by Steve Haner

An inconvenient truth of utility-scale battery operations is that they take in more power than they later put out. From an energy grid operations point of view they are considered โnet loadโ and certainly not a generation asset.ย
In a previous post about the battery mandate legislation now poised for passage in both the Virginia Senate and the House of Delegates, a national energy laboratory was cited as reporting the batteries lose about 15 percent of stored energy on one โround tripโ, a charge-discharge cycle. For every 100 megawatt hours stored, they can later discharge 85 megawatt hours.
A local energy engineer then contacted Baconโs Rebellion to argue that the efficiency figure is worse than that.ย He came armed with actual performance data on North Carolina and Virginia utility scale batteries from 2020 to 2024, culled directly from U.S. Energy Information Agency public data.ย
Of the 36 battery installations tracked, 33 were in North Carolina, which is ahead of Virginia in using both solar power and related battery backup facilities.ย The utilities report to EIA how much power the batteries took off the grid over the year, and how much they put back in when called upon.ย
(more…)










