8.  Stock-Based Compensation

The following table summarizes, by condensed consolidated statements of operations line item, stock-based compensation expense (in thousands):

Stock Plans

2000 Equity Incentive Plan and 2017 Equity Incentive Plan

In June 2000, the Company adopted the 2000 Equity Incentive Plan (“2000 Plan”). The 2000 Plan provides for a total maximum aggregate number of shares which may be issued of 184,900 shares. In June 2017, the Company’s Board adopted the Capstone Turbine Corporation 2017 Equity Incentive Plan (the “2017 Plan”), which was approved by the stockholders at the Company’s 2017 annual meeting of stockholders on August 31, 2017 (the “2017 Annual Meeting”). The 2017 Plan provides for awards of up to 300,000 shares of Common Stock. The 2017 Plan is administered by the Compensation Committee designated by the Board (the “Compensation Committee”). The Compensation Committee’s authority includes determining the number of incentive awards and vesting provisions. On June 5, 2018, the Company’s Board of Directors adopted an amendment of the 2017 Plan to increase the aggregate number of shares of Common Stock authorized for issuance under the 2017 Plan by 300,000 shares of Common Stock. The amendment of the 2017 Plan was approved by the Company’s stockholders at the 2018 annual meeting of stockholders on August 30, 2018.

On August 29, 2019, at the Company’s 2019 annual meeting, the Company’s stockholders approved another amendment to the 2017 Plan to increase the aggregate number of shares authorized for issuance under the 2017 Plan by 300,000 shares to 900,000 shares of Common Stock.

On August 27, 2020, at the Company’s 2020 annual meeting, the Company’s stockholders approved another amendment to the 2017 Plan to increase the aggregate number of shares authorized for issuance under the 2017 Plan by 500,000 shares to 1,400,000 shares of Common Stock.  As of December 31, 2020, there were 687,432 shares available for future grants under the 2017 Plan.

Stock Options

The Company issued stock options under the 2000 Plan and can issue stock options under the 2017 Plan to employees, non-employee directors and consultants that vest and become exercisable over a four-year period and expire 10 years after the grant date. The Company uses a Black-Scholes valuation model to estimate the fair value of the options at the grant date, and compensation cost is recorded on a straight-line basis over the vesting period. All options are subject to the following vesting provisions: one-fourth vest one year after the issuance date and 1/48th vest on the first day of each full month thereafter, so that all options will be vested on the first day of the 48th month after the grant date. The following table summarizes information relating to the Company’s stock option activity during the nine months ended December 31, 2020:

Black-Scholes Model Valuation Assumptions

There were no stock options granted and no expense associated with stock options during the three and nine months ended December 31, 2020 and 2019. There were no unvested stock option awards as of December 31, 2020.

Restricted Stock Units and Performance Restricted Stock Units

The Company issued restricted stock units under the 2000 Plan and issued restricted stock units under the 2017 Plan to employees, non-employee directors and consultants. The restricted stock units are valued based on the closing price of the Company’s Common Stock on the date of issuance, and compensation cost is recorded on a straight-line basis over the vesting period. The restricted stock units issued to employees vest over a period of two,  three or four years. For restricted stock units with two year vesting, 100% vests on the second year anniversary. For restricted stock units with three year vesting, one-third vest annually beginning one year after the issuance date. For restricted stock units with four year vesting, one-fourth vest annually beginning one year after the issuance date. The restricted stock units issued to non-employee directors vest one year after the issuance date. The following table summarizes restricted stock unit and performance restricted stock unit (“PRSU”) activity during the nine months ended December 31, 2020:

The following table provides additional information on restricted stock units and performance restricted stock units:

As of December 31, 2020, there was approximately $1.4 million of total compensation cost related to unvested restricted stock units that is expected to be recognized as expense over a weighted average period of 2.1 years.

The Company’s PRSU activity is included in the above restricted stock units tables. The PRSU program has a two-year or three-year performance measurement period. The performance measurement period begins on April 1 of the first fiscal year and end on March 31 of the second fiscal year or the third fiscal year after the grant date. The program is intended to have overlapping performance measurement periods (e.g., a new three-year cycle begins each year on April 1), subject to Compensation Committee approval. At the end of each performance measurement period, the Compensation Committee will determine the achievement against the performance objectives.

