Energy storage company ESS Tech Inc. today is commissioning the first part of what will be a 200-megawatt installation in the territory of the Sacramento Municipal Utility District of iron-flow battery technology to save renewable power for times of no wind or sunlight.
The installation, which will be the largest of its kind to date in the U.S., is part of SMUD’s strategy to get to 100% renewable electricity and go to zero-carbon by 2030, which is 15 years ahead of the statewide goal.
"SMUD is on a bold journey to eliminate all carbon emissions from our power supply by 2030 without compromising our world-class reliability and rates that are consistently among the lowest in California,” said SMUD CEO Paul Lau, in a news release. “In addition to accelerating our transition to a clean energy future, this partnership and technology will spur economic development, equitable access to clean energy and a brighter future for the entire Sacramento region."
Wilsonville, Oregon-based ESS (NYSE: GWH) also plans to develop with SMUD a Center of Excellence to train workers to build, install and maintain the batteries in Sacramento and potentially for the California market.
Each ESS iron-flow battery is housed in a 40-foot-long shipping container, about the size of a rail car. Each one can store 75 kilowatts of electricity. To get to 200 megawatts, it will take more than 265 of them.
These first six container batteries will be able to deliver about 450 kilowatts of electricity. ESS will deliver the total 200 megawatts of batteries over seven years, according to the contract. The price of the installation isn’t being released, said spokeswoman Carly Cao. A megawatt is enough to power more than 750 homes.
Iron-flow batteries are often used for backup power. They can cycle tens of thousands of times from charging to releasing energy without losing capacity over a 25-year lifespan. Iron-flow batteries are also stable and don’t require the use of rare chemicals. Their primary ingredients are iron and saltwater. These will be the first iron-flow batteries used by SMUD.
By comparison, SMUD in the last year installed lithium-ion battery storage units at its Hedge Solar Farm on Tokay Lane that are housed in 20-foot shipping containers that each can store 667 kilowatts. Lithium-ion batteries last for only about 4,000 cycles and, when used up, leave hazardous waste.
