X0306 4 2022-01-24 0 0001819438 ESS Tech, Inc. GWH 0001885331 Evans Craig E C/O ESS TECH, INC. 26440 SW PARKWAY AVE., BLDG. 83 WILSONVILLE OR 97070 1 1 0 0 President 0001884681 Song Julia C/O ESS TECH, INC. 26440 SW PARKWAY AVE., BLDG. 83 WILSONVILLE OR 97070 0 1 0 0 Chief Technology Officer Common Stock 2022-01-24 4 S 0 1342 6.0528 D 5373083 D Common Stock 2258627 I See footnote 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. The shares are held directly by Julia Song. The reporting persons are husband and wife. /s/ Amir Moftakhar, by power of attorney for Craig E. Evans 2022-01-25 /s/ Amir Moftakhar, by power of attorney for Craig E. Evans 2022-01-25