Solar Footprints in California

This GIS dataset consists of polygons that represent the footprints of solar powered electric generation facilities and related infrastructure in California called Solar Footprints. The location of solar footprints was identified using other existing solar footprint datasets from various sources along with imagery interpretation. CEC staff reviewed footprints identified with imagery and digitized polygons to match the visual extent of each facility. Previous datasets of existing solar footprints used to locate solar facilities include:

GIS Layers: (1) California Solar Footprints, (2) UC Berkeley Solar Points, (3) Kruitwagen et al. 2021, (4) BLM Renewable Project Facilities, (5) Quarterly Fuel and Energy Report (QFER)

Imagery Datasets: Esri World Imagery, USGS National Agriculture Imagery Program (NAIP), 2020 SENTINEL 2 Satellite Imagery, 2023

Solar facilities with large footprints such as parking lot solar, large rooftop solar, and ground solar were included in the solar footprint dataset. Small scale solar (approximately less than 0.5 acre) and residential footprints were not included. No other data was used in the production of these shapes. Definitions for the solar facilities identified via imagery are subjective and described as follows:

Rooftop Solar: Solar arrays located on rooftops of large buildings.

Parking lot Solar: Solar panels on parking lots roughly larger than 1 acre, or clusters of solar panels in adjacent parking lots.

Ground Solar: Solar panels located on ground roughly larger than 1 acre, or large clusters of smaller scale footprints.

Once all footprints identified by the above criteria were digitized for all California counties, the features were visually classified into ground, parking and rooftop categories. The features were also classified into rural and urban types using the 42 U.S. Code § 1490 definition for rural. In addition, the distance to the closest substation and the percentile category of this distance (e.g. 0-25th percentile, 25th-50th percentile) was also calculated. The coverage provided by this data set should not be assumed to be a complete accounting of solar footprints in California. Rather, this dataset represents an attempt to improve upon existing solar feature datasets and to update the inventory of "large" solar footprints via imagery, especially in recent years since previous datasets were published.

This procedure produced a total solar project footprint of 150,250 acres. Attempts to classify these footprints and isolate the large utility-scale projects from the smaller rooftop solar projects identified in the data set is difficult. The data was gathered based on imagery, and project information that could link multiple adjacent solar footprints under one larger project is not known. However, partitioning all solar footprints that are at least partly outside of the techno-economic exclusions and greater than 7 acres yields a total footprint size of 133,493 acres. These can be approximated as utility-scale footprints.

Metadata: (1) CBI Solar Footprints

Abstract: Conservation Biology Institute (CBI) created this dataset of solar footprints in California after it was found that no such dataset was publicly available at the time (Dec 2015-Jan 2016). This dataset is used to help identify where current ground based, mostly utility scale, solar facilities are being constructed and will be used in a larger landscape intactness model to help guide future development of renewable energy projects. The process of digitizing these footprints first began by utilizing an excel file from the California Energy Commission with lat/long coordinates of some of the older and bigger locations. After projecting those points and locating the facilities utilizing NAIP 2014 imagery, the developed area around each facility was digitized. While interpreting imagery, there were some instances where a fenced perimeter was clearly seen and was slightly larger than the actual footprint. For those cases the footprint followed the fenced perimeter since it limits wildlife movement through the area. In other instances, it was clear that the top soil had been scraped of any vegetation, even outside of the primary facility footprint. These footprints included the areas that were scraped within the fencing since, especially in desert systems, it has been near permanently altered. Other sources that guided the search for solar facilities included the Energy Justice Map, developed by the Energy Justice Network which can be found here:

https://www.energyjustice.net/map/searchobject.php?gsMapsize=large&giCurrentpageiFacilityid;=1&gsTable;=facility&gsSearchtype;=advanced

The Solar Energy Industries Association’s “Project Location Map” which can be found here:

https://www.seia.org/map/majorprojectsmap.php

also assisted in locating newer facilities along with the "Power Plants" shapefile, updated in December 16th, 2015, downloaded from the U.S. Energy Information Administration located here:

https://www.eia.gov/maps/layer_info-m.cfm

There were some facilities that were stumbled upon while searching for others, most of these are smaller scale sites located near farm infrastructure. Other sites were located by contacting counties that had solar developments within the county. Still, others

