X0306 4 2022-02-08 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 2022-02-08 4 A 0 268358 0.00 A 5641617 D Common Stock 2022-02-08 4 A 0 207367 0.00 A 2466067 I See footnote The shares are represented by restricted stock units, or RSUs, which vest in 16 equal quarterly installments beginning on May 20, 2022. Reflects an increase of 176 shares pursuant to an adjustment of earnout shares reported on a Form 4 filed on November 12, 2021. Reflects an increase of 73 shares pursuant to an adjustment of earnout shares reported on a Form 4 filed on November 12, 2021. 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 2022-02-09 /s/ Amir Moftakhar, by power of attorney for Julia Song 2022-02-09