RWE has completed three large BESS projects totalling 190MW in the US states of Texas and Arizona.
The company's global battery energy storage capacity now stands at 700MW, with more than 1GW of projects under construction.
The new BESS projects are integrated with solar power facilities to mitigate the intermittent nature of solar and wind power. They provide flexible electricity supply, particularly during peak demand periods, by storing surplus electricity from solar arrays and dispatching it to the grid when required.
The Bright Arrow project in Sulphur Springs, Texas, features a 100MW, 200 megawatt-hour (MWh) BESS paired with 300MW of solar photovoltaic (PV) power.
It has been operational since December 2023. A further 200MW of solar power will be delivered in spring 2024.
The BESS will engage in the Energy Reliability Council of Texas (ERCOT) market, with solar PV output supplied to an NRG Energy affiliate.
The Big Star project in Bastrop County, Texas, comprises 80MW (120MWh) of battery storage and 200MW of solar PV.
Currently in its testing phase, it is set to begin commercial operations in March 2024. This BESS will also participate in the ERCOT market, with the solar PV output contracted to a third party.
In Maricopa County, Arizona, the Mesquite 4 project includes a 10MW (40MWh) battery storage system and a 52.5MW solar facility.
Set to become operational in February 2024, it will increase the Mesquite complex's total capacity to 530MW. The solar PV and BESS services will be provided to the Modesto Irrigation District.
RWE clean energy CEO Andrew Flanagan stated: “Battery storage is growing even more critical to enable the rapid deployment of wind and solar projects, stabilise the US power grid and better ensure that enough electric supply is available to meet demand.
“As part of our Growing Green Strategy, we are planning to increase our battery portfolio globally to 6GW by 2030, and these three new systems are contributing to that goal.”
In December 2023, Vattenfall agreed to sell its Norfolk, UK, offshore wind zone to RWE for an enterprise value of £963m ($1.2bn).
The transaction enables the continued development of three wind farms with a combined capacity of 4.2GW, sufficient to power four million British homes.