California has by far the greatest installed capacity of solar photovoltaic (PV) power of any U.S. state. As of March 2025, the Golden State had a cumulative solar power capacity of over ***** gigawatts. Texas followed with a capacity of roughly ***** gigawatts. Both U.S. states also had the largest solar PV capacity additions in 2024. Solar power across the U.S. Solar power accounts for around **** percent of the total electricity generated in the United States. Since the turn of the century, the solar PV capacity installed in the North American country has experienced exponential growth, surpassing *** gigawatts as of 2024, which is enough to power the equivalent of ** million average homes in the country. Even though the U.S. energy mix is still dominated by fossil fuels, renewable sources are forecast to grow in the upcoming years. Employment in the U.S. solar market The solar sector is an incubator for job growth across the United States. Over the last decade, employment figures in the U.S. solar market have increased nearly threefold. More than ******* people worked in the solar industry in 2023, with the state of California concentrating the largest solar workforce in the country.

This statistic represents the generation of solar power in California between 2006 and 2015. In 2015, **** million megawatt hours of electricity derived from solar sources were generated in the Western State.

In 2024, net solar power generation in the United States reached its highest point yet at 218.5 terawatt hours of solar thermal and photovoltaic (PV) power. Solar power generation has increased drastically over the past two decades, especially since 2011, when it hovered just below two terawatt hours. The U.S. solar industry In the United States, an exceptionally high number of solar-related jobs are based in California. With a boost from state legislation, California has long been a forerunner in solar technology. In the second quarter of 2024, it had a cumulative solar PV capacity of more than 48 gigawatts. Outside of California, Texas, Florida, and North Carolina were the states with the largest solar PV capacity. Clean energy in the U.S. In recent years, solar power generation has seen more rapid growth than wind power in the United States. However, among renewables used for electricity, wind has been a more common and substantial source for the past decade. Wind power surpassed conventional hydropower as the largest source of renewable electricity in 2019. While there are major environmental costs often associated with the construction and operation of large hydropower facilities, hydro remains a vital source of electricity generation for the United States.

Solar electrical generation data is reported for commercial power plants that
have a nameplate capacity of 1 MW or more. San Bernardino and Riverside
county had solar thermal in addition to solar photovoltaic electric generation.
Data originates from the California Energy Commission, and is classified using
the Jenk’s Natural Break’s method. Projection: NAD 1983 California (Teale)
Albers. Data is for 2024 and is current as of June 20, 2025. For more
information, contact John Hingtgen at john.hingtgen@energy.ca.gov.

Solar Resource Areas created were produced using a k-means method that groups solar generating plants into discrete regions based on their latitude, longitude, and distance to the coast. After facilities were grouped, the outermost facilities in each region were connected to create the boundaries for each region. To include all facilities inside each polygon, a 5 km buffer was used. Plants that are farther from a concentration of other plants are not included in a region and are instead displayed as outlying facilities. Areas outside California included in the the regions are a result of the mapping process and are not representing actual solar generating facilities. Based on the Quarterly Fuel and Energy Report dataset, this map focuses on data from plants of at least 1 MW capacity (commercial scale) and excludes smaller plants.

Description:

*This dataset provides detailed information about solar installations across California, focusing on their geographic and technical features. It includes rooftop and ground solar installations, in urban or rural settings. Each record specifies the area in acres, installation type, proximity to substations (categorized by voltage and regional coverage, such as CAISO), and suitability for solar energy projects. The data also features geometric properties, such as footprint(installation) area and perimeter, for spatial analysis.*

Key Features:

• Location information, including county and urban/rural classification.
• Proximity to high-voltage substations (≥100 kV and ≥200 kV) and CAISO substations.
• Solar installation type (e.g., rooftop, ground-mounted) and area in acres.
• Percentile rankings for distances to substations.
• Spatial details, including shape area and length for GIS applications.

