California is a state at the forefront of solar energy, propelling the transition to clean power through diverse companies specializing in innovative solutions. These firms range from large enterprises like SunPower, pioneering efficient solar technology, to smaller firms focusing on residential installations, offering products such as solar panels, battery storage, and inverter systems. The industry is rapidly evolving with advancements in technology and supportive policies, making solar energy not only more accessible but also cost-effective. Experts predict that California's solar market will continue to grow, significantly contributing to the state's ambitious sustainability goals while impacting global energy dynamics.

This list highlights 23 significant solar energy companies based in California, featuring firms of varying sizes from established leaders like SunPower, founded in 1985, to newer entrants such as GAF Energy, established in 2019. Companies operate across multiple locales, including El Cajon and San Francisco, specializing in products like residential solar panels and energy storage solutions. Each company shows a unique capacity for innovation, customer focus, and operational success. The commitment of these firms to renewable energy solutions places them at the heart of California’s evolving energy landscape.

Continue reading to discover the top solar energy companies in California.

Top 23 Solar Energy Companies in California

1. SunPower Corporation

• Website: us.sunpower.com
• Ownership type: Private Equity
• Headquarters: Richmond, California, United States (USA)
• Employee distribution: United States (USA) 55%, Philippines 35%, Mexico 4%, Other 7%
• Latest funding: Other (Debt), $300.0M, February 2024
• Founded year: 1985
• Headcount: 1001-5000
• LinkedIn: sunpower-corporation

SunPower Corporation, based in Richmond, California, is a prominent player in the solar energy sector, primarily focusing on residential solar solutions. Established in 1985, the company has built a reputation for providing high-quality solar panels, battery storage systems, and electric vehicle (EV) charging solutions. SunPower aims to help homeowners reduce their energy costs and environmental impact through innovative solar technology. The company operates through a network of certified dealers, ensuring personalized service and support for its customers. With a workforce of approximately 3,572 employees, SunPower has a significant presence in the United States, the Philippines, and Mexico. In February 2024, the company secured $300 million in funding, reflecting its ongoing efforts to enhance its product offerings and market reach. SunPower's commitment to quality is underscored by its industry-leading 25-year warranty on solar panels, which speaks to the durability and reliability of its products. The company continues to adapt to market demands, including the growing trend towards energy independence and sustainability.

2. Semper Solaris

• Website: sempersolaris.com
• Ownership type: Private
• Headquarters: El Cajon, California, United States (USA)
• Employee distribution: United States (USA) 99%
• Founded year: 2012
• Headcount: 501-1000
• LinkedIn: semper-solaris

Semper Solaris, based in El Cajon, California, is a private company specializing in solar energy solutions, roofing services, battery storage, and HVAC systems. Founded in 2012, the company primarily serves homeowners looking to improve energy efficiency and lower utility costs. Semper Solaris has carved out a niche in the residential solar market, emphasizing quality service and customer satisfaction. They offer a range of products, including solar panels from reputable manufacturers like Silfab and Qcells, and battery storage solutions from Tesla and Enphase. The company also provides comprehensive roofing services, ensuring that installations are durable and energy-efficient. Their commitment to community is reflected in initiatives like Semper Cares, which supports veterans and their families. Semper Solaris has received numerous awards for its performance in solar installations, underscoring its operational success and industry recognition.

3. d.light

• Website: dlight.com
• Ownership type: Venture Capital
• Headquarters: San Francisco, California, United States (USA)
• Employee distribution: Kenya 48%, Tanzania 13%, India 13%, Other 25%
• Latest funding: Other (Debt), $176.0M, July 2024
• Founded year: 2007
• Headcount: 501-1000
• LinkedIn: d-light-design

d.light, founded in 2007 and based in San Francisco, California, is a solar energy company dedicated to enhancing energy access for underserved communities. The company specializes in solar home systems, inverters, and appliances, all designed to improve the quality of life for consumers. With a workforce of nearly 1,000 employees, d.light operates primarily in regions like Kenya, Tanzania, India, Nigeria, and Uganda, where it has established a significant presence. The company has successfully empowered over 180 million individuals by providing affordable solar solutions through its innovative Pay-As-You-Go financing model. This approach not only makes solar energy accessible but also supports economic growth in these communities. d.light has also engaged in impactful carbon projects, offsetting 40 million tons of CO2, further demonstrating its commitment to sustainability. Recently, the company secured $176 million in funding, underscoring its active role in the solar energy sector and its potential for future growth.

