---
schema_version: "secwatch.filing_event.v1"
accession: "0001628280-23-030822"
form_type: "8-K"
ticker: "GWH"
cik: "0001819438"
company_name: "ESS Tech, Inc."
filed_at: "2023-08-29T23:59:59+00:00"
generated_at: "2026-06-11T02:28:35.755445+00:00"
event_type: "leadership"
sentiment: "neutral"
materiality_score: 0.5
calibrated_materiality_score: 0.5
confidence: "high"
source: SEC EDGAR
---

# ESS Tech appoints Harry Quarls as Chairman; Niggli stays as Founding Chairman

## Summary
- Board expanded from 7 to 8 directors; Quarls appointed as Chairman and Class II director.
- Michael Niggli steps down as Chairman but remains on board as Founding Chairman and on audit committee.
- Quarls receives initial RSU grant of $200K, vests 1/3 annually; supplemental option grant for 1.5x shares.
- Quarls eligible for annual RSU award of $300K after first annual meeting; plus $75K cash retainer annually.
- Quarls brings 40 years of energy experience from Global Infrastructure Partners and Booz & Company.

## SEC filing metadata
- accession: 0001628280-23-030822
- form_type: 8-K
- ticker: GWH
- cik: 0001819438
- company_name: ESS Tech, Inc.
- filed_at: 2023-08-29T23:59:59+00:00
- event_type: leadership
- sentiment: neutral
- materiality_score: 0.5
- calibrated_materiality_score: 0.5
- confidence: high
- sec_items: 5.02, 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1819438/000162828023030822/0001628280-23-030822-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1819438/000162828023030822/wk-20230828.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001628280-23-030822
- JSON: https://secwatch.observer/filing/0001628280-23-030822.json
- Plain text: https://secwatch.observer/filing/0001628280-23-030822.txt

## Key facts
- Executive change
  Harry Quarls was appointed as Chairman of the Board at ESS Tech, Inc..
  - Action: appointed
  - Role: Chairman of the Board
  source text: the Board appointed Harry Quarls as a member of the Board and as Chairman of the Board.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1819438/000162828023030822/0001628280-23-030822-index.htm
- Executive change
  Michael R. Niggli resigned as Founding Chairman at ESS Tech, Inc..
  - Action: resigned
  - Role: Founding Chairman
  source text: Michael R. Niggli resigned as Chairman of the Board and the Board appointed Harry Quarls as a member of the Board and as Chairman of the Board.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1819438/000162828023030822/0001628280-23-030822-index.htm

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.