Row 1 Columns:

County: Alameda County

Acres: 1.67

Install Type: Rooftop

Urban or Rural: Urban

Combined Class: Rooftop - Urban

Distance to Substation (GTET 100 Max Voltage): 0.16 miles

Substation Name (GTET 100 Max Voltage): Dixon Landing

Distance to CAISO Substation: 2.27 miles

Solar Technoeconomic Intersection: Within

Shape Area and Length: Area: 6768.95, Length: 365.80

Row 1_Summary:

A 1.67-acre rooftop solar project in urban Alameda County is just 0.16 miles from the Dixon Landing substation and 2.27 miles from the Los Esteros CAISO substation, with an area of 6,769 square units and a perimeter of 366 units.

Use Cases:

*The dataset supports energy planning, renewable energy development, and spatial analysis, providing insights into the distribution and characteristics of solar projects in California. It is particularly valuable for utility companies, policy analysts, and researchers focused on renewable energy infrastructure.*

Attribution:

Published by The California Energy Commission, by interpreting satellite imagery and combining multiple existing datasets from sources such as the UC Berkeley, and BLM Renewable Projects.

LICENSE: The data is available under the Creative Commons Attribution 4.0 International (CC BY 4.0).

NO ENDORSEMENT: The California Energy Commission does not endorse this work or its conclusions.

DISCLAIMER: Please independently verify the data and it's derivation(s) before applying it to research or decision-making.

This statistic represents California’s net summer capacity between for solar power 2006 and 2010. In 2010, the Western State had a net summer capacity for solar power of around *** megawatts.

A partnership with HSU and U.S. Department of Energy's National Renewable Energy Laboratory (NREL) to collect solar data to support future solar power generation in the United States. The measurement station monitors global horizontal, direct normal, and diffuse horizontal irradiance to define the amount of solar energy that hits this particular location.

Energy data is collected for power plants that have a nameplate capacity of 1 MW or more. Counties that are gray either did not report data or had no utility-scale (commercial) solar capacity. Map and data originate from the California Energy Commission Quarterly Fuel and Energy Reports. Data is classified using the Jenk’s Natural Break’s method. Data is from 2020 and is current as of December 13, 2021. Projection: NAD 1983 California (Teale) Albers. For more information, please contact Rebecca Vail at (916) 477-0738 or John Hingtgen at (916) 510-9747.

The map depicts Solar Generation Regions of California, which are regions with concentrations of operating commercial solar plants. The regions were delineated using a k-means method that groups the plants into discreet regions based on their latitude, longitude and distance to the coast. After facilities were grouped, the outermost facilities in each region were connected to create the boundaries for each region. To include all facilities inside each polygon, a 5 km cartographic buffer was used. Plants that are farther from a concentration of other plants are not included. Areas outside California included in the regions are the result of the mapping process and do not represent solar generation facilities. Based on the Quarterly Fuel and Energy Report dataset, this map focuses on plants of commercial scale (at least 1 MW capacity). For more information please contact John Hingtgen at john.hingtgen@energy.ca .gov. October 2022

