Harlingen's biggest battery storage plant nearing operation

HARLINGEN - Rising out of swaths of farmland, rows of long tanks storing lithium-ion batteries stand across a six-acre site south of Valley International Airport.

For months, some residents here raised concerns developers were building a data center off Grimes Street and Loop 499.

Instead, the city's biggest battery storage plant's nearing completion.

For more than three years, developers have been planning the project.

In 2023, city commissioners granted Black Mountain Energy Storage, a Fort Worth company, a special use permit to develop the project, aiming to shore up the electric grid.

After purchasing the development later that year, East Point Energy, a Charlottesville, Virginia-based company, is now completing the project, a 100-megawatt plant capable of powering thousands of homes for two-hour durations.

Now, the company is working with the Electric Reliability Council of Texas, or ERCOT, to test the plant, expected to go into operation as early as this month.

"We're working on testing with ERCOT and AEP to ensure that when we come online we can do so safely and in compliance with their regulations," Maggie Howe, East Point Energy's vice president for project development, told city commissioners during a May 20 meeting.

At City Hall, some residents have expressed concern developers were building a sprawling data center like an Eneus Energy project that's been making news headlines.

"I know you all were kind of on the receiving end of some information out there, assuming that it was a data center and not understanding the difference in what your role plays in actually supporting the community and ensuring that there's a potential of supporting thousands and thousands of homes in our community, which is fantastic," Mayor Norma Sepulveda told Howe during the meeting.

During a her presentation, Howe said the plant will have the capacity to power as many as 80,000 homes for two-hour durations before charging up again, while generating about $19 million in property tax revenue during its lifespan of 20 to 30 years.

"It's going to satisfy the needs of Harlingen first and then it's going to sort of move out in widening circles from there until it is consumed," she said, referring to the plant's electrical generation, adding, "We can't export beyond ERCOT's boundaries, so it will stay local in Texas."

In 2023, developers picked the project site, planning to connect the plant onto the area's AEP substation.

"It connects into the transmission grid and helps to stabilize the grid and create a grid that's more clean, resilient and affordable," Howe said. "Batteries are a key asset to help stabilize that grid and ensure that there is consistent flow of electricity, of high-quality electricity, of affordable electricity at all times when it's needed."

The plant's batteries will store electricity before releasing power during periods of high demand, helping to stabilize prices, she said.

"The batteries will store electricity when there is a surplus of some kind on the grid or when the cost of electricity is quite low and then it puts out electricity back on the grid as demand rises and offers competition for the most expensive sources of electrical generation, which helps stabilize prices," Howe said.

After working with EROCT to complete its testing phase, the plant's expected to go into operation this summer, as early as this month, she said.

While plans call for landscaping along the front of the plant, the company's planning to work with local artists to paint a mural across its walls facing Loop 499, she said.

So far, East Point Energy's plant, generating 100-megawatts of power, is the biggest that developers are planning to open here.

In the last four years, commissioners have granted special use permits to about five developers planning to build battery storage plants.

In late 2023, the city's first plant, generating 10 megawatts of power, went into operation off West Lincoln Avenue near Tucker Road.

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