The percentage of total power mix (in-state generation plus imports) from renewable sources rose 0.5 percent to 33.6 percent in 2021. At the current pace of growth, California is at risk of missing the 50 percent Renewable Portfolio Standards (RPS) goal by 2026.

Electricity generation from renewables exceeded 93,000 gigawatt-hours (GWh) in 2021, but has not significantly increased since 2018. The increase in total RPS percentage is due to the decrease in imports from natural gas—9.1 percent lower than in 2020 and 11.2 percent lower than in 2019—resulting in an overall 45 percent decrease from 2020, and offsetting the smaller increase captured in the in-state generation sector. For reference, California imported in total of 7,925 GWh from natural gas from other states in 2021.

The ongoing drought significantly hampers electricity generation from hydroelectric. Small hydro’s share of generation in 2021 (1% of generation mix) is one of the lowest since the RPS program’s inception in 2002. Ongoing generation from hydroelectric is expected to remain low, as long as the drought persists, and California will likely be forced to buy more power from neighboring states.

Despite having a similar share of renewables, imports from the Southwest are more carbon intensive due to their higher percentage of generation from coal (17% in 2020) compared to Northwest imports (0.5%) and in-state generation (0.2%).

Electricity generation from RPS-eligible renewable sources and large hydroelectric made up 42.9 percent of the power mix in 2021, a slight decrease from the 45.3 percent in 2020 and 46.3 percent in 2019. Electricity generation from these sources made up 34.8 percent of total in-state generation in 2021—a significant decrease from 33.3 percent in 2020. Both decreases are mainly due to the drought. Both decreases are mainly due to the drought.

Of the utility-scale power plants that came online after 2010, California added more capacity from solar than any other sources. As of May 2021, the power plant additions primarily came from solar and wind, at 0.9 and 0.3 gigawatts (GW) respectively, while the power plant retirements solely came from solar resources at 0.3 GW.

For California to meet its 2026 goal of 50 percent of generation from RPS-eligible renewable sources, the share of electricity generation from renewables would need to increase by 8.3 percent each year from 2021 to 2026, revised upward from the 6.1 percent annual growth rate previously predicted in 2018.

In 2021, total estimated annual load in Community Choice Aggregations (CCAs) in California increased 1.38 percent over 2020’s annual load, serving over 11 million people in California. One of the oldest members of the CCAs, Marin Clean Energy (MEC), has signed the most long-term energy contracts, committing over 900 megawatts—more than 400 megawatts of its renewable capacity went online in 2020.

In 2021, three community choice aggregators—MCE, East Bay Community Energy, and Silicon Valley Clean Energy—issued $2 billion in bonds to pay upfront for about 450 MW of renewable energy. It is expected to reduce power costs by $7 million a year in the first five to ten years.

Oregon extended and strengthened its previous reduction goals (requiring a 10 percent reduction in average carbon intensity of fuels) to a long-term target of 25 percent of the electricity generated from renewable sources by 2025 and 50 percent by 2040.

Since 2018, the residential sector has experienced the most rebate-qualifying distributed energy resources (DERs), mostly for electrochemical storage technologies (such as lithium-ion battery storage). Previously, commercial and government sectors had the most rebate-qualifying DERs.

Under the Self Generation Incentive Program (SGIP), California added 77.4 kilowatt-hours (kWh) of energy storage capacity across all sectors in 2021, with the government sector adding 46.7 percent of the energy storage capacity. The capacity added in 2021 represents a 56.3 percent decrease over the capacity added in 2018 (116.4 kWh).

In California, both wind and solar curtailments have been rising every year from 2018 to 2022 to-date, driven by growth in the amount of solar power additions to meet the state’s aggressive clean energy goals. As of October 2022, curtailments reached a new high in 2022—totaling 2,356 gigawatt-hours (GWh) of electricity generated with 115 GWh from wind and 2,241 GWh from solar). This is 56.6 percent more than the total amount in 2021, with 57.1 percent more curtailment in solar and 47.5 percent more in wind.

According to S&P Global Market Intelligence, the California ISO (CAISO) is expected to add an additional 9,172 megawatts (MW) of net nameplate capacity measurement units in 2022, largely lithium-ion batteries and solar photovoltaics installed together. Developers intend to add some 2,524 MW of new CAISO-connected battery power capacity in 2022, approximately doubling total installed battery power capacity in 2021. Over the 20-year planning period, more than 6,300 MW of planned solar is expected to come online, as well as 320 MW of wind energy and 60 MW of geothermal.¹²⁴

Interconnected distributed generation within the three investor-owned utilities service territories totaled 1,595 megawatts (MW in alternate current) in 2021, an 18.7 percent increase from 2020. Residential continues to be the largest sector, accounting for 72 percent of the interconnected distributed generation installed (1,148 MW) in 2021. Due to low statewide participation, SGIP increased the incentive in 2020 to encourage new applications.

As of 2021, California accounted for 41 percent of small-scale solar photovoltaic (PV) net generation in the residential sector nationwide. The state also accounted for 31 percent in the commercial sector (which includes government),¹²⁵ and 72 percent in the industrial sector.

In 2021, cumulative installed capacity from wind totaled 6,281 MW in California, an increase of 4.9 percent from 2020 (5,982 MW). Meanwhile, the rest of the nation continued adding wind capacity at a nice pace (12,448 MW) in 2021.

More than 4,000 MW of battery storage has been installed in California ISO territory. The state projects more than 48,000 MW of battery storage and 4,000 MW of long-duration storage will be needed by 2045.¹²⁶

Under California’s landmark 2019 energy storage procurement mandate (AB 1144), investor-owned utilities have already surpassed the 2024 procurement target of 1,325 MW of installed energy storage capacity by 78 percent.

To address grid reliability concerns and incorporate the additional energy, the 20-year transmission infrastructure projects needed in the next two decades have been identified. From the base portfolio 2031 to 2040 (using SB 100 starting point scenario), renewables resources and battery storage are expected to grow by an average of 346 percent, while pumped hydro and long-duration energy storage share the same growth rate of 538 percent and dominate the growth plan.