Dec 2 (Reuters) – California public power and water company Imperial Irrigation District (IID) proposed to expand its Southern California transmission system to boost the amount of renewable energy it can export to the rest of the state and to the U.S. Southwest.
IID said in a release that the increased exports will help California replace generation lost by the retirement of the San Onofre nuclear power plant, located on the Pacific Coast between San Diego and Los Angeles.
The expansion project could cost $431 million to $1.7 billion, depending on what transmission lines IID builds and what partnerships it establishes with other utilities to share the costs.
IID proposed to recover the costs from companies that take the renewable energy.
IID wants to build a 2,200-megawatt (MW) 30-kilovolt (kV) system to export 1,100 MW to the rest of California and simultaneously export another 1,100 MW to utilities in the Southwest.
One megawatt can power about 1,000 homes.
The project includes the development of a 500-kV alternating current (AC) line rated at 1,200 MW to connect to Arizona Public Service’s territory in Arizona, and the constructionof a 500-kV direct current (DC) transmission line rated at 1,100 MW from the Salton Sea area to a substation at San Onofre.
Arizona Public Service is a unit of Arizona power company Pinnacle West Capital Corp.
IID said it can add more transmission to increase the amount of power it can export from 2,200 MW to 4,100 MW as the need for additional renewable energy occurs.
California is approaching the second renewable portfolio standard compliance period (2014-2016), whereby utilities are required to provide a minimum of 25 percent of the energy from their supply portfolios with renewable resources, IID said.
The final compliance period (2017-2020) requires that amount to increase to a minimum of 33 percent in 2020.
IID said it submitted its plan to the California Independent System Operator (ISO), which operates the power grid for much of California, in November and expects to hear from the ISO by the end of the first quarter of 2014.