Renewable Energy & Storage

How Are We Doing?

Renewable energy and storage received a thumbs up because of increases in distributed solar electricity generation reaching a cumulative of 1.6 gigawatts, the highest among California counties.

We also saw increased uptake of energy storage, both distributed and grid-scale, vital to providing flexibility in the integration of renewables which are intermittent such as solar and wind supply. In 2020, San Diego County saw its highest single year increase of new distributed energy storage projects, with 58 MW of power capacity. 2020 also saw the largest grid-scale lithium-ion battery energy storage project in the world called Gateway Energy Storage, located in East Otay Mesa currently at 250 MW capacity for one hour, which provides power after being charged with solar during the day for the state’s utilities.

Want to know more about what we're measuring?

thumbs up

Installed solar capacity ranked top among California counties

In September 2018, California adopted SB100, the 100 Percent Clean Energy Act of 2018, that increases the current mandated renewables portfolio standard (RPS) from 50% renewables to 60% renewables by 2030 and establishes a state policy of 100% zero-carbon electricity by 2045.

The decrease in renewable content from 2018 to 2019 is due to a revised methodology from the California Energy Commission.The method is revised in order to be consistent with Greenhouse Gas (GHG) accounting method. With this update, if the renewable energy attributes of electricity  (known as renewable energy credits, RECs) are not procured and delivered together to the customers, they will no longer count towards a utilities’ renewable portfolio standard. Previously, a certain amount of RECs could be purchased to effectively offset emissions from grid supply and count towards the utility’s renewable portfolio standard. Now, any unbundled RECs must be reported separately, and they do continue to contribute to greenhouse gas reduction elsewhere. Due to this accounting change, the renewable content in SDG&E’s portfolio changed from 43% in 2018 to 31% in 2019 with an additional 7.8% of SDG&E’s electricity sales covered by unbundled RECs. Of the other two investor-owned utilities (IOUs) in California, PG&E did not have unbundled RECs in 2019 and Southern California Edison (SCE) had 2.9% sales covered by unbundled RECs. All utilities are expected to meet the 33% renewable electricity by the 2020 target.

Apart from the default electricity portfolio offered to customers, all IOUs have programs where customers can select higher renewables at a premium cost. SDG&E’s EcoChoice program for example allows customers to select up to 100% of electricity from renewable sources.

Utility scale energy storage systems, which are large energy storage systems managed by electric utilities (rather than by customers), combined with renewable energy can help utility companies manage energy supply and demand with flexibility and reliability. Under AB 2514, the California Public Utilities Commission set a statewide energy target of 1,325 megawatts (MW) by 2020, and a goal of 165 MW for SDG&E. In 2020, SDG&E was 6 MW short of its target but plans to meet the target by 2021. The other two IOUs, PG&E and SCE, have enough energy storage contracts in place to meet their respective AB1524 targets. 

In 2016, California passed AB 2868 that builds on the previous storage mandate with a requirement for 500 MW distributed behind-the-meter storage.

In the SDG&E service area, which includes San Diego County and a small portion of Orange County, close to 30,000 new solar PV systems were installed in 2020, a decrease of 10% from 2019. All the new systems added 230 MWs of solar capacity. The majority of the new installations and new capacity in 2020, were from residential rooftop solar systems. In 2020, the City of San Diego was ranked second highest among the top major cities in the nation in both the number of solar systems installed per resident and total solar capacity.

San Diego County had the highest total solar capacity among counties in California with over 1.6 GW installed as of December 2020

The California Public Utilities Commission's Self-Generation Incentive Program (SGIP), one of the most successful distributed generation incentive programs in the country since 2001, was modified over the years to complement the transition to a low carbon economy and incentivize distributed energy resources, now including energy storage, that contribute to greenhouse gas reduction goals. In 2017, about 80% of the SGIP incentive funding was allocated to energy storage which is based on several factors, including the kilowatt-hour (kWh) capacity of the system.

This chart shows the number of applications submitted for customer side storage incentives through the Self-Generation Incentive Program (SGIP). SGIP has been helping California lead the nation in residential battery storage deployment by providing an upfront rebate based on the amount of energy stored in the battery. The significant increase in the number of applications and capacity in 2020 was due to an increase in residential battery storage, especially storage coupled with on-site solar systems. Residential battery storage systems represent 95% of the SGIP applications and 44% of the battery capacity in 2020.. 

Why is Renewable Energy & Storage Important?

High quality of life means the region boasts a thriving economy and a healthy environment accessible to all in the community.

  • Environment: Shifting to renewable energy is one of the main strategies for avoiding future greenhouse gas emissions and improving air quality. When coupled with energy storage, renewable sources provide a continuous energy supply, increasing system reliability and cost-effectiveness.
  • Economy: This analysis shows the 2019 building energy efficiency standard’s PV requirement will save families thousands of dollars over the first decade of ownership. The reduction in energy bills due to the solar PV system exceeds the corresponding increase in mortgage payment, by around $35 per month on average.
  • Equity: Distributed generation, small-scale renewable technologies that produce electricity close to the end user, makes the region more resilient to power outages. Power outages, including the prevalence of Public Safety Power Shutoffs (PSPS) during the 2019 wildfire season throughout the state, led to 60% of the new expanded Self Generation Incentive Program being dedicated to “Equity Resiliency” projects for low-income customers, those who live in high fire risk area, those who experienced PSPS events on two or more distinct occasions, and critical facilities that provide services to these affected areas. These incentives are expected to cover the entire installed cost of any residential energy storage system available.

Regional Response


In the San Diego region nearly all recent Climate Action Plans have measures mandating photovoltaic (PV) systems that are additional to state policies promoting distributed generation. This demonstrates availability of increased capacity for distributed generation and potential for more local generation.


In 2021, the City of San Diego contracted with Shell New Energies to build renewable energy microgrids, at eight municipal facilities, including recreation centers, police and fire stations. Renewable energy microgrids are PV systems combined with batteries that can reduce utility cost and increase power reliability. The PV systems will power the facilities and in the event of power shutoff, the battery systems will provide electricity.


The most recent major regional response to accelerating renewables use for electricity generation comes from the development of Community Choice Energy programs (CCE) which are locally run joint power authorities with typically higher renewables targets than IOUs.

Two CCEs were launched in 2021. The San Diego Community Power (SDCP), launched in March 2021, is currently serving municipal and commercial customers in the cities of Chula Vista, Encinitas, Imperial Beach, La Mesa and San Diego. SDCP will start serving residential customers in early 2022. The Clean Energy Alliance, launched in May 2021, serves the cities of Carlsbad, Del Mar and Solana Beach. 

Residents and businesses in these cities are automatically enrolled in the CCE programs with a more renewable energy alternative than the current utility, SDG&E.

What Are We Measuring?

We measure renewable energy by tracking the number and capacity of new solar installations and the increase in incentivized energy storage projects in the SDG&E service territory. We also track the historical trend of renewable energy as a percentage of SDG&E sales, as well as the progress of SDG&E meeting its energy storage targets. Learn more about the data.