4. Renogy

• Website: renogy.com
• Ownership type: Venture Capital
• Headquarters: Ontario, California, United States (USA)
• Employee distribution: United States (USA) 48%, China 48%, Czech Republic 2%, Other 2%
• Latest funding: Series E-K, June 2022
• Founded year: 2010
• Headcount: 501-1000
• LinkedIn: renogy

Renogy, based in Ontario, California, is a solar energy provider that specializes in renewable energy solutions. Founded in 2010, the company has carved out a niche in the solar market by offering a comprehensive range of products, including solar panels, batteries, and inverters. Renogy primarily serves both consumers and businesses, aiming to help them achieve energy independence and cost savings through solar power. The company operates mainly through an online platform, which allows for easy access and purchasing of solar energy systems. With a workforce distributed across the United States and China, Renogy has a global reach. Their recent funding round in June 2022 indicates ongoing investor confidence in their business model and growth potential. Renogy's mission is to accelerate the adoption of clean energy solutions, making them a relevant player in the solar energy industry.

5. Freedom Forever

• Website: freedomforever.com
• Ownership type: Private
• Headquarters: Temecula, California, United States (USA)
• Employee distribution: United States (USA) 99%, Other 1%
• Founded year: 2011
• Headcount: 1001-5000
• LinkedIn: freedom-forever

Freedom Forever, based in Temecula, California, is a private solar energy provider that specializes in residential solar panel installation and energy storage solutions. Founded in 2011, the company aims to help homeowners reduce their energy costs and achieve greater energy independence through renewable energy. Freedom Forever offers tailored solar systems and flexible financing options, ensuring a smooth transition to solar power for its customers. The company prides itself on its customer service, evidenced by its unique 25-year production guarantee, which assures clients of the energy output from their solar systems. With a workforce of approximately 1,800 employees, Freedom Forever has made significant strides in the solar industry, actively installing systems across multiple states in the U.S. Their innovative tools, such as the Volt mobile app for sales management, further enhance their operational efficiency and customer engagement.

6. Greentech Renewables

• Website: greentechrenewables.com
• Ownership type: Private
• Headquarters: San Diego, California, United States (USA)
• Employee distribution: United States (USA) 100%
• Founded year: 1957
• Headcount: 1001-5000
• LinkedIn: cedgreentech

Greentech Renewables, established in 1957 and headquartered in San Diego, California, specializes in renewable energy solutions with a strong emphasis on solar energy. The company provides a wide array of products, including solar panels, inverters, energy storage systems, and solar racking. They also offer design services and financing solutions tailored for residential, commercial, and organizational clients. Greentech Renewables aims to support customers in implementing solar technology efficiently and cost-effectively. Their operations extend beyond mere product supply; they actively engage in project design and management, ensuring that clients receive comprehensive support throughout the solar installation process. With a workforce of over 600 employees, the company is well-equipped to handle various projects and customer needs, reinforcing its position in the renewable energy sector.

7. Green Solar Technologies

• Website: greensolartechnologies.com
• Ownership type: Corporate
• Headquarters: Los Angeles, California, United States (USA)
• Employee distribution: United States (USA) 100%
• Latest funding: February 2024
• Founded year: 2010
• Headcount: 201-500
• LinkedIn: green-solar-technologies

Green Solar Technologies, based in Los Angeles, California, is a solar energy provider that specializes in delivering affordable solar solutions to residential and commercial clients. Established in 2010, the company has built a reputation for its commitment to high-quality, American-made solar products. They offer a comprehensive suite of services, including solar panel installation, energy storage systems, and customized financing options designed to help customers reduce their energy costs and carbon footprint. With a focus on making solar energy accessible, Green Solar Technologies has positioned itself as a knowledgeable partner in the solar industry, leveraging over a decade of experience to guide clients through the transition to renewable energy. Their dedication to customer satisfaction and innovative solutions reflects their role as a proactive participant in the solar energy market.

