Rancho Seco Solar Facility

Opportunity

Plentiful sunlight, favorable regulation, and high-tech expertise have made California a leader in solar electric power. In 1984, the Sacramento Municipal Utility District (SMUD) created the first utility-scale solar array.

Thirty years later, SMUD has completed a new ten-megawatt solar plant in Herald, CA. Built on the site of a decommissioned nuclear power plant, the Rancho Seco solar plant generates more than 22,000 megawatt-hours of power each year, made available through SMUD’s Commercial SolarShares program.

Solution

Using SKM and ETAP software, Mott MacDonald analyzed the adequacy of the proposed electrical system. We provided load flow analysis for various plant generation levels, a short circuit study, insulation coordination study, current transformer saturation study, cable sizing and ampacity study, arc flash analysis, system protection and coordination study, harmonic analysis, and voltage flicker study.

Outcome

Commissioned in 2016, the solar plant was expected to provide about 85% of the power for the Golden 1 Center, the home of the Sacramento Kings.

According to Frankie McDermott of SMUD, “This project will further enhance the renewable aspect of our power mix, which is already about 50% non-carbon-emitting, helping us meet our Board of Directors’ and the state’s carbon objectives.”