---
schema_version: "secwatch.filing_event.v1"
accession: "0001628280-23-016813"
form_type: "8-K"
ticker: "GWH"
cik: "0001819438"
company_name: "ESS Tech, Inc."
filed_at: "2023-05-09T23:59:59+00:00"
generated_at: "2026-06-15T09:47:23.017643+00:00"
event_type: "earnings"
sentiment: "neutral"
materiality_score: 0.5
calibrated_materiality_score: 0.5
confidence: "low"
source: SEC EDGAR
---

# ESS Tech Q1 2023 revenue impacted by project delays; partnership with Coldwell Solar

## Summary
- Built nine Energy Warehouses in Q1, continuing production pace from Q4.
- Project delays at a customer site limited shipments and revenue recognition in Q1.
- Partnership with Coldwell Solar to install three Energy Warehouses for a microgrid in California, expected operational late 2023.
- ESS LDES units received UL 1973 certification for stationary energy storage systems.
- Total patents reached 62 worldwide as of March 31, 2023, with 225 applications filed.

## SEC filing metadata
- accession: 0001628280-23-016813
- form_type: 8-K
- ticker: GWH
- cik: 0001819438
- company_name: ESS Tech, Inc.
- filed_at: 2023-05-09T23:59:59+00:00
- event_type: earnings
- sentiment: neutral
- materiality_score: 0.5
- calibrated_materiality_score: 0.5
- confidence: low
- sec_items: 2.02, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1819438/000162828023016813/0001628280-23-016813-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1819438/000162828023016813/wk-20230509.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001628280-23-016813
- JSON: https://secwatch.observer/filing/0001628280-23-016813.json
- Plain text: https://secwatch.observer/filing/0001628280-23-016813.txt

## Key facts
- Earnings Releases
  ESS Tech, Inc. reported financial results for first quarter of 2023 ended March 31, 2023.
  - Period: first quarter of 2023 ended March 31, 2023
  - Result: reported results
  source text: On May 9, 2023 , ESS Tech, Inc. (the “Company”) issued a press release announcing financial results for the quarter ended March 31, 2023.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1819438/000162828023016813/0001628280-23-016813-index.htm

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