There were no PRSUs granted during the nine months ended December 31, 2020. During the nine months ended December 31, 2019, the Company granted 30,139 PRSUs with a three-year performance measurement period and the criteria measured by the Company’s cash flow from operations and aftermarket sales absorption. The target PRSU awards for each participant, will be paid upon achievement of the target level of performance for cash flow from operations and aftermarket sale absorption, taking into account the applicable weighting for the individual metric. Achievement of a performance goal at the threshold level will result in a payment that is 50% of the target PRSU award. Achievement of a performance goal at the maximum level will result in a payment that is 150% of the target PRSU award. The Compensation Committee will use an interpolation table that weights performance between levels for determining the portion of the Target PRSU that is earned.

The weighted average per share grant date fair value of PRSUs granted during the nine months ended December 31, 2019 was $8.90. Based on the Company’s assessment as of December 31, 2020, the Company will not meet the threshold of the performance measurements, and as a result, no compensation expense was recorded during the nine months ended December 31, 2020. Compensation expense is recognized over the corresponding requisite service period and will be adjusted in subsequent reporting periods if the Company’s assessment of the probable level of achievement of the performance goals change. The Company will continue to assess the likelihood of the PRSU threshold being met until the end of the applicable performance period.

Employee Stock Purchase Plan

In June 2000, the Company adopted the Employee Stock Purchase Plan (the “ESPP”). The ESPP provides for the granting of rights to purchase Common Stock to regular full and part-time employees or officers of the Company and its subsidiaries. In June 2017, the Board unanimously approved an amendment and restatement to the ESPP which was approved by the stockholders at the Company’s annual meeting of stockholders on August 31, 2017. Prior to the amendment, 7,000 shares of the Company’s Common Stock had been reserved for issuance. As amended, the ESPP continued by its terms and the number of shares of the Company’s Common Stock available increased by 50,000 shares which reserved for issuance a total of 57,000 shares of common stock. Under the ESPP, shares of the Company’s Common Stock are issued upon exercise of the purchase rights. The ESPP terminated as of December 31, 2020. The maximum amount that an employee can contribute during a purchase right period is $25,000 or 15% of the employee’s regular compensation. Under the ESPP, the exercise price of a purchase right is 95% of the fair market value of such shares on the last day of the purchase right period. The fair market value of the stock is its closing price as reported on the Nasdaq Capital Market on the day in question.

Stockholder Rights Plan

On May 6, 2019, the Board declared a dividend of one right (a “New Right”) for each of the Company’s issued and outstanding shares of Common Stock. The dividend was paid to the stockholders of record at the close of business on May 16, 2019 (the “Record Date”). Each New Right entitles the registered holder, subject to the terms of the NOL Rights Agreement (as defined below), to purchase from the Company one one-thousandth of a share of the Company’s Series B Junior Participating Preferred Stock (the “Preferred Stock”) at a price of $5.22 (the “Exercise Price”), subject to certain adjustments. The description and terms of the New Rights are set forth in the Rights Agreement dated as of May 6, 2019 (the “NOL Rights Agreement”) between the Company and Broadridge Financial Solutions, Inc., as Rights Agent (the “Rights Agent”).

The NOL Rights Agreement replaced the Company’s Rights Agreement, dated May 6, 2016, by and between the Company and Broadridge Financial Solutions, Inc., as successor-in-interest to Computershare Inc., as rights agent (the “Original Rights Agreement”). The Original Rights Agreement, and the rights thereunder to purchase fractional shares of Preferred Stock, expired at 5:00 p.m., New York City time, on May 6, 2019 and the NOL Rights Agreement was entered into immediately thereafter.