8. GAF Energy

• Website: gaf.energy
• Ownership type: Private
• Headquarters: San Jose, California, United States (USA)
• Employee distribution: United States (USA) 100%
• Latest funding: Other (Grant), $1.6M, May 2024
• Founded year: 2019
• Headcount: 201-500
• LinkedIn: gaf-energy

GAF Energy, founded in 2019 and based in San Jose, California, is a private company specializing in solar roofing solutions. The company is known for its Timberline Solar™ product, which integrates solar technology directly into roofing materials, allowing homeowners to benefit from energy-efficient roofs that also generate clean electricity. GAF Energy primarily serves homeowners looking for sustainable energy options and roofing contractors seeking advanced products to enhance their service offerings. With a workforce of approximately 383 employees, the company is actively involved in the U.S. market, emphasizing local job creation through its manufacturing and installation processes. GAF Energy has also received a grant of $1.6 million in May 2024, indicating its commitment to innovation and growth in the solar energy sector.

9. Xero Solar

• Website: xerosolar.com
• Ownership type: Private
• Headquarters: El Segundo, California, United States (USA)
• Employee distribution: United States (USA) 100%
• Founded year: 2010
• Headcount: 51-200
• LinkedIn: xerosolar

Xero Solar is a private solar energy company located in El Segundo, California, established in 2010. The firm specializes in designing, installing, and managing solar energy systems tailored for both residential and commercial customers. With a dedicated team of around 37 employees, Xero Solar emphasizes a consultative approach to projects, ensuring that each installation meets the unique needs of its clients. They also provide energy storage solutions, enhancing the efficiency and reliability of solar energy systems. The company prides itself on using high-quality products and maintaining a strong focus on customer satisfaction and sustainability. Xero Solar has installed numerous systems across Southern California, contributing to the region's renewable energy goals and promoting a cleaner environment.

10. Baker Home Energy

• Website: bakerhomeenergy.com
• Ownership type: Family Owned
• Headquarters: Escondido, California, United States (USA)
• Employee distribution: United States (USA) 96%, Mexico 4%
• Founded year: 2007
• Headcount: 201-500
• LinkedIn: bakerhomeenergy

Baker Home Energy, based in Escondido, California, is a family-owned company that specializes in renewable energy solutions. Founded in 2007, the firm has built a reputation for providing solar energy systems, home battery installations, and comprehensive home services, including heating, cooling, and roofing solutions. With a workforce of approximately 162 employees, Baker Home Energy focuses on helping homeowners in Southern California manage their energy consumption effectively. The company emphasizes reducing energy costs and enhancing home comfort through efficient energy management. Their services are designed to empower customers to generate and store their own energy, thereby promoting sustainability and resilience against rising energy prices. Baker Home Energy also positions itself as a trusted partner for homeowners, offering guidance and support throughout the energy management process.

11. Alta Devices

• Website: altadevices.com
• Ownership type: Corporate
• Headquarters: Sunnyvale, California, United States (USA)
• Employee distribution: United States (USA) 100%
• Latest funding: December 2013
• Founded year: 2008
• Headcount: 201-500
• LinkedIn: alta-devices

Alta Devices, founded in 2008 and based in Sunnyvale, California, is a company dedicated to advancing solar energy technology. They specialize in the development of high-efficiency solar panels, batteries, and inverters, catering to both homeowners and businesses. With a team that boasts over 20 years of combined experience in the solar industry, Alta Devices focuses on educating consumers about the benefits and practicalities of solar energy. Their innovative approach has led to the creation of solar cells that have set world records for efficiency, particularly using Gallium Arsenide technology. The company aims to empower users by providing solutions that not only reduce energy costs but also contribute to a more sustainable future. Their website serves as a resource hub, offering insights into solar fundamentals, product comparisons, and information on tax credits and incentives for solar adoption.

