The geothermal energy industry in California comprises a number of diverse companies specializing in a variety of methodologies, technologies and services. From harnessing the power of concentrated sunlight to optimizing power generation through advanced engineering, these businesses are leading the charge towards sustainable future. They provide renewable and environmentally-friendly energy solutions leveraging the earth's natural heat. Starting from industrial processes such as production of cement or steel, to offering competitively-priced, baseload renewable energy, the industry paints an optimistic picture of an emission-less tomorrow.


Top 25 geothermal energy companies in California

1. Heliogen

  • Website: heliogen.com
  • Headquarters: Pasadena, California, United States
  • Founded: 2013
  • Headcount: 51-200
  • Latest funding type: Post Ipo Equity
  • LinkedIn

Heliogen is a renewable energy technology company utilizing concentrated sunlight and thermal storage to decarbonize industry. They provide industrial-grade heat capable of replacing fossil fuels in industrial processes including the production of cement, steel, and petrochemicals.


2. Thermochem, Inc.

  • Website: thermochem.com
  • Headquarters: Santa Rosa, California, United States
  • Founded: 1985
  • Headcount: 11-50
  • LinkedIn

Thermochem is a global leader in testing, engineering, and consulting services for the renewable geothermal power sector. With over 30 years of experience, we provide specialized services and instrumentation to optimize energy extraction and power generation. We are committed to protecting our clients' long-term assets and increasing the efficiency of their operations.


3. Geothermic Solution Inc.

Geothermic Solution offers patented deep rock, high temperature GeoHeatâ„¢ Harvesting Technology for competitively priced, baseload, renewable energy.


4. Access Energy

  • Website: access-energy.com
  • Headquarters: Cerritos, California, United States
  • Headcount: 11-50

Access Energy produces reliable clean electricity by using the latest technology of Organic Rankine Cycle (ORC) and Integrated Power Module. The fully automated systems require no fuel or oil lubrication and utilize environmentally friendly, non-combustible and non-flammable working fluid.


5. CleanTechnica

CleanTechnica is a website that provides news and analysis on clean energy technologies and sustainable solutions.


6. Solar Living Institute

Solarliving.org is an online platform that offers professional solar training courses and resources for solar PV, storage, finance, marketing, and green building. They provide a wide range of online courses covering various topics related to solar energy, including solar thermal, geothermal, biomass, and more. The website also offers information on eco-building techniques and sustainable solar living.


7. Global Energy Network Institute (GENI)

  • Website: geni.org
  • Headquarters: San Diego, California, United States
  • Founded: 1986
  • Headcount: 11-50
  • LinkedIn

The Global Energy Network Institute (GENI) focuses on the interconnection of electric power networks between communities, nations and continents, with an emphasis on tapping abundant renewable energy resources. This strategy is the highest priority of the World Game simulation developed by Buckminster Fuller. Linking renewable energy between all nations mollifies conflicts, grows economies, and increases the quality of life and health for all.


8. CleanTech Energy, Inc.

CleanTech Energy is a company that offers sustainable energy solutions with a focus on RNG, hydrogen, and natural gas project finance, infrastructure M&A, and asset management. They also specialize in solar, wind and energy storage, offering project development and technology advisory services.


9. SimpliPhi Power, Inc.

SimpliPhi Power is a component supplier that offers energy storage systems for residential, commercial, and industrial applications. Their batteries are scalable, require minimal maintenance, and have a proven track record in various climates and use-cases globally.


10. Collins Jack

EVNewsReport is a source of news for electric vehicle-related articles, including renewable energy and energy storage. The website offers industry insight and technical information for renewable energy enthusiasts.


11. Revco Solar Engineering Inc

  • Website: revcosolar.com
  • Headquarters: Laguna Hills, California, United States
  • Founded: 1976
  • Headcount: 11-50
  • LinkedIn

Revco Solar is a leader in residential and commercial solar installations and services in Orange County and Southern California. They offer thermal solar services, pool solar, and solar electric systems. With over 40 years of experience, they have a strong reputation for providing high-quality solar solutions.


12. Salas O'Brien

  • Website: salasobrien.com
  • Headquarters: Santa Ana, California, United States
  • Founded: 1975
  • Headcount: 1001-5000
  • LinkedIn

Salas O'Brien is a design services company that offers a range of consulting and engineering services to clients in various industries. They specialize in helping clients navigate the complex process of designing and implementing renewable energy systems, including geothermal and renewables. With a focus on sustainability, Salas O'Brien provides solutions for complex challenges and has a passion for technical mastery in their craft.