This GIS dataset consists of polygons that represent the footprints of solar powered electric generation facilities and related infrastructure in California called Solar Footprints. The location of solar footprints was identified using other existing solar footprint datasets from various sources along with imagery interpretation. CEC staff reviewed footprints identified with imagery and digitized polygons to match the visual extent of each facility. Previous datasets of existing solar footprints used to locate solar facilities include: GIS Layers: (1) California Solar Footprints, (2) UC Berkeley Solar Points, (3) Kruitwagen et al. 2021, (4) BLM Renewable Project Facilities, (5) Quarterly Fuel and Energy Report (QFER)Imagery Datasets: Esri World Imagery, USGS National Agriculture Imagery Program (NAIP), 2020 SENTINEL 2 Satellite Imagery, 2023Solar facilities with large footprints such as parking lot solar, large rooftop solar, and ground solar were included in the solar footprint dataset. Small scale solar (approximately less than 0.5 acre) and residential footprints were not included. No other data was used in the production of these shapes. Definitions for the solar facilities identified via imagery are subjective and described as follows: Rooftop Solar: Solar arrays located on rooftops of large buildings. Parking lot Solar: Solar panels on parking lots roughly larger than 1 acre, or clusters of solar panels in adjacent parking lots. Ground Solar: Solar panels located on ground roughly larger than 1 acre, or large clusters of smaller scale footprints. Once all footprints identified by the above criteria were digitized for all California counties, the features were visually classified into ground, parking and rooftop categories. The features were also classified into rural and urban types using the 42 U.S. Code § 1490 definition for rural. In addition, the distance to the closest substation and the percentile category of this distance (e.g. 0-25th percentile, 25th-50th percentile) was also calculated. The coverage provided by this data set should not be assumed to be a complete accounting of solar footprints in California. Rather, this dataset represents an attempt to improve upon existing solar feature datasets and to update the inventory of "large" solar footprints via imagery, especially in recent years since previous datasets were published. This procedure produced a total solar project footprint of 150,250 acres. Attempts to classify these footprints and isolate the large utility-scale projects from the smaller rooftop solar projects identified in the data set is difficult. The data was gathered based on imagery, and project information that could link multiple adjacent solar footprints under one larger project is not known. However, partitioning all solar footprints that are at least partly outside of the techno-economic exclusions and greater than 7 acres yields a total footprint size of 133,493 acres. These can be approximated as utility-scale footprints. Metadata: (1) CBI Solar FootprintsAbstract: Conservation Biology Institute (CBI) created this dataset of solar footprints in California after it was found that no such dataset was publicly available at the time (Dec 2015-Jan 2016). This dataset is used to help identify where current ground based, mostly utility scale, solar facilities are being constructed and will be used in a larger landscape intactness model to help guide future development of renewable energy projects. The process of digitizing these footprints first began by utilizing an excel file from the California Energy Commission with lat/long coordinates of some of the older and bigger locations. After projecting those points and locating the facilities utilizing NAIP 2014 imagery, the developed area around each facility was digitized. While interpreting imagery, there were some instances where a fenced perimeter was clearly seen and was slightly larger than the actual footprint. For those cases the footprint followed the fenced perimeter since it limits wildlife movement through the area. In other instances, it was clear that the top soil had been scraped of any vegetation, even outside of the primary facility footprint. These footprints included the areas that were scraped within the fencing since, especially in desert systems, it has been near permanently altered. Other sources that guided the search for solar facilities included the Energy Justice Map, developed by the Energy Justice Network which can be found here:https://www.energyjustice.net/map/searchobject.php?gsMapsize=large&giCurrentpageiFacilityid;=1&gsTable;=facility&gsSearchtype;=advancedThe Solar Energy Industries Association’s “Project Location Map” which can be found here: https://www.seia.org/map/majorprojectsmap.phpalso assisted in locating newer facilities along with the "Power Plants" shapefile, updated in December 16th, 2015, downloaded from the U.S. Energy Information Administration located here:https://www.eia.gov/maps/layer_info-m.cfmThere were some facilities that were stumbled upon while searching for others, most of these are smaller scale sites located near farm infrastructure. Other sites were located by contacting counties that had solar developments within the county. Still, others were located by sleuthing around for proposals and company websites that had images of the completed facility. These helped to locate the most recently developed sites and these sites were digitized based on landmarks such as ditches, trees, roads and other permanent structures.Metadata: (2) UC Berkeley Solar PointsUC Berkeley report containing point location for energy facilities across the United States.2022_utility-scale_solar_data_update.xlsm (live.com)Metadata: (3) Kruitwagen et al. 2021Abstract: Photovoltaic (PV) solar energy generating capacity has grown by 41 per cent per year since 2009. Energy system projections that mitigate climate change and aid universal energy access show a nearly ten-fold increase in PV solar energy generating capacity by 2040. Geospatial data describing the energy system are required to manage generation intermittency, mitigate climate change risks, and identify trade-offs with biodiversity, conservation and land protection priorities caused by the land-use and land-cover change necessary for PV deployment. Currently available inventories of solar generating capacity cannot fully address these needs. Here we provide a global inventory of commercial-, industrial- and utility-scale PV installations (that is, PV generating stations in excess of 10 kilowatts nameplate capacity) by using a longitudinal corpus of remote sensing imagery, machine learning and a large cloud computation infrastructure. We locate and verify 68,661 facilities, an increase of 432 per cent (in number of facilities) on previously available asset-level data. With the help of a hand-labelled test set, we estimate global installed generating capacity to be 423 gigawatts (−75/+77 gigawatts) at the end of 2018. Enrichment of our dataset with estimates of facility installation date, historic land-cover classification and proximity to vulnerable areas allows us to show that most of the PV solar energy facilities are sited on cropland, followed by arid lands and grassland. Our inventory could aid PV delivery aligned with the Sustainable Development GoalsEnergy Resource Land Use Planning - Kruitwagen_etal_Nature.pdf - All Documents (sharepoint.com)Metadata: (4) BLM Renewable ProjectTo identify renewable energy approved and pending lease areas on BLM administered lands. To provide information about solar and wind energy applications and completed projects within the State of California for analysis and display internally and externally. This feature class denotes "verified" renewable energy projects at the California State BLM Office, displayed in GIS. The term "Verified" refers to the GIS data being constructed at the California State Office, using the actual application/maps with legal descriptions obtained from the renewable energy company. https://www.blm.gov/wo/st/en/prog/energy/renewable_energy