12. Renova Energy

• Website: renovaenergy.com
• Ownership type: Private
• Headquarters: Palm Desert, California, United States (USA)
• Latest funding: September 2022
• Founded year: 2006
• Headcount: 201-500
• LinkedIn: renova-solar

Renova Energy, based in Palm Desert, California, is a private solar energy provider that has been operational since 2006. The company specializes in the installation, maintenance, and cleaning of solar panels, serving both residential and commercial customers primarily in California and Arizona. With a workforce of approximately 102 employees, Renova Energy has built a reputation for delivering quality service and innovative solutions. They are recognized for their customer-centric approach, with over half of their new business stemming from referrals. The company has received several accolades, including multiple awards from SunPower for excellence in customer service and installation. Renova Energy also emphasizes community involvement and education, further enhancing their standing in the solar energy sector.

13. REC Solar

• Website: recsolar.com
• Ownership type: Private Equity
• Headquarters: San Luis Obispo, California, United States (USA)
• Employee distribution: United States (USA) 53%, Singapore 35%, Norway 9%, Other 3%
• Latest funding: October 2023
• Founded year: 1997
• Headcount: 11-50
• LinkedIn: rec-solar

REC Solar, founded in 1997 and based in San Luis Obispo, California, is a commercial solar energy provider that specializes in onsite solar, energy storage, and community solar solutions. The company serves a variety of clients, including businesses, municipalities, and educational institutions, helping them to lower energy costs and meet sustainability objectives through renewable energy projects. With a workforce of approximately 436 employees, REC Solar has completed over 700 projects nationwide, totaling 675 MW of solar and storage capacity. Their services include expert design, financing options, and ongoing maintenance, ensuring that clients receive comprehensive support throughout the lifecycle of their solar installations. REC Solar's commitment to integrity and high-quality standards is evident in their approach to project management and customer relations, making them a trusted partner in the commercial solar sector.

14. Pattern Energy

• Website: patternenergy.com
• Ownership type: Corporate
• Headquarters: San Francisco, California, United States (USA)
• Employee distribution: United States (USA) 92%, Canada 7%
• Latest funding: December 2024
• Founded year: 2012
• Headcount: 501-1000
• LinkedIn: pattern-energy

Pattern Energy Group LP, founded in 2012 and based in San Francisco, California, is a corporate entity focused on renewable energy. The company develops, constructs, owns, and operates utility-scale wind and solar power facilities across North America. With a global development portfolio of approximately 29 gigawatts and around 6 gigawatts of installed capacity, Pattern Energy is committed to providing sustainable energy solutions. They have completed over 750 commercial solar projects through their affiliate, Solect Energy, and are actively involved in energy storage and transmission projects. The company emphasizes community engagement and environmental stewardship, aiming to build trust and transparency with the communities they serve. Their operational footprint includes significant investments in local economies, with a focus on creating jobs and supporting sustainable practices.

15. Infinity Solar

• Website: infinitysolar.net
• Ownership type: Private
• Headquarters: Orange, California, United States (USA)
• Employee distribution: United States (USA) 100%
• Founded year: 1999
• Headcount: 11-50
• LinkedIn: infinity-solar-orange-ca

Infinity Solar, based in Orange, California, has been a player in the solar energy industry since its inception in 1999. The company specializes in custom-designed solar panel and home battery systems, serving both residential and commercial customers. Their product offerings include well-known brands such as Tesla Powerwall and Panasonic solar panels, which are integral to their strategy of reducing electricity costs and promoting sustainable energy solutions. Infinity Solar prides itself on delivering high-quality installation services, ensuring that each system is tailored to meet the specific energy needs of its clients. They also provide various financing options, making the transition to renewable energy more accessible. With a dedicated team of certified installers and a focus on customer satisfaction, Infinity Solar aims to facilitate the adoption of solar energy in Southern California, contributing to the broader goal of sustainability in the energy sector.

