By Mike O'Boyle and Priya Sreedharan
On April 30, California’s grid set a new record when it produced enough carbon-free energy to meet 100 percent of electricity demand for over six hours. These records will only become more common as California marches forward on clean energy. As California embraces renewables and transitions away from fossil power, the state must maintain and enhance grid reliability with these resources that have very different characteristics, and at the same time face the realities of increasing heat, drought, and wildfires.
New research from GridLab, Telos Energy, and Energy Innovation shows California can go big on clean energy, hitting 85 percent clean electricity by 2030 while maintaining our grid’s reliability. These findings exceed the current 2030 target in SB 100, and show the State Senate’s newly proposed targets of 90 percent by 2035 and 95 percent by 2040 are within reach.
But targets aren’t enough – policymakers and the utilities they regulate should diversify California's clean energy mix, insulating residents from reliability risks as we transition to this clean energy future.
The research tested three possible pathways to see how California could achieve an accelerated 85 percent clean target using the same planning tool state agencies use. A base portfolio tested the reliability of a least-cost portfolio with heavy reliance on solar and storage. A second portfolio tested the benefits of resource diversity by adding adds significant offshore wind and geothermal. A third portfolio explores whether widespread vehicle and building electrification could potentially stress the grid.
We evaluated these pathways marching through every hour of eight different known weather years, to see how solar and wind power generation would perform in each scenario. We then tested the 85 percent clean portfolios against stressors like low hydropower due to drought, retiring roughly one-third of in-state gas, coal retirements across Western states that could threaten our ability to import power, and conditions similar to the heat-wave that caused rotating outages in 2020.
In each of these cases, we found an 85 percent clean California grid could reliably meet our state’s energy needs.
But translating modeling results into the real world is an entirely different task. In February, the California Public Utilities Commission boldly required utilities to procure enough renewables hit 86 percent carbon-free electricity by 2032. How it is implemented will have profound consequences for affordability, reliability, climate, and environmental justice.
Three priorities can help keep us on the path to reliably and equitably hit 85 percent clean by 2030.
First, California must rapidly add new, diverse clean energy resources. While the state must build much more solar, wind, batteries, and transmission lines, we can reduce the risk of supply shortfalls by also adding offshore wind, geothermal, and demand response.
CPUC’s decree requires utilities to rapidly expand clean energy through 2032, mostly solar and batteries. Local, tribal, and state policymakers must collaborate to permit and build this infrastructure quickly while meeting California’s environmental standards. Adding offshore wind and geothermal power would ease siting and transmission burdens, facilitating faster emissions reductions.
Second, the state must retire the gas plants burdening California’s most polluted communities. We’ll still need some gas generation in 2030 to keep the lights, but our analysis indicates an 85% clean system creates room to retire almost a third of remaining gas.
California can eliminate gas entirely if the state plans for solutions that replace that supply. The state has relevant experience – in 2018, the CPUC approved a clean energy portfolio to replace the Puente gas plant expansion in Oxnard. State agencies can replicate this success statewide, prioritizing disadvantaged communities.
Third, California should rely on its neighbors for clean energy when in-state power isn’t enough. California imported 30 percent of its electricity in 2020, which is getting cleaner thanks to clean energy policies in other states. Integrating the state's grid with neighboring states can help provide cheap, clean electricity, but the state should act now. If California waits, other states will likely form their own regional grid, leaving billions in benefits on the table for California consumers.
With federal climate efforts stalling, California must accelerate its clean energy transition to ensure cleaner air, a safer climate, and more reliable electricity for the state's 40 million residents.