The board of directors at Sacramento Municipal Utility District has decided not to proceed with construction of the 400-MW Iowa Hill pumped-storage hydro project.
SMUD says the project was canceled due to cost and financial risks, with the decision taken based on a predetermined cost-based off ramp.
The project was to be built at the existing Slab Creek Reservoir in El Dorado County and involve construction of a new Iowa Hill Reservoir. Iowa Hill was to be an off-stream powerhouse containing three 133-MW pump-turbine units.
Cost estimates were $1.45 billion. “An investment that size would significantly limit the choices SMUD has with regard to future distributed generation technologies and significantly constrains SMUD’s future capital investments,” a press release says.
By contrast, in March 2007, cost estimates to build this project were $520 million.
In 2015, the utility re-evaluated the need for the energy storage that would have been provided by the Iowa Hill project and determined that less than half of the total capacity would be needed before 2030. After further analysis, SMUD concluded the project was not financially feasible and “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.”
Other technologies SMUD is evaluating include compressed-air energy storage, microgrids and small, flexible generating units fueled by natural gas.
SMUD says the decision to cancel the Iowa Hill project will not affect some planned upgrades to Slab Creek Dam.
In November 2006, HydroWorld.com reported that SMUD had reached agreement in principle with parties to allow relicensing of the 647.736-MW Upper American River hydroelectric project, with the addition of a proposed 400-MW Iowa Hill pumped-storage development. The Upper American River project features 11 reservoirs and eight powerhouses.