In Q4 2024, California reclaimed the #1 position for total installed solar capacity, overtaking Texas with more than 50,000 megawatts of capacity. 

• Texas overtook California as the top-ranked state for solar capacity additions for the first time in 2021
• In 2022, California was once again the top-ranked solar market
• In 2023, Texas ranked #1, surpassing California for the second time.

Southwestern states Arizona, Nevada and New Mexico also ranked in the top 15 nationally, with Arizona climbing from #6 to #4 and Nevada from #11 to #6.

This shift highlights the Southwest’s expanding leadership in solar energy as infrastructure grows and state incentives continue to accelerate adoption.

Why Is Solar Adoption in California So High?

Mandates and Pro-Solar Policies Drive Growth

California’s solar dominance isn’t just about sunshine and high utility costs—it’s also the result of strong legal and regulatory support.

Solar Mandate for New Homes:
Since 2020, all new low-rise homes in California are required to include solar panels, following a 2018 ruling by the California Energy Commission. The mandate expanded in 2023 to cover most new apartments and commercial buildings.

Supportive Regulations:

• The Solar Rights Act prohibits local restrictions on solar installations.
• AB 2188 ensures streamlined permitting for residential solar.
• Net Energy Metering (NEM) policies allow customers to earn credits for excess power, encouraging both solar and battery storage
  (GreenLancer).
• Solar systems are exempt from property tax increases under California law.

These policies have helped push California’s installed solar capacity above 50,000 megawatts, leading the nation by a wide margin.

Sources & Methodology

This report draws from publicly available data published by the U.S. Energy Information Administration (EIA) and the Solar Energy Industries Association (SEIA). The analysis incorporates the most recent data available as of Q1 2025.

Electricity Reliability

To assess grid reliability across states and utility providers, we used 2023 data from Form EIA-861, which is released annually by the EIA. This dataset includes two core reliability metrics:

• SAIFI (System Average Interruption Frequency Index): Measures how often the average customer experiences a non-momentary power outage in a calendar year.
• SAIDI (System Average Interruption Duration Index): Measures the total duration of non-momentary outages experienced by the average customer over the same period.

Both metrics were analyzed at the state level and for individual utility providers in California. Because outage duration is reported in minutes, we converted all SAIDI values into hours to improve readability. Note: 2024 SAIFI and SAIDI data will not be available until October 2025; therefore, this report relies on 2023 figures—the latest year for which complete data exists.

Electricity Prices

We analyzed residential electricity prices by comparing statewide average prices per kilowatt hour (kWh) for February 2024 and February 2025, as reported by the EIA. These monthly averages were used to calculate the year-over-year percentage change in electricity pricing at the state level.

Solar Adoption

Solar generation data was sourced from the SEIA’s publicly released quarterly reports, current through Q4 2024. Three key solar adoption metrics were included:

• The percentage of each state’s electricity generated from solar
• Each state’s national ranking in total installed solar capacity (both for 2024 and 2025)
• The total number of megawatts (MW) of solar capacity installed by state