The purpose of the NOL Rights Agreement is to diminish the risk that the Company’s ability to use its net operating losses and certain other tax assets (collectively, “Tax Benefits”) to reduce potential future federal income tax obligations would become subject to limitations by reason of the Company’s experiencing an “ownership change,” as defined in Section 382 of the Internal Revenue Code of 1986, as amended (the “Tax Code”). A company generally experiences such an ownership change if the percentage of its stock owned by its “5-percent shareholders,” as defined in Section 382 of the Tax Code, increases by more than 50 percentage points over a rolling three-year period. The NOL Rights Agreement is designed to reduce the likelihood that the Company will experience an ownership change under Section 382 of the Tax Code by (i) discouraging any person or group from becoming a 4.9% or greater shareholder and (ii) discouraging any existing 4.9% or greater shareholder from acquiring additional shares of the Company’s stock.

The New Rights will not be exercisable until the earlier to occur of (i) the close of business on the tenth business day after a public announcement or filing that a person has, or group of affiliated or associated persons have, become an “Acquiring Person,” which is defined as a person or group of affiliated or associated persons who, at any time after the date of the NOL Rights Agreement, have acquired, or obtained the right to acquire, beneficial ownership of 4.9% or more of the Company’s outstanding shares of Common Stock, subject to certain exceptions or (ii) the close of business on the tenth business day after the commencement of, or announcement of an intention to commence, a tender offer or exchange offer the consummation of which would result in any person becoming an Acquiring Person (the earlier of such dates being called the “Distribution Date”). Certain synthetic interests in securities created by derivative positions, whether or not such interests are considered to be ownership of the underlying Common Stock or are reportable for purposes of Regulation 13D of the Exchange Act, are treated as beneficial ownership of the number of shares of Common Stock equivalent to the economic exposure created by the derivative position, to the extent actual shares of the Common Stock are directly or indirectly held by counterparties to the derivatives contracts.

With respect to certificates representing shares of Common Stock outstanding as of the Record Date, until the Distribution Date, the New Rights will be evidenced by such certificates for shares of Common Stock registered in the names of the holders thereof, and not by separate Rights Certificates, as described further below. With respect to book entry shares of Common Stock outstanding as of the Record Date, until the Distribution Date, the New Rights will be evidenced by the balances indicated in the book entry account system of the transfer agent for the Common Stock. Until the earlier of the Distribution Date and the Expiration Date, as described below, the transfer of any shares of Common Stock outstanding on the Record Date will also constitute the transfer of the New Rights associated with such shares of Common Stock. As soon as practicable after the Distribution Date, separate certificates evidencing the New Rights (“Right Certificates”) will be mailed to holders of record of the Common Stock as of the close of business on the Distribution Date, and such Right Certificates alone will evidence the New Rights.

The New Rights, which are not exercisable until the Distribution Date, will expire prior to the earliest of (i) May 6, 2022 or such later day as may be established by the Board prior to the expiration of the New Rights, provided that the extension is submitted to the Company’s stockholders for ratification at the next annual meeting of stockholders of the Company succeeding such extension; (ii) the time at which the New Rights are redeemed pursuant to the NOL Rights Agreement; (iii) the time at which the New Rights are exchanged pursuant to the NOL Rights Agreement; (iv) the time at which the New Rights are terminated upon the occurrence of certain transactions; (v) the close of business on the effective date of the repeal of Section 382 of the Tax Code, if the Board determines that the NOL Rights Agreement is no longer necessary or desirable for the preservation of Tax Benefits; and (vi) the close of business on the first day of a taxable year of the Company to which the Board determines that no Tax Benefits are available to be carried forward, (the earliest of (i), (ii), (iii), (iv), (v), (vi) and (vi) is referred to as the “Expiration Date”).

Each share of Preferred Stock will be entitled, when, as and if declared, to a preferential per share quarterly dividend payment equal to the greater of (i) $1.00 per share or (ii) an amount equal to 1,000 times the aggregate quarterly dividend declared per share of Common Stock since the immediately preceding quarterly dividend payment date for the Common Stock (or, with respect to the first quarterly dividend payment on the Common Stock, since the first issuance of the Preferred Stock). Each share of Preferred Stock will entitle the holder thereof to 1,000 votes on all matters submitted to a vote of the stockholders of the Company. In the event of any merger, consolidation or other transaction in which shares of Common Stock are converted or exchanged, each share of Preferred Stock will be entitled to receive 1,000 times the amount received per one share of Common Stock.