The U.S. Environmental Protection Agency gave San Diego props last week for the city’s renewable energy projects at the Point Loma Wastewater Treatment Plant.

The plant generates 27 percent of its energy, or 69 million kilowatt hours, on-site from renewable sources such as recaptured methane gas and hydroelectric generation.

As a result, San Diego was the EPA’s No. 3 green energy partner in the United States behind Kimberly-Clark Corp., which produces 192 million kilowatt hours on-site from biomasses, and Los Angeles County Sanitation Districts, which produce 171 million kilowatt hours from biogas sources.

The EPA’s Green Power Partnership works with more than 1,100 organizations that produce or purchase more than 16 billion kilowatt hours of green power annually, equivalent to the carbon dioxide emissions from electricity use of more than 1.6 million American homes.

The city wastewater treatment plant generates 4.57 megawatts of electricity through methane gas, 1.35 megawatts by hydroelectricity from the 100-foot drop of treated sewage to the ocean and 1.2 megawatts from a converted diesel generator that runs on 80 percent digester gas and 20 percent diesel fuel, which is the first of its kind, the EPA said.

One megawatt of electricity can power 1,000 homes.

Number four on the list is San Jose/Santa Clara Water Pollution Control Plant, which produces 56 percent green power on-site; San Francisco, which runs on 3 percent green power; Wal-Mart Stores in California and Texas, which generate 8 percent green power; Macy’s California and Hawaii stores, which generate 3 percent green power; Safeway in Pleasanton with 3 percent green power, and Alameda County facilities with 11 percent green power.

“These companies are leading a nationwide move to the clean-energy economy, one that can create millions of jobs, reduce our dependence on foreign oil, and protect against global climate change,” said EPA administrator Lisa P. Jackson.

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Eco-Friendly Batteries Tap Green Market: Rechargeable battery manufacturer PowerGenix has put its own brand on AA nickel-zinc rechargeable batteries, the San Diego company announced July 28.

Four-packs with a charger priced at $34.99, and $14.99 without a charger, will be sold online at Amazon.com, GreenBatteries.com and DepotEco.

PowerGenix’s nickel-zinc AAs deliver power on par with single-use nickel-cadmium and nickel metal hydride batteries. That, says the company, is a 30 percent improvement over conventional AA rechargeable batteries.

“With the first true replacement for disposable battery technology, PowerGenix is focused on offering a better battery alternative and expanding rechargeables’ share of the $5.2 billion global consumer market,” said Dan Squiller, CEO of PowerGenix.