ESS Tech, Inc.

To achieve our goals, we have designed, and intend to modify as necessary, our compensation and benefits program to attract, retain, incentivize and reward deeply talented and qualified executives who share our philosophy and desire to work towards achieving these goals.

We believe our compensation program should promote our success and align executive incentives with the long-term interests of our shareholders. Our current compensation programs consist primarily of salary, cash bonuses and stock awards. As our needs evolve, we intend to continue to evaluate our philosophy and compensation programs as circumstances require.

This section provides an overview of our executive compensation programs, including a narrative description of the material factors necessary to understand the information disclosed in the summary compensation table below.

Compensation Committee Interlocks and Insider Participation

During the year ended December 31,2024, the members of our compensation committee were Mr. Garabedian, Mr. Quarls and Mr. Teamey. None of the members of our compensation committee is or has been an officer or employee of our company. None of our executive officers currently serves, or in the past fiscal year has served, as a member of the board of directors or compensation committee (or other board committee performing equivalent functions) of any entity that has one or more executive officers serving on our board of directors or compensation committee.

Named Executive Officers

Our board of directors and the compensation committee, with input from our Chief Executive Officer (for executive officers other than the Chief Executive Officer), determines the compensation for our named executive officers. For the year ended December 31, 2024, our named executive officers were:

•Eric Dresselhuys, our former Chief Executive Officer and Director; and

•Anthony Rabb, our Chief Financial Officer.

Summary Compensation Table

The following table sets forth information regarding the compensation reportable for our named executive officers for fiscal year 2024 and prior years where applicable, as determined under SEC rules.

(1)The amounts in this column represent the aggregate grant-date fair value of awards granted to each named executive officer, computed in accordance with the Financial Accounting Standards Board’s, or the FASB’s, Accounting Standards Codification, or ASC, Topic 718. See Note 12, Stock-based Compensation, to our financial statements included elsewhere in this Annual Report on Form 10-K, for a discussion of the assumptions made by us in determining the grant-date fair value of our equity awards. With respect to Mr. Dresselhuys, unvested and outstanding time-based equity awards scheduled to vest within six months of his resignation were accelerated and any remaining unvested and outstanding time-based equity awards were forfeited.

(2)The amounts in this column include matching 401(k) contributions.

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Narrative Disclosure to Summary Compensation Table

For 2024, the compensation program for our named executive officers consisted of base salary, incentive compensation delivered in the form of a bonus, restricted stock unit awards and 401(k) matching contributions.

Base Salary

Base salary is set at a level that is commensurate with the named executive officer’s duties and authorities, contributions, prior experience and sustained performance. For 2024, our named executive officers had the following annual base salaries: $500,000 in the case of Mr. Dresselhuys and $427,450 in the case of Mr. Rabb.

Cash Bonus

Each of our named executive officers is eligible for an annual bonus under our Employee Incentive Compensation Plan. For fiscal year 2024, our board of directors determined not to award a bonus to Mr. Dresselhuys and to award a bonus of $176,323 to Mr. Rabb, based upon an assessment of achievement of corporate goals, which included specified technology, engineering, product development, operations and manufacturing, business development and sales, and finance goals.

Stock Awards and Stock Option Awards

In 2024, restricted stock unit awards were granted to our named executive officers under the 2021 Plan.

Policies and Practices Related to the Grant of Certain Equity Awards

We generally do not grant awards of stock options, stock appreciation rights, or similar option-like instruments. Accordingly, we currently have no specific policy or practice on the timing of awards of such options in relation to the disclosure of material nonpublic information by our Company. In the event that we determine to grant new awards of such options in the future, our board of directors will evaluate the appropriate steps to take in relation to the foregoing.

Employment Arrangements

Eric Dresselhuys

Mr. Dresselhuys served as our Chief Executive Officer from March 2021 until February 13, 2025 and a member of our board of directors from May 2021 until February 13, 2025. From March 2017 to March 2021, Mr. Dresselhuys served as Chief Executive Officer of Juncion, Inc., a private energy company he founded. Also, from January 2018 to July 2020, Mr. Dresselhuys served as President - Development of Smart Energy Water, a software‑as‑a‑platform for the energy, water and utility sector. From July 2002 to March 2017, he served in various management roles at Silver Spring Networks, Inc., a smart grid products company he co-founded which is now a subsidiary of Itron Inc. (Nasdaq: ITRI), most recently as Executive Vice President, Global Development. Mr. Dresselhuys has served on the boards of directors of various private companies, including Enian, LTD a provider of project management software for renewable energy professionals and AutoGrid Solutions, a provider of distributed resource management analytics and software. Mr. Dresselhuys holds a B.S. in Economics from the University of Wisconsin and earned an Executive Certificate from the Sloan School at the Massachusetts Institute of Technology.

