How are we doing?
Residential energy use received a thumbs up because it remained low among California counties. Energy consumption in San Diego County was comparable to other major urban coastal counties in California and has remained on a slightly downward trend over the last decade. Residential energy use includes both electricity and natural gas use. Households in San Diego County also use other fuels, such as propane, for space heating and water heating, which are not tracked on this page. Renewable energy sources, mainly solar and wind power, are included in residential energy use and provide energy without greenhouse gas emissions. To learn more about how the San Diego region is leading the State in renewable energy generation, see the Renewable Energy & Storage indicator.
Rating: Improving
Residential energy use remained low among California counties
Statewide, natural gas use per household has been decreasing over the past ten years, especially since 2013. Most household natural gas use is for heating homes in the winter, so annual fluctuations in natural gas use are mainly driven by weather. The drop since 2013 is largely due to California’s warmer winters, and more stringent home appliance and building energy efficiency standards. In San Diego County, natural gas use increased from 2018 but remained lower than in 2013. For other counties shown in the chart, the natural gas use per household decreased slightly, 1% to 2%, from 2019 to 2020. San Diego homes have the lowest natural gas use among the counties shown in the chart, most likely due to the milder climate.
The San Diego County average annual electricity use per household increased 11% from 2019 to 2020, from 5,729 kWh to 6,375 kWh. Other comparison counties also showed an increase in electricity use from 2019 to 2020, ranging from a 5% to 11% increase. One potential reason could be the COVID Stay at Home Order issued by Governor Newsom in March 2020. The household electricity use in San Diego County is similar to that in Santa Clara County and San Luis Obispo County. Fresno homes have the highest electricity use on average, around 9,700 kWh in 2020, while San Francisco homes have the lowest electricity use on average, around 4,000 kWh in 2020.
The combined use of electricity and natural gas offers a full picture of household energy use over time. Once converted to the common unit MMBtu (Million British Thermal Units), the total residential energy use (electricity + natural gas) can be compared across counties. Homes in Fresno County had the highest residential energy use in 2020 with 51% from natural gas. San Francisco County’s total residential energy use is comparable to San Diego County, but homes in San Francisco County rely on natural gas more than homes in San Diego County. San Diego County has the lowest total energy use among the counties in the chart, most likely due to our milder, year-round climate.
San Diego County residential electricity use spikes during late summer with a smaller peak in December and January. In summer months, electricity used for air conditioning increases. Electricity used for cooling is impacted by minimum and maximum temperatures, as well as how hot the temperature is on a given day or a period of days. Cooling degree day (CDD) is an indicator of how hot it is on a given day or over a period compared with a base temperature of 65 F, the temperature at which most individuals do not need heating or cooling to be comfortable. Based on the National Weather Service data, the number of CDDs in San Diego County from July through September 2020 was 722, compared with 739 CDDs during the same three month period in 2021.
Why is residential energy use important?
High quality of life means the region boasts a thriving economy, a healthy environment, and an equitable place for all San Diegans to grow and prosper.
Economy
Although California has some of the highest residential electricity rates in the country, California ranks the sixth lowest in residential electricity burden among all states thanks to decades long energy efficiency policies and its climate. Similarly, while the San Diego utility SDG&E has among the highest electricity rates in the country, electricity use is relatively low in San Diego County compared to other regions in the state.
Environment
Reducing the use of fossil-fuel-based electricity and natural gas reduces indoor and outdoor pollutants and their negative impacts on public health and the environment. This will reduce the effect of climate change on future generations.
Equity
Any increases in residential building energy bills will have disproportionate effects on communities with high concentrations of poverty, where people are less likely to be able to afford the increasing costs of electricity bills or lack access to air conditioning. As extreme heat events increase in frequency and intensity in the entire region, requiring greater use of air conditioning, conserving home energy through more efficient buildings, better designed greener communities, and access to cooling centers will help keep bills low and improve the quality of life for all communities.
Regional Response
Policies
The City of Chula Vista adopted a Building Energy Saving Ordinance in 2021 that makes building energy performance data available to existing and prospective owners and leasers. The ordinance requires properties that are 20,000 square feet or larger to submit an energy benchmarking report annually and implement energy improvements every ten years beginning in 2027 or 2030, depending on the building square footage.
Projects
The University of California, San Diego (UCSD) has a goal of reducing its energy use by 2% per year at each campus. One of the projects contributing to this goal is a computerized Energy Management System connecting all major campus buildings and centrally monitoring and controlling energy use based on occupancy. This helps reduce energy use during evenings, weekends and holidays. Similar energy management system projects are underway in the County of San Diego.
Partnerships
The San Diego Regional Climate Collaborative launched their Energy Education and Resource Hub for the San Diego Region (Energy Education Hub). The Energy Education Hub uniquely provides a regional lens to the energy education and resource materials available from statewide and local partners. Information can be found on current and future energy codes and standards, code compliance and performance improvement, local reach code data, zero net energy initiatives, and regional case studies. This program is funded by California utility customers and administered by San Diego Gas & Electric Company (SDG&EⓇ) under the auspices of the California Public Utilities Commission.
University of San Diego efforts & projects
In 2020, the University of San Diego (USD) partnered with an engineering team led by Willdan, Inc. to create an Energy Master Plan (EMP) to achieve carbon neutrality for campus energy use. From February 2020 through April 2021, USD and Willdan worked to produce a comprehensive document to reduce campus energy consumption through efficiency and conservation measures, add on-site renewable generation and energy storage, and replace natural gas fueled equipment with electric versions, thereby eliminating almost all carbon emissions from campus energy use. The EMP also calls for residual emissions to be offset, unless cost-effective measures to eliminate these projected remaining emissions are developed. Not only do these strategies guide USD to achieve carbon neutrality from its energy use, over the 14 year timeframe for implementation, the EMP is projected to save the university almost $8 million. Resilience measures, primarily in the form of cleaner, reliable backup power options are also included, as is an expansion of electric vehicle infrastructure.
Finally, as part of developing the EMP, the USD team emphasized the importance of including students in both the production and implementation of various aspects of the strategy. USD and the Willdan team created internships for two engineering students to assist in research and data analysis for the EMP. Further, the final EMP has an entire section devoted to potential projects that USD students could implement to help establish the EMP, starting in 2021.
What are we tracking?
We measure residential energy use by tracking average annual electricity use and natural gas use per household in San Diego County. We compare that regional consumption to other California counties on an annual and monthly basis.