16. 8minute Solar Energy

• Website: 8minute.com
• Ownership type: Private
• Headquarters: Los Angeles, California, United States (USA)
• Founded year: 2009
• Headcount: 51-200
• LinkedIn: 8minute

8minute Solar Energy, now operating under the name Avantus, is a private clean energy company based in Los Angeles, California. Founded in 2009, Avantus specializes in renewable energy solutions, particularly solar power and energy storage. The company serves utilities and organizations by providing innovative energy products and services tailored to meet a variety of energy needs. Avantus has developed a significant project pipeline, with a focus on delivering reliable and affordable clean energy while actively addressing climate change. Their portfolio includes some of the largest solar and energy storage facilities in the United States, demonstrating their capability in executing large-scale projects. Avantus is committed to advancing clean energy technology and has a strong emphasis on research and development, which allows them to optimize performance and reduce costs. Their recent acquisition by KKR highlights their growth potential and strategic importance in the renewable energy sector.

17. Stellar Solar

• Website: stellarsolar.net
• Ownership type: Private
• Headquarters: Oceanside, California, United States (USA)
• Employee distribution: United States (USA) 100%
• Founded year: 1998
• Headcount: 51-200
• LinkedIn: stellar-solar-inc-

Stellar Solar, based in Oceanside, California, is a private solar energy company that has been operational since 1998. With a workforce of approximately 82 employees, the company specializes in solar panel installations, battery storage solutions, and electric vehicle (EV) charging systems for both residential and commercial clients. Over the years, Stellar Solar has completed more than 15,000 installations, showcasing its extensive experience in the field. The company has been recognized multiple times as the best solar company in San Diego, reflecting its strong local presence and customer satisfaction. Stellar Solar also emphasizes energy independence for its customers, helping them reduce energy costs through renewable energy solutions. Their partnership with Tesla as a certified installer of the Powerwall 3 further highlights their commitment to innovative energy storage solutions. Stellar Solar operates primarily in Southern California and has expanded its services to Michigan, demonstrating its growth and adaptability in the solar market.

18. Green Home Systems

• Website: greenhomesystems.com
• Ownership type: Private
• Headquarters: Los Angeles, California, United States (USA)
• Employee distribution: United States (USA) 100%
• Founded year: 2010
• Headcount: 51-200
• LinkedIn: greenhomesystemsus

Green Home Systems, based in Los Angeles, California, is a private solar energy provider that has been operational since 2010. The company focuses on solar panel installations and energy solutions tailored for residential customers. They offer a range of products, including solar panels, inverters, and batteries, sourced from well-known manufacturers such as Panasonic and Enphase. Green Home Systems prides itself on its customer service, managing the entire installation process from initial consultation to final setup. With a presence in 21 states and a network of over 1,000 installers, the company has successfully served more than 11,000 customers. Their mission emphasizes providing affordable and efficient clean energy solutions, contributing to sustainability while helping homeowners save on energy costs.

19. Mosaic (joinmosaic.com)

• Website: joinmosaic.com
• Ownership type: Private Equity
• Headquarters: Oakland, California, United States (USA)
• Employee distribution: United States (USA) 98%, Jamaica 2%
• Latest funding: $40.0M, August 2016
• Founded year: 2011
• Headcount: 201-500
• LinkedIn: joinmosaic

Mosaic, founded in 2011 and based in Oakland, California, operates as a clean energy financing company. It specializes in offering flexible financing options tailored for residential solar projects. By collaborating with contractors, Mosaic simplifies the process for homeowners looking to adopt solar energy solutions. The company aims to reduce energy costs for homeowners while enhancing property values through sustainable upgrades. Mosaic's services extend beyond solar financing to include options for battery storage, EV charging, and other home improvements. With a workforce of approximately 195 employees, the company has raised significant funding, amounting to $40 million as of August 2016, which supports its operations and growth in the clean energy sector. Mosaic's commitment to facilitating the transition to clean energy underscores its relevance in the solar industry.