We entered into an employment agreement with Mr. Dresselhuys, our former Chief Executive Officer, on April 1, 2021. Mr. Dresselhuys’s employment agreement provided for an initial term from March 25, 2021 through March 25, 2025, with additional one-year terms thereafter, unless either the Company or Mr. Dresselhuys provided notice of the decision to not renew the term at least 60 days before the end of a term.

The employment agreement provided that if we terminated Mr. Dresselhuys’s employment without cause or Mr. Dresselhuys terminated his employment for “good reason” (as defined in Mr. Dresselhuys’s employment agreement) other than in connection with a “change in control” (as defined in Mr. Dresselhuys’s employment agreement), then Mr. Dresselhuys would be entitled to continuing payments of base salary and Company-paid COBRA coverage for 12 months following such termination, a pro-rated bonus payment for the fiscal year in which such termination occurs based on actual achievement, any earned but unpaid bonus from the year prior to such termination, and acceleration of his unvested and outstanding time-based equity awards to the extent that such awards would have vested had his employment continued for an additional six months following such termination (except that, if the termination occurs between six months and 12 months after Mr. Dresselhuys’s start date, the number of months of additional vesting will be equal to the number of months of Mr. Dresselhuys’s service). The employment agreement also provided that if we terminated Mr. Dresselhuys’s

• 91 - employment without cause or Mr. Dresselhuys terminated his employment for good reason in connection with a change in control, then Mr. Dresselhuys would be entitled to continuing payments of base salary and Company-paid COBRA coverage for eighteen months following such termination, a pro-rated bonus payment for the fiscal year in which such termination occurs based on actual achievement, any earned but unpaid bonus from the year prior to such termination, and 100% acceleration of his unvested and outstanding equity awards, with performance-based awards accelerating at target achievement.

On February 13, 2025, Mr. Dresselhuys separated from the Company and resigned as a member of our board of directors. In connection with the separation, we entered into a Separation and Release Agreement with Mr. Dresselhuys dated as of February 13, 2025, pursuant to which Mr. Dresselhuys will be entitled to continuing payments of his base salary of $500,000, less applicable withholdings, and Company-paid COBRA coverage for twelve months, and acceleration of unvested and outstanding time-based equity awards vesting within the next six months. Such payments, which are consistent with the provisions of the employment agreement, are in consideration for, and contingent upon, among other things, Mr. Dresselhuys’s agreement to a standard release of claims. He remained a non-executive officer employee until February 14, 2025.

Anthony Rabb

We entered into an employment letter with Anthony Rabb, our Chief Financial Officer, on October 31, 2022. Mr. Rabb is an at-will employee. The Company or Mr. Rabb may terminate his employment at any time for any reason.

If we terminate Mr. Rabb’s employment without “cause” and other than for disability or death or Mr. Rabb terminates his employment for “good reason” (as those terms are defined in Mr. Rabb’s employment letter), then Mr. Rabb will be entitled to continuing payments of base salary and Company-paid COBRA coverage for 9 months following such termination, 75% of his cash bonus target for the fiscal year in which such termination occurs, and acceleration of his unvested and outstanding equity awards to the extent that such awards would have vested had his employment continued for an additional 12 months following such termination.

Outstanding Equity Awards at Fiscal 2024 Year-End

The following table sets forth information regarding outstanding equity awards held by our named executive officers as of December 31, 2024. Market value of shares that have not vested is based on our closing trading price of $5.88 per share on December 31, 2024.

(1)Awards granted on or prior to October 8, 2021 were granted pursuant to the 2014 Equity Incentive Plan, or 2014 Plan, and those granted after October 8, 2021 were granted pursuant to the 2021 Equity Incentive Plan, or 2021 Plan. With respect to Mr. Dresselhuys, unvested and outstanding time-based equity awards scheduled to vest within six months of his resignation were accelerated and any remaining unvested and outstanding time-based equity awards were forfeited.

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(2)1/4th of the total shares vested on March 25, 2022, and 1/48th will vest each month thereafter, subject to the holder’s continuous service through each vesting date.

(3)Vesting is subject to performance milestones, subject to the holder’s continuous service through each vesting date.

(4)Beginning on May 20, 2022,1/16th of the total shares vest each quarter, subject to the holder’s continuous service through each vesting date.

(5)Beginning on May 20, 2023,1/16th of the total shares vest each quarter, subject to the holder’s continuous service through each vesting date.

(6)1/3 of the total shares vested on May 9, 2024 and 1/3 of the shares will vest annually thereafter, subject to the holder’s continuous service through each vesting date.

