California’s RPS mandate, formally the Renewables Portfolio Standard, requires every company that sells electricity to retail customers in the state to source a growing percentage of that electricity from certified renewable resources, climbing to 60% by the end of 2030 and feeding into the broader goal of a 100% carbon-free grid by 2045. The rule is set out in Public Utilities Code Section 399.11 and the sections that follow it, and it applies to private utilities, community choice programs, competitive electricity sellers, and municipal utilities alike.1California Legislative Information. California Public Utilities Code 399.11 – California Renewables Portfolio Standard Program
The Binding Targets
Senate Bill 100, signed in September 2018, set the procurement schedule that providers actually have to meet. Under SB 100, eligible renewables must supply 44% of retail sales by the end of 2024, 52% by the end of 2027, and 60% by December 31, 2030.2California Legislative Information. Senate Bill 100 – California Renewables Portfolio Standard Program The statute also expresses the Legislature’s intent to reach 50% by December 31, 2026, between those two binding milestones.
SB 100 added a longer-horizon policy goal on top of the RPS: 100% of California’s retail electricity from renewable and zero-carbon resources by December 31, 2045.3California Energy Commission. SB 100 Joint Agency Report That 2045 figure is broader than the RPS, because it counts carbon-free sources like large hydroelectric and nuclear that don’t qualify as “eligible renewables” under the RPS itself. The RPS gets the state to 60%; other carbon-free generation is expected to fill the rest.
Who Has to Comply
The mandate covers essentially every load-serving entity selling power to end-use customers in California:
- Investor-owned utilities such as Pacific Gas & Electric, Southern California Edison, and San Diego Gas & Electric.
- Community choice aggregators, the local-government bodies that procure power on behalf of residents and businesses in their territory while the host utility continues to deliver it.
- Electric service providers, the third-party sellers operating in competitive segments of the market.
- Publicly owned utilities, meaning municipal and other publicly owned systems.
Oversight is split between two agencies. The California Public Utilities Commission handles compliance for investor-owned utilities, community choice aggregators, and electric service providers.4California Public Utilities Commission. Renewables Portfolio Standard Program and Compliance Information for New California Load-Serving Entities The California Energy Commission enforces the standard against publicly owned utilities. Some small publicly owned utilities with distribution demand below a specified threshold may qualify for modified requirements or exemptions under the governing regulations.5Legal Information Institute. California Code of Regulations Title 20 3204 – RPS Procurement Requirements
What Counts as Eligible Renewable Energy
The California Energy Commission certifies individual generating facilities based on their technology, size, and location. The qualifying resource categories are:
- Solar, both photovoltaic and solar thermal.
- Wind, onshore and offshore.
- Geothermal.
- Biomass and biogas, including landfill gas and other organic-waste feedstocks.
- Small hydroelectric, meaning facilities of 30 megawatts or less.1California Legislative Information. California Public Utilities Code 399.11 – California Renewables Portfolio Standard Program
- Ocean energy, including wave and tidal current.
- Fuel cells running on qualifying renewable fuels.
The 30-megawatt cap on hydro is one of the most consequential lines in the whole program. Large hydroelectric dams, despite producing emission-free power, do not count toward RPS percentages. Neither does nuclear. Both can be credited toward the 2045 goal of a fully carbon-free grid, but neither helps a utility hit its RPS number. A provider with a big portfolio of large hydro or nuclear still has to go procure separately from RPS-eligible sources.
Most eligible facilities also have to interconnect within the Western Electricity Coordinating Council service territory, which spans the western United States and parts of Canada and Mexico, so that the generation feeding California’s RPS is tied to the same regional grid.
How Compliance Is Proven
The entire system runs on Renewable Energy Credits, or RECs. One REC represents the environmental attributes of one megawatt-hour of electricity generated by an eligible renewable facility.6U.S. Environmental Protection Agency. Renewable Energy Certificates When a qualifying wind or solar project produces a megawatt-hour, a REC is created, and the utility that ultimately owns it must formally retire it to claim credit toward its RPS obligation.
California tracks all of this through the Western Renewable Energy Generation Information System, known as WREGIS. Every REC gets a unique serial number, which stops any megawatt-hour from being counted twice. Load-serving entities register the credits they procure and retire them inside WREGIS at compliance time.
Not all RECs are weighted equally. The RPS sorts procurement into three portfolio content categories tied to how directly the renewable generation reaches the California grid, with bundled in-state or directly delivered power at the top and unbundled, standalone credits at the bottom. The law caps how much of a provider’s compliance can come from the lower-tier categories, so a utility can’t satisfy its obligation purely by buying cheap paper credits detached from any electricity delivery.
What Happens If a Provider Misses the Target
Compliance is measured over multi-year periods rather than year by year, which lets providers bank surplus RECs from strong procurement years and apply them against future shortfalls. Each compliance period still has firm targets, though, and missing them has consequences.
For investor-owned utilities, community choice aggregators, and electric service providers, the CPUC is the enforcement authority and has set out penalty rules through a series of decisions.4California Public Utilities Commission. Renewables Portfolio Standard Program and Compliance Information for New California Load-Serving Entities Penalties are calculated per megawatt-hour of unmet obligation and are subject to annual caps that scale with the utility’s size. The money collected flows into the state’s Electric Program Investment Charge Fund for clean energy research and development.
Publicly owned utilities answer to the California Energy Commission on this, not the CPUC. The Energy Commission has authority to refer non-compliance by a publicly owned utility to the California Air Resources Board for further action.
The program also includes safety valves. A provider that can show required procurement would impose unreasonable costs on ratepayers may seek a waiver or delay from the CPUC. Waivers are also available for conditions outside a provider’s control, such as permitting delays or transmission constraints that keep contracted renewable power from being delivered.
What the Mandate Means on Your Electricity Bill
RPS procurement shows up in rates. When a utility signs a long-term contract with a solar or wind project, or buys RECs on the open market, those costs are folded into the price customers pay. The CPUC reviews investor-owned utility procurement plans and sets rates with an eye to meeting RPS targets as cost-effectively as possible.
Early RPS procurement carried real premiums over conventional generation when solar and wind were still expensive. Costs for those technologies have fallen sharply over the past decade, and new renewable contracts are now often competitive with, and sometimes cheaper than, fossil generation. California retail rates remain among the highest in the country, but that’s driven by a mix of factors including wildfire mitigation, grid maintenance, and transmission investments, and separating the RPS’s specific contribution from the rest is difficult. Utilities are required to report their RPS procurement costs in regular compliance filings.
If you’re served by a community choice aggregator rather than directly by the investor-owned utility, your rate structure looks a little different: the aggregator sets the generation rate while the utility still bills for transmission and distribution. Some aggregators market a renewable content higher than the RPS floor, which can carry a small premium for customers who don’t opt out.