Georgia Power's 20% Battery Rating Tilt Could Hand Gas Its Next 6,000 MW

By Priya Raman

Georgia Power is scoring battery storage at just 20 percent in its 2032-2033 procurement. That is the number to watch. By comparison, the utility's own earlier math implied a value near 75 percent.

The state's largest utility wants to add 2,000 to 6,000 megawatts of new capacity for 2032 and 2033. Gas and batteries are both on the table. How each resource counts, though, hinges on a planning metric called Effective Load Carrying Capability, or ELCC — the share of a project's nameplate capacity a utility deems reliably available at peak demand.

Natural gas plants typically score 60 to 80 percent ELCC. Unpaired solar and wind range from 4 to 40 percent. Batteries lift renewables toward 95 percent, though that value erodes as more storage crowds the grid.

Why does the drop from 75% to 20% matter?

A 1,000-megawatt battery project now earns credit for only 200 megawatts of capacity. A 1,000-megawatt gas plant at 80 percent ELCC earns 800. Developers must build four times the battery capacity to match gas on paper.

Georgia Power's previous filings set battery ELCC at 95 percent for the first 3,000 megawatts, 75 percent for the next 3,000 and 50 percent for the 3,000 after that. The utility has not explained what changed. A representative said only that calculations "have been consistent" and that the company is "in the middle of several ongoing resource procurements and cannot comment on specifics of requests for proposals."

That is not an explanation. It's a deflection, and regulators should press for the modeling behind the revision.

Bob Sherrier, an attorney with the Southern Environmental Law Center and the Advanced Power Alliance, called the change a "thumb on the scale for gas." He testified on the issue before Georgia regulators.

"Batteries are going to look significantly more expensive than gas," Sherrier said. "We know that is not the case anymore."

What did the last procurement build?

For 2029-2031, Georgia Power planned nearly 10,000 megawatts of new capacity. Roughly 6,000 megawatts came from natural gas, with solar and batteries filling the rest. At that 2024 planning stage, batteries still carried a 95 percent ELCC on the first tranche.

More than 6,000 megawatts of gas, run at full output year-round, would emit an estimated 20 million metric tons of CO2-equivalent annually — roughly the emissions of 4 million cars. If the 2032-2033 round lands gas-heavy, the utility locks in millions more tons.

Cost data complicates the gas case. Recent estimates show utility-scale solar undercutting new gas generation; adding storage raises the price but stays competitive. Attribute the cost claims to analysts — they are estimates, not settled figures. Still, a 20 percent ELCC makes batteries look costlier on capacity metrics regardless of what they cost to build.

Is the fight over?

Not yet. Georgia Power is reviewing proposals now, with the 20 percent figure still in force. The utility and regulators are expected to debate which projects advance early next year. Selected projects go to regulators for approval in mid-2027.

Sherrier worries some damage is already done. A low ELCC may have deterred battery developers from bidding at all — a chilling effect nobody can measure until the project list lands.

If the metric survives this round, SELC and the Advanced Power Alliance plan to push a higher ELCC in the next planning cycle, expected to begin in 2028.

The watch item: the mid-2027 regulatory filing, where the ELCC's real cost — in lost storage bids — becomes visible.