20. Sunlux

• Website: sunlux.com
• Ownership type: Private
• Headquarters: Placentia, California, United States (USA)
• Employee distribution: United States (USA) 100%
• Founded year: 2014
• Headcount: 51-200
• LinkedIn: sunlux-energy-inc

Sunlux, based in Placentia, California, is a private solar installation company that has been operational since 2014. The firm specializes in providing renewable energy solutions tailored for both residential and commercial clients. Their service portfolio includes solar panel installation, battery storage systems, and roofing services, which allows them to address a range of energy needs. Sunlux is dedicated to helping customers lower their energy expenses while minimizing their environmental footprint. With a team of certified installers and a focus on customer satisfaction, Sunlux has completed over 7,000 solar installations, translating to significant energy savings for their clients. The company operates primarily in Southern California and Central Texas, reinforcing its commitment to the solar energy market.

21. SolarCraft

• Website: solarcraft.com
• Ownership type: Family Owned
• Headquarters: Novato, California, United States (USA)
• Employee distribution: United States (USA) 100%
• Founded year: 1984
• Headcount: 11-50
• LinkedIn: solarcraft

SolarCraft, based in Novato, California, has been a player in the solar energy industry since 1984. The company specializes in solar electric systems and battery backup solutions, catering to both residential and commercial clients. With a focus on helping customers reduce electricity costs and achieve energy independence, SolarCraft has completed over 9,000 installations in the North Bay area. They are recognized for their expertise, holding licenses as both a General Contractor and an Electrical Contractor. SolarCraft is also notable for being 100% employee-owned, which fosters a strong commitment to quality service and community support. Their extensive experience and dedication to sustainable energy solutions position them as a significant contributor to the solar energy market.

22. Clean Solar

• Website: cleansolar.com
• Ownership type: Private
• Headquarters: San Jose, California, United States (USA)
• Employee distribution: United States (USA) 100%
• Founded year: 2007
• Headcount: 11-50
• LinkedIn: clean-solar

Clean Solar, based in San Jose, California, is a private company specializing in residential solar panel installation and battery storage solutions. Founded in 2007, the company has carved out a niche in helping homeowners achieve energy independence while reducing their electricity costs through renewable energy. Clean Solar provides a comprehensive suite of services, including solar monitoring, maintenance, and the installation of electric vehicle charging stations. The firm is recognized for its commitment to quality and customer satisfaction, as evidenced by numerous positive client testimonials. Clean Solar also emphasizes its role in the evolving solar market, particularly in California, where solar technology is mandated for new homes. Their innovative approach includes a 15-year production guarantee, which ensures that clients receive the energy output promised at the time of installation. This focus on reliability and customer service positions Clean Solar as a significant player in the residential solar sector.

23. Sustainable Energy Group - SEG

• Website: sustainableenergygroup.com
• Ownership type: Private
• Headquarters: Grass Valley, California, United States (USA)
• Employee distribution: United States (USA) 100%
• Founded year: 2004
• Headcount: 11-50
• LinkedIn: segenergy

Sustainable Energy Group - SEG, based in Grass Valley, California, is a solar energy company that has been operational since 2004. The firm specializes in the installation of solar energy systems and backup power solutions, catering to residential, commercial, and non-profit clients. SEG is dedicated to helping its customers achieve energy independence while reducing their energy costs through renewable energy solutions. The company prides itself on its local expertise, having served various communities in Northern California, including Grass Valley, Nevada City, and surrounding areas. SEG is a licensed contractor in multiple disciplines, including general, electrical, solar, and plumbing, which allows them to offer comprehensive services. Their commitment to quality is reflected in their 25-year parts and labor warranty, and they emphasize clear communication and customer satisfaction throughout the installation process.

Solar Energy Insights: Key Companies in California

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