Across US, batteries and green energies combine for major climate solution

In the Arizona desert, a Danish company is building a massive solar farm that includes batteries that charge when the sun is shining and supply energy back to the electric grid when it's not.

Combining batteries with green energy is a fastgrowing climate solution.

“Solar farms only produce when the sun shines, and the turbines only produce when the wind blows,” said Ørsted CEO Mads Nipper. “For us to maximize the availability of the green power, 24-7, we have to store some of it too.”

The United States is rapidly adding batteries, mostly lithium-ion type, to store energy at large scale. Increasingly, these are getting paired with solar and wind projects, like in Arizona. The agencies that run electric grids, utility companies and developers of renewable energies say combining technologies is essential for a green energy future.

Batteries allow renewables to replace fossil fuels like oil, gas and coal, while keeping a steady flow of power when sources like wind and solar are not producing. For example, when people are sleeping and thus using less electricity, the energy produced from wind blowing through the night can be stored in batteries — and used when demand is high during the day.

Juan Mendez, a resident of Tempe, Arizona, gets power from local utility Salt River Project, which is collaborating with Ørsted on the Eleven Mile Solar Center. As a state senator, Mendez pushed SRP to move to renewable energies.

He thinks the power company is still investing too much in gas and coal plants, including a major expansion planned for a natural gas plant in Coolidge, Arizona, near the solar center.

“This solar-plus-storage is a good step, but SRP needs to do more to provide clean energy and clean up our air and help address climate change,” Mendez said.

The utility said it's adding more renewables to its energy mix and recently pledged to zero out its emissions by 2050.

The U.S. has the second most electrical storage in the world, after China. In 2023, the U.S. added an estimated 7.5 gigawatts — 62% more than in 2022, according to the BloombergNEF and the Business Council for Sustainable Energy factbook. That amount can power 750,000 homes for a day, according to BloombergNEF.