Batteries are hot, but utilities looking to store a lot of power may find cheaper options elsewhere
All the talk in the electric utility industry these days seems to be about battery storage, but there are other ways to save generated electricity for later.
With more demanding state renewable portfolio standards, the finalization of the EPA’s Clean Power Plan and utilities increasingly turning to renewables as a least-cost option, grid operators are likely to need more and bigger storage options by the mid-2020s, if not before.
“The excitement in the market now is around the policies we have in place, which very specifically exclude big pumped hydro applications,” explained California Energy Storage Alliance (CESA) Sr. Advisor Mark Higgins, the VP/COO at Strategen Consulting. “Those policies were designed to create a diversity of technologies. Bulk storage would work against that.”
But, Higgins said, by around 2024, when California gets to about 40% renewables, there will be a real need to shift excess renewable energy supplies from the middle of the day to the late afternoon and evening. “That will require storage resources that can handle big amounts of energy over long periods of time.”
Higgins expects California regulators to again take the lead, as they did with the AB 2514 policy now driving battery technology growth, and put in place incentives for long duration storage technologies.
Pumped hydro promises big capacity
Pumped hydro storage (PSH) uses energy to move water from a lower reservoir to a higher reservoir where it can, at need, be released. The energy is recaptured as hydroelectric power as the water flows back to the lower reservoir.
“Pumped hydro’s sweet spot is bulk energy shifting,” Higgins said. “But there are not many good sites left, upfront capital costs are high and policy support is limited.” Such obstacles have limited excitement about pumped hydro’s growth.
Duke Energy, however, says it is excited about pumped hydro, according to Spokesperson Lisa Parrish, because its quick start up time provides flexibility the utility needs. “Pumped storage functions like a giant water battery…At a moment’s notice, the stored water can be used to meet peak demand.”
The potential of Califonia’s Bison Peak 1 and 2 PSH Projects excites Alton Energy President Ed Duggan. Eagle Crest’s Eagle Mountain PSH Project was green-lighted first by the Federal Energy Regulatory Commission (FERC), in hopes of helping fill the gap left by the shuttering of the San Onofre Nuclear Generating Station. But Duggan believes the combined 2,000 MW capacity of the Bison projects will have more benefits if he can get a green light from FERC.
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