [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights								$ 7.81
Common Unit, Issued								909,090
Common Shares Per Unit								1
Class of Warrant or Right, Number of Warrants to Purchase One Share of Stock								0.9
Class of Warrant or Right, Number of Securities Called by Warrants or Rights								818,181
Warrants and Rights Outstanding, Maturity Date								Nov. 13, 2019
Hercules Technology Growth Capital [Member]
Stock Issued During Period, Shares, Warrant Exercised	22,821
Secured Debt [Member] \| Hercules Technology Growth Capital [Member] \| Hercules Warrants [Member]
Purchase Commitment, Issuance of Warrants, Shares of Common Stock		58,823
Class of Warrant or Right, Exercise Price of Warrants or Rights			$ 7.85		$ 7.85
Derivative, Fair Value, Net, Total							$ 400

Note 13 - Warrants and Derivative Liabilities - Summary of the Key Assumptions Used to Calculate Fair Value of Warrants (Details) $ in Millions	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($) yr	Dec. 31, 2018 USD ($) yr	Sep. 30, 2018 USD ($) yr	Jun. 30, 2018 USD ($) yr	Mar. 31, 2018 USD ($) yr
Fair value	$ 0.6	$ 1.7	$ 4.6	$ 3.6	$ 1.3	$ 1.6	$ 1.1
Measurement Input, Risk Free Interest Rate [Member]
Warrants and Rights Outstanding, Measurement Input	0.019	0.0211	0.0243	0.0261	0.0262	0.024	0.022
Measurement Input, Expected Dividend Rate [Member]
Warrants and Rights Outstanding, Measurement Input
Measurement Input, Price Volatility [Member]
Warrants and Rights Outstanding, Measurement Input	0.6284	0.6058	0.7561	0.7029	0.6366	0.674	0.6586
Measurement Input, Expected Term [Member]
Warrants and Rights Outstanding, Measurement Input	0.12	0.37	0.62	0.87	1.12	1.37	1.62

Note 14 - Leases (Details Textual) - USD ($) $ in Thousands	Apr. 01, 2019	Sep. 30, 2019	Mar. 31, 2019
Operating Lease, Right-of-Use Asset	$ 3,795	$ 3,607	$ 0
Operating Lease, Liability, Total	3,821	$ 3,664
Maximum [Member]
Lessee, Operating Lease, Renewal Term		5 years
Accounting Standards Update 2016-02 [Member]
Operating Lease, Right-of-Use Asset	3,800		3,795
Operating Lease, Liability, Total	3,800		$ 3,821
Operating Lease, Impairment Loss	$ 0

Note 14 - Leases - Adoption of ASC 842 (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Apr. 01, 2019	Mar. 31, 2019
Right-of-use asset	$ 3,607	$ 3,795	$ 0
Lease liability, current portion	424	309	0
Lease liability, long term portion	3,240	3,512	$ 0
Total operating lease liabilities	$ 3,664	$ 3,821
Weighted-average remaining lease term (Year)	7 years 113 days	7 years 251 days
Weighted-average discount rate	7.07%	7.06%
Accounting Standards Update 2016-02 [Member]
Right-of-use asset		$ 3,800	$ 3,795
Lease liability, current portion			309
Lease liability, long term portion			3,512
Total operating lease liabilities		$ 3,800	$ 3,821
Weighted-average remaining lease term (Year)
Weighted-average discount rate
Previous Accounting Guidance [Member]
Right-of-use asset
Lease liability, current portion
Lease liability, long term portion
Total operating lease liabilities

Note 14 - Leases - Operating Lease Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Apr. 01, 2019	Mar. 31, 2019
Right-of-use asset	$ 3,607	$ 3,795	$ 0
Lease liability, current portion	424	309	0
Lease liability, long term portion	3,240	3,512	$ 0
Total operating lease liabilities	$ 3,664	$ 3,821
Weighted-average remaining lease term (Year)	7 years 113 days	7 years 251 days
Weighted-average discount rate	7.07%	7.06%

