Clean firm power is the key to affordable, reliable grid decarbonization in California

California has ambitious efforts underway to decarbonize our electric grid by 2045. The choices we make today will help determine how affordably, equitably and reliably we can get there.

Renewables are an important piece of the puzzle, but we will also need something else. Renewable energy supplies can drop up to 60% between summer and winter months, due to cloudier skies and less-powerful winds. Short duration storage batteries can complement renewable generation production on a day-to-day basis, but they cannot pull the state through several weeks of reduced supply.

According to a recent study published in the journal Issues in Science and Technology, California will need to increase its renewable energy generation capacity while also tapping into clean firm power resources to meet these goals.

According to the study, California can fully eliminate carbon emissions without markedly increasing the cost of electricity or undermining the reliability of service. The study considers how much infrastructure would be required, how quickly the state would need to build it and how much land would be needed.

And while each model approached the challenge differently, the study finds costs can be contained (between 7 and 10 cents per kilowatt hour) if the state makes strategic investments into clean firm power resources. However, if the state invests only in renewables and short duration batteries, then generation and transmission rates could more than double under the same time frame.

That is because California would have to significantly over-build the amount of renewable infrastructure, which represents a challenge both in terms of cost and availability of land.

Invest now in clean firm technology

The study suggests that while California develops its interim plan for 60% renewable energy by 2030 it should also plan for roughly 30 gigawatts of clean firm capacity by 2045. This would give policymakers plenty of flexibility, so they can evaluate a variety of options to meet our goals. For example, the state should ensure there is a market signal available for clean firm power technologies including but not limited to:

• Retrofitting existing natural gas generators with carbon capture and storage technology.
• Zero-carbon fuels (biomethane, synthetic methane, hydrogen or ammonia from carbon-neutral processes).
• Conventional and enhanced geothermal energy technologies.
• Biomass with carbon capture and storage.
• New imported nuclear energy.

Each of these technologies may look more expensive today but will keep consumer costs in check over time. The state needs to think holistically about total system cost because, as indicated by the study, portfolios that include at least one clean firm power option would be 32-53% cheaper than a renewable energy and batteries-only portfolio.

Coordination, collaboration essential to success

Decision makers must engage with a variety of stakeholders to make this transition reliable, affordable and equitable. We do not have time to waste. Clean firm power investments do not have the same track record in California as other technologies and therefore will require more coordination. This coordination includes pending actions at a variety of energy agencies and the legislature — consistency will be critical.

As always, we also need to consider how the investments impact the local community from an environmental justice perspective. We should actively consider strategies to uplift the most vulnerable parts of the state by leveraging clean energy investments. Like all technologies, clean firm power sources come with tradeoffs, we need to engage with local groups to determine how these changes will affect residents. We cannot afford to ignore the needs of historically marginalized communities in our quest for a carbon-free grid.

California can fully decarbonize its grid (and go further than what was suggested last month in the joint agency reports). The state’s current plan relies on fossil generation units as a way to maintain grid reliability; clean firm power investments displace those polluting units. These investments will also keep overall rates affordable, maintain grid reliability, create jobs and establish a viable roadmap for other states seeking to decarbonize their grid. California should switch its trajectory to fully decarbonize the electric grid, which requires a long-term vision and some near term actions.

This summer, some of the actions being considered to decarbonize the electric gid include decision points at the California Public Utilities Commission’s integrated resource planning dockets; the Scoping Plan at the California Air Resources Board; the electricity demand forecast at the California Energy Commission; and the newly announced California Independent System Operator’s long-term transmission planning docket.

The state’s leadership should recognize that being smart about these investments now will yield large dividends in the years to come.