Battery-stored solar power sparks backlash from US utilities.

Bloomberg: “California’s three biggest utilities are sparring with their own customers about systems that store energy from the sun, opening another front in the battle that’s redefining the mission of electricity generators.” “Edison International (EIX), PG&E Corp. and Sempra Energy (SRE) said they’re putting up hurdles to some battery backups wired to solar panels because they can’t be certain the power flowing back to the grid from the units is actually clean energy. The dispute threatens the state’s $2 billion rooftop solar industry and indicates the depth of utilities’ concerns about consumers producing their own power. People with rooftop panels are already buying less electricity, and adding batteries takes them closer to the day they won’t need to buy from the local grid at all, said Ben Peters, a government affairs analyst at Mainstream Energy Corp., which installs solar systems. “The utilities clearly see rooftop solar as the next threat,” Peters said from his office in Sunnyvale, California. “They’re trying to limit the growth.” ….Solar systems with batteries attached have gained a foothold in the market as costs fall, allowing customers more flexibility for using their own power at night or when local supplies fail. The systems average about $12,000 to $16,000, adding about 25 percent to the cost of rooftop power plants, according to Outback Power Inc., an Arlington, Washington-based provider of battery-backed solar systems. Matthew Sperling, a Santa Barbara, California, resident, installed eight panels and eight batteries at his home in April. “We wanted to have an alternative in case of a blackout to keep the refrigerator running,” he said in an interview. Southern California Edison rejected his application to link the system to the grid even though city inspectors said “it was one of the nicest they’d ever seen,” he said. “We’ve installed a $30,000 system and we can’t use it,” Sperling said. Utilities say the storage systems open the possibility of fraud. The issue is whether all the electricity being sold through the net metering program is generated only by renewable sources, as required. Consumers in theory can fill the batteries with power from the grid and then send it back designated as renewable energy. With the solar-battery systems, there’s no way to determine the source of the energy. Solar suppliers say that’s not happening. ….The state has set a goal of obtaining 33 percent of its power from renewables by 2020, the nation’s strongest requirement. With more electricity coming from intermittent sources such as wind and sunlight, storage systems will be an important tool to manage the grid. Demand for the systems may grow as prices decline. Battery costs are forecast to fall 57 percent to $807 a kilowatt-hour in 2020 from $1,893 for a kilowatt-hour of storage capacity now, according to data compiled by Bloomberg. The global market for solar systems combined with energy storage will rise to $2.8 billion in 2018 from less than $200 million this year, according to Boston-based Lux Research Inc. About 391 megawatts of solar panels were fitted at customer sites across the state last year, according the California Solar Initiative. The price to install residential projects has declined 15 percent to $3.71 a watt in the second quarter from $4.35 a year earlier according to the Washington-based trade group SEIA.”