Note 14 - Leases - Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Operating lease costs - fixed	$ 178	$ 356
Operating lease costs - variable	27	46
Short-term lease costs	176	214
Total lease costs	$ 381	$ 616

Note 14 - Leases - Minimum Future Lease Obligation (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Apr. 01, 2019
2020	$ 331
2021	670
2022	650
2023	624
2024	562
Thereafter	1,896
Total minimum lease payments	4,733
Less: interest	(1,069)
Total operating lease liabilities	$ 3,664	$ 3,821

Note 15 - Commitments and Contingencies (Details Textual) - USD ($) $ in Thousands	Sep. 30, 2019	Jul. 01, 2019	Mar. 31, 2019
Restricted Cash and Cash Equivalents, Noncurrent, Total	$ 5,736		$ 715
Letter of Credit [Member]
Escrow Deposit		$ 5,000

Note 16 - Restructuring - Restructuring Charges and Cash Payments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Accrued restructuring balance, beginning				$ 435
Restructuring Charges, Total	$ 0	$ 93	$ 0	403
Cash payments				(749)
Accrued restructuring balance, ending		89		89
Employee Severance Pay and Benefits [Member]
Accrued restructuring balance, beginning				262
Restructuring Charges, Total
Cash payments				(173)
Accrued restructuring balance, ending		89		89
Facility Exit and Relocation Costs [Member]
Accrued restructuring balance, beginning				173
Restructuring Charges, Total				403
Cash payments				(576)
Accrued restructuring balance, ending

Note 17 - Business Segments (Details Textual) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) MWh	Sep. 30, 2018 USD ($)
Number of Reportable Segments			2
Share-based Payment Arrangement, Expense	$ 397	$ 825	$ 646	$ 1,610
Restructuring Charges, Total	0	93	0	403
Corporate, Non-Segment [Member]
Share-based Payment Arrangement, Expense	$ 400	800	$ 600	1,600
Restructuring Charges, Total		$ 100		$ 400
Minimum [Member]
Power of Wind Turbines \| MWh			2

Note 17 - Business Segments - Operating Results for Business Segments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues	$ 14,012	$ 14,876	$ 27,782	$ 27,483
Operating profit (loss)	(4,119)	24,727	(10,355)	19,600
Corporate, Non-Segment [Member]
Operating profit (loss)	(397)	(918)	(646)	(2,013)
Grid [Member]
Revenues	11,489	7,569	21,345	16,498
Grid [Member] \| Operating Segments [Member]
Operating profit (loss)	(1,324)	(2,870)	(5,988)	(5,537)
Wind [Member]
Revenues	2,523	7,307	6,437	10,985
Wind [Member] \| Operating Segments [Member]
Operating profit (loss)	$ (2,398)	$ 28,515	$ (3,721)	$ 27,150

Note 17 - Business Segments - Total Business Segments Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Mar. 31, 2019
Total assets	$ 117,443	$ 119,330
Operating Segments [Member] \| Grid [Member]
Total assets	34,479	31,075
Operating Segments [Member] \| Wind [Member]
Total assets	12,474	8,167
Corporate, Non-Segment [Member]
Total assets	$ 70,490	$ 80,088

Note 5 - Goodwill	6 Months Ended
Note 5 - Goodwill	Sep. 30, 2019
Notes to Financial Statements
Goodwill Disclosure [Text Block]	5. Goodwill The Company did not identify any triggering events in the three and six months ended September 30, 2019 , that would require interim impairment testing of goodwill.

Note 19 - Subsequent Events	6 Months Ended
Note 19 - Subsequent Events	Sep. 30, 2019
Notes to Financial Statements
Subsequent Events [Text Block]	19. Subsequent Events The Company has performed an evaluation of subsequent events through the time of filing this Quarterly Report on Form 10 -Q with the SEC and has determined that there are no such events to report.

Note 11 - Accounts Payable and Accrued Expenses (Details Textual)	6 Months Ended
	Sep. 30, 2019
Minimum [Member]
Extended Warranty Trigger Period	1 year
Maximum [Member]
Extended Warranty Trigger Period	3 years