Dive Brief:
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High costs have scuttled a pumped storage project being planned by the Sacramento Municipal Utility District (SMUD).
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The California municipal utility said the estimated cost of the 400 MW project rose to $1.45 billion from $800 million in 2010.
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SMUD said it is considering several other options to meet its energy storage needs, including compressed air storage, microgrids, small natural gas-fired plants, lithium-ion batteries or a new transmission line as the muni moves away from large, central power plants to incorporate more distributed energy resources.
Dive Insight:
Pumped storage would seem to be the obvious choice for a lot of energy storage needs. It can store a lot of energy by pumping water up to a reservoir that can then release that water quickly for extended periods, without the life-cycle restraints of batteries. But pumped storage is meeting competition from newer technologies as result of high capital costs and siting and permitting challenges.
Both were factors in SMUD’s recent decision to cancel a planned 400-MW pumped storage project that was designed to help the municipal utility deal with the increasing amount of solar and wind resources on its grid.
SMUD’s original cost estimate for the project, back in 2010, was $800 million, but over time it rose to $1.45 billion. In 2015, SMUD re-evaluated the project and determined that it would be need only about half of the project’s 400-MW capacity until 2030 or later.
On the environmental front, SMUD has planned to fit the project inside a mountain in order to minimize noise and visual effects on the surrounding countryside. The hydro project was set to be built at Slab Creek Reservoir in El Dorado County east of Sacramento County. But boring the required tunnels would have created a flow of groundwater that the State Water Resources Control Board wanted SMUD to monitor for an entire calendar year.
SMUD concluded that the project was not financially feasible. And, in a statement, said that with recent advances in other energy-storage technologies, it is likely there will be more economical alternatives for satisfying Sacramento's energy storage needs in the long term.