# EDGAR Filing Document

**Accession Number:** 0001819438
**File Stem:** 0001628280-23-006779
**Filing Date:** 2023-3
**Character Count:** 8843
**Document Hash:** 90c877d1880dab5e9f5514fad02c396c
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001628280-23-006779.hdr.sgml**: 20230307

**ACCESSION NUMBER**: 0001628280-23-006779

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 2

**CONFORMED PERIOD OF REPORT**: 20230306

**FILED AS OF DATE**: 20230307

**DATE AS OF CHANGE**: 20230307

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** NIGGLI MICHAEL R
- **CENTRAL INDEX KEY:** 0001377160

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-39525
- **FILM NUMBER:** 23713811

**MAIL ADDRESS:**
- **STREET 1:** 101 ASH STREET HQ18
- **CITY:** SAN DIEGO
- **STATE:** CA
- **ZIP:** 92101
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** ESS Tech, Inc.
- **CENTRAL INDEX KEY:** 0001819438
- **STANDARD INDUSTRIAL CLASSIFICATION:** MISCELLANEOUS ELECTRICAL MACHINERY, EQUIPMENT & SUPPLIES [3690]
- **IRS NUMBER:** 000000000
- **STATE OF INCORPORATION:** E9
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 26440 SW PARKWAY AVE.
- **STREET 2:** BLDG. 83
- **CITY:** WILSONVILLE
- **STATE:** OR
- **ZIP:** 97070
- **BUSINESS PHONE:** (855) 423-9920

**MAIL ADDRESS:**
- **STREET 1:** 26440 SW PARKWAY AVE.
- **STREET 2:** BLDG. 83
- **CITY:** WILSONVILLE
- **STATE:** OR
- **ZIP:** 97070

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** ACON S2 Acquisition Corp.
- **DATE OF NAME CHANGE:** 20200728

## Ex-24

```
<pre>
POWER OF ATTORNEY

       The undersigned, as a Section 16 reporting person of ESS Tech, Inc. (the "Company"),
hereby constitutes and appoints Eric P. Dresselhuys, Anthony Rabb and Kelly F. Goodman, and
each of them, as the undersigned's true and lawful attorney-in-fact to:

1.    complete and execute Forms 3, 4 and 5 and other forms and all amendments
thereto as such attorney-in-fact shall in his or her discretion determine to be
required or advisable pursuant to Section 16 of the Securities Exchange Act of
1934 (as amended) and the rules and regulations promulgated thereunder, or any
successor laws and regulations, as a consequence of the undersigned's
ownership, acquisition or disposition of securities of the Company; and

2.    do all acts necessary in order to file such forms with the SEC, any securities
exchange or national association, the Company and such other person or agency
as such attorney-in-fact shall deem appropriate.

       The undersigned hereby ratifies and confirms all that said attorneys-in-fact and agents
shall do or cause to be done by virtue hereof.  The undersigned acknowledges that the foregoing
attorneys-in-fact, in serving in such capacity at the request of the undersigned, are not assuming,
nor is the Company assuming, any of the undersigned's responsibilities to comply with
Section 16 of the Securities Exchange Act of 1934 (as amended).

       This Power of Attorney shall remain in full force and effect until the undersigned is no
longer required to file Forms 3, 4 and 5 with respect to the undersigned's holdings of and
transactions in securities issued by the Company, unless earlier revoked by the undersigned in a
signed writing delivered to the Company and the foregoing attorneys-in-fact.

       IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be
executed as of this 2nd day of December, 2022.

Signature:  /s/Michael Niggli

Print Name: Michael Niggli

</pre>
```

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## FORM 4

### STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

[ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

[ ] Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>NIGGLI MICHAEL R<br><sub>(Last) (First) (Middle)</sub><br>C/O ESS TECH, INC.<br>26440 SW PARKWAY AVE., BLDG. 83<br><sub>(Street)</sub><br>WILSONVILLE, OR 97070<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2023-03-06 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [ ] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>ESS Tech, Inc. [ GWH ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[X] Form filed by One Reporting Person<br>[ ] Form filed by More than One Reporting Person |

---

## Table I - Non-Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | 3. Transaction Code (V) | 3. Transaction Code (V) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | Code | V | Amount | (A) or (D) | Price | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| Common Stock | 2023-03-06 |  | P |  | 5000 | A | $1.65 | 583821 | D |  |
| Common Stock |  |  |  |  |  |  |  | 568312 | I | See footnote<sup>(1)</sup> |
| Common Stock |  |  |  |  |  |  |  | 227407 | I | See footnote<sup>(2)</sup> |
| Common Stock |  |  |  |  |  |  |  | 85228 | I | See footnote<sup>(3)</sup> |
| Common Stock |  |  |  |  |  |  |  | 85228 | I | See footnote<sup>(4)</sup> |
| Common Stock |  |  |  |  |  |  |  | 85228 | I | See footnote<sup>(5)</sup> |
| Common Stock |  |  |  |  |  |  |  | 85228 | I | See footnote<sup>(6)</sup> |

---

## Table II - Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | 4. Transaction Code (V) | 4. Transaction Code (V) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 6. Date Exercisable and Expiration Date | 6. Date Exercisable and Expiration Date | 7. Title and Amount of Underlying Securities | 7. Title and Amount of Underlying Securities | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | Code | V | (A) | (D) | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

---

### Footnotes:

(1) The shares are held of record by the Linda Naviaux Niggli Trust for which the reporting person's spouse serves as trustee.

(2) The shares are held of record by the Michael R. Niggli Family Trust for which the reporting person serves as trustee.

(3) The shares are held of record by the Michael R. Niggli Jr. 2021 Gift Trust for which the reporting person serves as trustee.

(4) The shares are held of record by the Chloe D. Niggli Gift Trust for which the reporting person serves as trustee.

(5) The shares are held of record by the Ian M. Niggli 2021 Gift Trust for which the reporting person serves as trustee.

(6) The shares are held of record by the Lorelei A. Niggli 2021 Gift Trust for which the reporting person serves as trustee.

**Signature:** /s/Kelly F. Goodman, by power of attorney for Michael R. Niggli  
**Date:** 2023-03-08

### Remarks:

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

**Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.**