Monday, May 13, 2019

USA, California: The Case for Geothermal Energy in a Diverse Portfolio of Renewable Sources

Geothermal balances California’s renewable portfolio (Renewable Energy World)

Geothermal Energy the savior of Salton Sea, by Alexander Schriener Jr. Units 1 and 2 at Salton Sea geothermal field, Imperial Valley Ca. View from Obsidian Butte looking south across the declining Lake. Dead tree has Blue Heron nests. Taken 26-Dec-13. GRC Photo Contest 2016.

By V. John White, executive director of the Center for Energy Efficiency & Renewable Technologies (CEERT) and Nick Goodman, Chairman and CEO of Cyrq Energy, Inc.

California’s rapid renewable energy expansion has led to a boom in large-scale solar and wind projects and a huge expansion of rooftop solar. As costs have fallen, solar energy has become much less expensive, and utility-scale solar and wind are now less expensive than new gas plants, and far less expensive than existing coal. 

Geothermal energy has historically been a large part of California’s renewable energy portfolio, but its role in California’s renewable power supply has steadily declined. California utilities have contracted for virtually no new geothermal as part of their push to comply with the California 50 percent renewable portfolio standard.

The reasons most often cited for why geothermal has been left behind are that it costs more than solar or wind and utilities’ principal goal in building their renewable portfolios is to minimize their cost of complying with the state renewable standard.

California’s RPS program has been widely hailed as a success and yet the resulting renewable portfolio is unbalanced. That’s partly because of the program’s focus on minimizing cost. Even though solar has the lowest levelized cost of energy, because of how much solar we already have on the system, with more being added every year, the incremental value of additional solar is less than at lower penetration levels. In addition, in the Spring and other times of year, the abundance of solar leads to negative pricing on the grid, and the curtailment of thousands of megawatts of solar and other renewables, resulting in lost revenue for renewable projects and higher costs for consumers. 

In addition to helping provide much needed balance to California’s renewable portfolio, geothermal can provide valuable grid reliability benefits, which mistakenly, are not considered by the Public Utilities Commission when implementing the renewable portfolio standard. Because geothermal plants use traditional spinning generators and produce power around the clock, they can reduce reliance on natural gas for reliability. A vivid example is found in the most recent Transmission Plan adopted by the California Independent System Operator (CAISO), which showed that abundance of solar and lack of geothermal generation (or any type of energy storage) in the Imperial Valley to the East of San Diego results in continued reliance on natural gas plants to provide reliability when the sun goes down, resulting in higher costs and increased emissions.