Entergy plans two big batteries in Mississippi and Hot Spring counties

LITTLE ROCK — Entergy Arkansas wants to build two large battery plants, one in northeast Arkansas and one near Hot Springs, to store electricity and send it back to the grid when demand is highest.

The utility filed its plans Thursday with the Arkansas Public Service Commission, which must approve them. Entergy says the batteries are needed to help power the expansion of Google’s data center in West Memphis, and that Google will cover their cost.

Where they would go

Driver battery, Mississippi County. The larger battery would be built inside the fence of Entergy’s Driver Solar plant near Osceola, on land not used by the solar panels. It would connect to the solar plant’s existing substation. Entergy says that lets it use grid connections it already has.

Jones Mill battery, Hot Spring County. The smaller battery would go on a former industrial site next to the Arklahoma substation near Jones Mill, close to Entergy’s Lake Catherine power plant. That area is now used for storing construction gravel and for a truck-driving school, according to the filing. It would connect to the substation by a short line of about 200 to 300 feet. Entergy plans to retire Lake Catherine’s Unit 4 at the end of 2027, and the battery would take over part of that unit’s grid connection.

How big

• Driver: 250 megawatts. It could run at full power for four hours. Estimated cost: $389.4 million.
• Jones Mill: 100 megawatts, also four hours. Estimated cost: $161.2 million.

Together, the two would cost about $550.6 million. Arkansas now has only a few small grid batteries; the largest is a 10-megawatt battery at Entergy’s Searcy Solar plant. The Driver battery alone holds enough energy to cover a full day’s electricity use for roughly 29,000 average Arkansas homes.

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Why Entergy wants them

A grid battery doesn’t make electricity. It charges when power is plentiful and cheap, such as midday when solar plants are producing the most or late at night, and it releases that power during peak hours like hot summer evenings.

Entergy gave three main reasons:

• Google’s expansion. The batteries are “a key component of the supply solution needed to serve Google’s project expansion,” Kristin Dalrymple, Entergy Arkansas’ vice president of business operations and strategy, said in testimony.
• Peak power for everyone. Entergy says the batteries will serve all its customers, not just Google, by adding 350 megawatts it can call on at peak times.
• Lower costs. The batteries would reduce the power Entergy has to buy on the regional market when prices spike. Entergy estimates customers would see about $561 million in net benefits over about 20 years compared with other options.

The batteries were picked through a request for proposals Entergy issued in 2025.

Who pays

Under Entergy’s contract with Google, Google will pay the financing costs while the batteries are built. It will also pay rates covering their full cost for the length of the 20-year contract, Entergy said.

Entergy says other customers won’t see an increase. It estimates a typical household’s bill would fall about 4 cents a month in 2029, because the batteries would lower fuel costs.

Unlike the Google-linked Cypress Solar plant in Jefferson County, Entergy isn’t asking to charge customers for the batteries while they are under construction.

Jobs and taxes

Entergy expects about 50 temporary construction jobs at Driver and 25 at Jones Mill. It estimates the Driver project would generate $1.9 million in property tax and $13.5 million in sales tax. Jones Mill would generate about $6 million in sales tax and a similar amount in property tax.

When

Construction would start in spring 2027, with both batteries running by June 1, 2028, if regulators approve. State law gives the commission 180 days to decide, putting a ruling due by late April.

The plans are part of a larger package Entergy and Google announced Oct. 19. It also includes a solar power purchase from the Big Island Solar project in Mississippi County, an expanded substation near West Memphis and two new transmission lines.

The application is public in Docket 26-073-U on the commission’s website.