In 2022, California was the state with the largest number of newly installed residential solar systems in the United States. The Golden State installed more than 258,000 home solar systems that year. California was also the state with the largest cumulative number of residential systems installed. The total number of residential solar installations has increased significantly in the last years across the United States.

Energy data is collected for power plants that have a nameplate capacity of 1 MW or more. Counties that are gray had no utility-scale solar capacity. Data originates from the California Energy Commission, and is classified using the Jenk’s Natural Break’s method. Projection: NAD 1983 California (Teale) Albers. Data is for 2022 and is current as of August 7, 2023. For more information, contact Gordon Huang at gordon.huang@energy.ca.gov or John Hingtgen at john.hingtgen@energy.ca.gov.

This map of California depicts the amount of solar energy produced in each county (gigawatt hours) as well as the capacity (MW) of each county's utility-scale resources. This data is for 2018 and statewide totals are indicated.

Map of 2019 Utility-Scale Solar Capacity by CountyThis map of California depicts the amount of utility scale solar generation capacity in each county (MW). This data is for 2019 and statewide totals are indicated.

As of 2024, roughly **** percent of single-unit housing in the United States was equipped with solar panels. The market penetration of residential solar is projected to increase in the next years, reaching some ** percent by 2032. This translates to roughly **** million U.S. homes powered by solar in that year. The landscape of residential solar in the U.S. In 2023, the residential solar PV capacity in the U.S. grew to more than ** gigawatts, which represents roughly ** percent of the total solar installations in the country. California, Arizona, and Texas are the states with the highest number of residential solar systems. As of the end of 2022, California had roughly *** million homes with a solar PV system installed. The state is the leading solar market in the United States. U.S. commercial solar systems The commercial solar market, comprised of on-site installations for businesses, governments, and non-profits, has also grown significantly in the last years. In 2023, the installed solar PV commercial capacity reached almost ** gigawatts in the United States. The cost of commercial solar systems in the U.S. is roughly half of that of residential solar, amounting to some **** U.S. dollars per watt installed.

Solar energy accounted for some 6.91 percent of electricity generation in the United States in 2024, up from a 5.62 percent share a year earlier. California was the state with the largest percentage of its electricity generation covered by solar, with approximately 28.2 percent.

Comprehensive dataset containing 1,425 verified Solar energy equipment supplier businesses in California, United States with complete contact information, ratings, reviews, and location data.

Comprehensive dataset containing 1,536 verified Solar energy company businesses in California, United States with complete contact information, ratings, reviews, and location data.