Planned size of the Utah BESS project by PacifiCorp and rPlus has been quadrupled to 1,600MWh

Developer rPlus Energies and utility PacifiCorp have amended an existing PPA for a solar-plus-storage project in Utah, to increase the energy storage resource’s planned size from 400MWh to 1,600MWh.

The two companies have agreed to change the previously-agreed power purchase agreement (PPA) for the Green River Energy Center project in Emergy County, Utah, US, they announced today (6 March).

The project will start construction in Q2 2024 and will now feature a 1,600MWh battery energy storage system (BESS) alongside 400MW of solar PV. Previous announcements about the size of the solar and BESS indicate the new size is 400MW/1,600MWh, a 4-hour duration system.

At 1,600MWh it would be one of the largest BESS units in the US and, by extension, the world – the current largest is at the Edwards Sanborn solar-plus-storage facility in California which came online in January.

Green River Energy Center is the seventh largest solar-plus-storage project under development in the US according to trade body American Clean Power figures cited by rPlus. It is the third PPA between rPLus and PacifiCorp, with the utility aiming to have 7.4GW of energy storage in its network by 2029.

rPlus aims to bring the Utah solar-plus-storage project, which will require US$1 billion of capital investment, to the market for tax and debt financing later this year.

The company, through its subsidiary rPlus Hydro, is also active in developing pumped hydro energy storage (PHES) projects including in both Wyoming and Utah.

Utah has been relatively quiet compared to other states around it for downstream energy storage deployments, though it is the site of one of the largest green hydrogen projects in the world as well as the state where system integrator Fluence is launching US manufacturing of BESS.