(7)1/3 of the total shares vested on November 20, 2024 and 1/3 will vest annually thereafter, subject to the holder’s continuous service through each vesting date.

(8)Beginning on May 20, 2024,1/16th of the total shares vest each quarter, subject to the holder’s continuous service through each vesting date.

(9)1/4th of the total shares vested on November 2, 2023, and 1/16th will vest quarterly thereafter, subject to the holder’s continuous service through each vesting date.

Role of Compensation Consultant

The compensation committee expects to engage outside consultants every two to three years. Since 2021, the compensation committee has directly retained the services of Pearl Meyer and Partners, LLC, or Pearl Meyer, an independent national executive compensation consulting firm, to assist it in fulfilling its duties and responsibilities. Pearl Meyer does not provide services to the company or its management outside of the services provided to the compensation committee unless directed by the compensation committee.

The consultants were asked to review and analyze comparisons of senior executive compensation and benefits and director compensation utilizing independent surveys and their own database of compensation information. The consultants provided conclusions regarding the salary and benefit levels of senior management and the board of directors. The compensation committee has assessed the independence of Pearl Meyer, as required under NYSE rules. The compensation committee has also considered and assessed all relevant factors, including but not limited to those set forth in Rule 10C-1(b)(4)(i) through (vi) under the Exchange Act, that could give rise to a potential conflict of interest with respect to the compensation consultant described above. Based on this review, we are not aware of any conflict of interest that has been raised by the work performed by Pearl Meyer.

Director Compensation

To attract, retain and reward qualified non-employee candidates to serve on our board of directors, we have adopted an outside director compensation policy (as amended, the “Director Compensation Policy”). The compensation committee reviews the Director Compensation Policy annually in consultation with the company’s compensation consultant, and makes recommendations for any revisions to the board of directors. In January 2025, our board of directors revised the Director Compensation Policy to provide that the annual award of restricted stock units will be for a fixed number of shares. See “—Equity Compensation” below for further details. No other adjustments were made to director compensation.

Under the Director Compensation Policy, as currently in effect, each non-employee director is eligible to receive compensation for his or her service consisting of the following cash and equity components. Our board of directors has the discretion to revise non-employee director compensation as it deems necessary or appropriate.

Annual Cash Retainer

Each non-employee director will be paid an annual cash retainer of $50,000. There are no per-meeting attendance fees for attending meetings of the board of directors. This cash compensation will be paid quarterly in arrears on a prorated basis.

Committee Annual Cash Retainer

Each non-employee director who serves as the chair of the board of directors, lead independent director, or the chair or a member of a committee of the board of directors listed below will be eligible to earn additional annual cash fees (paid quarterly in arrears on a prorated basis) as follows:

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Equity Compensation

Under our Director Compensation Policy, each individual who first becomes a non-employee director automatically will be granted an award of restricted stock units covering a number of our shares having a value equal to $200,000, rounded down to the nearest whole share. Each award will vest in equal 1/3 installments on each anniversary following the grant date, subject to the non-employee director continuing to be a service provider through the applicable vesting date.

Additionally, effective as of January 2025, on the date of each of our annual meetings, each non-employee director automatically will be granted an award of restricted stock units for 13,513 shares. Each award will vest on the earlier of (i) the one-year anniversary of the date the award is granted or (ii) the day prior to the date of the annual meeting next following the date the award is granted, in each case, subject to the director continuing to be a service provider through the applicable vesting date.

In addition, the non-executive chair of our board of directors will also be granted (i) a one-time award of options covering a number of our shares having a value equal to $300,000, rounded down to the nearest whole share (the “Supplemental Initial Award”) and (ii) an annual award of restricted stock units covering a number of our shares having a value of $300,000, rounded down to the nearest whole share. The Supplemental Initial Award will be a nonstatutory stock option for U.S. tax purposes, will have a term of ten years, subject to earlier termination, and will vest in equal 1/3 installments on each anniversary following the grant date, subject to the non-executive chair’s continuing to be a service provider through the applicable vesting date. The annual award of restricted stock units replaces and is not in addition to the award of restricted stock units which the non-executive chair would otherwise be eligible to receive as a member of our board of directors.

Director Compensation for Fiscal 2024

The table below summarizes the compensation of each person serving as an ESS non-employee director for the year ended December 31, 2024. Mr. Dresselhuys did not receive any additional compensation for his service as director in 2024. The compensation of Mr. Dresselhuys as a named executive officers is set forth above under “—Summary Compensation Table.”

The following table presents information regarding outstanding equity awards held by our non-employee directors as of December 31, 2024.

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