13. Permacity Construction Corp

  • Website: permacity.com
  • Headquarters: Los Angeles, California, United States
  • Founded: 2003
  • Headcount: 11-50
  • Latest funding type: Acquired
  • LinkedIn

PermaCity is the largest commercial solar developer and installer in Los Angeles, providing project funding and converting unused roof assets into revenue while contributing to a sustainable climate. They offer solar electricity, zero energy buildings, and solar hot water services.


14. Liquid Bread Gastropub

The company is a sustainable energy technology firm, working towards generating energy from waste. They specialize in converting biomass waste into clean energy solutions, thereby contributing towards a cleaner and greener environment.


15. Earth Systems

Earth Systems is a geoprofessional services company that provides geotechnical engineering, geology, hydrogeology, and environmental construction materials testing and inspection services. They specialize in water and wastewater treatment, renewable energy, green building and sustainability, public works, military, commercial and industrial projects.


16. Seismic Brewing Company

Seismic Brewing Co. is a sustainable craft beer brewery located in Sonoma County, California. They are committed to brewing flavorful, outstanding craft beers while prioritizing water conservation and renewable energy. Their mission is to rewrite the books on sustainable brewing and be good stewards of their resources and community.


17. Power Efficiency Corporation

Power Efficiency is a company focused on promoting and implementing energy-efficient solutions for homes and businesses. They offer a range of products and services aimed at reducing energy consumption and helping customers save money while minimizing their environmental impact. With a strong emphasis on sustainability and green technology, Power Efficiency strives to be a leading player in the energy efficiency industry.


18. Carbon Collective

  • Website: carboncollective.co
  • Headquarters: Albany, California, United States
  • Founded: 2020
  • Headcount: 1-10
  • Latest funding type: Seed
  • LinkedIn

Carbon Collective is an SEC-registered investment adviser specializing in sustainable investing. They offer advisory services to assist clients in achieving discrete financial goals.


19. Edison International

  • Website: edison.com
  • Headquarters: Rosemead, California, United States
  • Founded: 1886
  • Headcount: 10001+
  • Latest funding type: Ipo
  • LinkedIn

Edison.com is a company focused on providing clean energy solutions and services. They offer various products and services related to electric transportation, grid modernization, cybersecurity, and energy storage. With a commitment to sustainability, they aim to contribute to the emerging clean energy economy.


20. Global Energy Monitor

Global Energy Monitor (GEM) is a data-driven organization that provides information and analysis on energy projects and industries worldwide. It offers trackers for coal plants, coal mines, coal terminals, solar power, wind power, hydropower, geothermal power, bioenergy power, nuclear power, oil and gas extraction, oil infrastructure, and gas infrastructure. GEM's data enables informed decision-making and supports global efforts towards a transition to clean and sustainable energy sources.


21. Legence

  • Website: wearelegence.com
  • Headquarters: San Jose, California, United States
  • Founded: 1963
  • Headcount: 1001-5000
  • Latest funding type: Acquired
  • LinkedIn

Legence is a leading company in the clean energy finance industry, providing sustainable and high-performance solutions for built environments. With over 40 years of experience, Legence offers services such as retro-commissioning, energy efficiency, solar photovoltaics, and energy as a service. They aim to improve the performance and sustainability of spaces we occupy.


22. Windmill Capital Management

Windmill Capital Management helps high net worth, institutional and corporate investors make direct investments in cash-flow assets, including alternative /renewable energy and real estate. We bring more than a quarter century of experience working with investors and sponsors to create outstanding outcomes.


23. Green NRG Institute

Focus on business applications in energy.


24. Energy Savers 2

Energy Savers 2 is a utility service provider offering comprehensive services to clients in the energy and utility industry. With over 20 years of experience, Energy Savers 2 specializes in energy audits, telecom audits, energy efficiency review and implementation, renewable energy, lighting retrofit, solar and wind energy, and more.


25. Clean Energy

  • Website: cleanenergyfuels.com
  • Headquarters: Newport Beach, California, United States
  • Founded: 1997
  • Headcount: 1001-5000
  • Latest funding type: Post Ipo Debt
  • LinkedIn

Clean Energy Fuels is a company that produces and sells renewable natural gas, a clean alternative fuel. They help reduce greenhouse gas emissions and provide sustainable energy solutions for various industries.


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