X0306 4 2022-01-24 0 0001819438 ESS Tech, Inc. GWH 0001571531 Dresselhuys Eric P. C/O ESS TECH, INC. 26440 SW PARKWAY AVE., BLDG. 83 WILSONVILLE OR 97070 1 1 0 0 Chief Executive Officer Common Stock 2022-01-24 4 S 0 59642 6.0528 D 869170 D The reported shares were sold to satisfy the reporting person's tax obligations in connection with the vesting of restricted stock units, or RSUs. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $6.02 to $6.08, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price. /s/ Amir Moftakhar, by power of attorney 2022-01-25