ThermaSource Raises $41.5 Million

ThermaSource, a Santa Rosa, Calif.-based provider of drilling, engineering and consulting services to the geothermal energy sector, has raised $41.5 million in new private equity funding. Rustic Canyon Partners was joined by return backers Riverstone Holdings and US Renewables Group. ThermaSource has now raised $93 million in private equity and debt.




ThermaSource LLC, one of the fastest growing providers of drilling, engineering and consulting services to the renewable geothermal energy sector, is pleased to report the completion of a new round of private equity financing, raising $41.5 million from Riverstone Holdings LLC, US Renewables Group, and Rustic Canyon Partners.


ThermaSource is using these resources to finance the acquisition of geothermal drilling rigs and to develop the associated drilling services including engineering, mud-logging, cementing and exploration. The initial equity investment in February of 2007 by Riverstone and US Renewables Group was $20 million. To date, ThermaSource has raised $93 million of equity and debt over the past two years. The company expects to double employment, from 210 currently to more than 420 by the end of the year, as it expands operations domestically and internationally.


“This equity investment represents a solid endorsement of our business strategy, which indicates we are delivering on our business plan and have established a platform for long term, sustained growth,” said Louis E. Capuano, Jr., president and CEO of ThermaSource LLC. For more information about ThermaSource, visit


About Riverstone Holdings LLC

Riverstone Holdings LLC and The Carlyle Group jointly sponsor the Riverstone/Carlyle energy funds. Riverstone, a New York-based energy and power-focused private equity firm founded in 2000, has approximately $13.7 billion under management. Riverstone conducts buyout and growth capital investments in the midstream, upstream, power, oilfield service, and renewable sectors of the energy industry. To date, the firm has committed $8.5 billion to more than 51 investments across each of these five sectors, involving $70 billion of assets.


The Carlyle Group is one of the world’s largest private equity firms, with over 60 funds across four investment disciplines (buyouts, venture & growth capital, real estate and leveraged finance) totaling more than $81.1 billion under management. Carlyle’s more than 575 investment professionals operate out of offices in 21 countries in North America, Europe, Asia, Australia, the Middle East/North Africa and Latin America, covering a wide range of industries (aerospace & defense, automotive & transportation, consumer & retail, energy & power, healthcare, industrial, infrastructure, real estate, technology & business services and telecommunications & media).


About US Renewables Group

US Renewables Group, LLC was formed to manage a series of private equity funds (including USRG Power & Biofuels Fund I, LP and USRG Power & Biofuels Fund II, LP) that acquire, develop and operate renewable power and clean fuel assets. To date, the firm has made investments in geothermal, biomass, solar thermal, landfill methane, ethanol, biodiesel and associated infrastructure, and has approximately $575 million under management. USRG has offices in Los Angeles and New York. For more information, visit


About Rustic Canyon

Rustic Canyon Partners is an early stage venture capital firm that invests in exceptional entrepreneurs building transformational companies. The investment team works collaboratively, drawing on a diverse set of experiences as successful entrepreneurs, managers, and strategic and financial advisors. With over $900 million in funds under management, Rustic Canyon is one of the largest firms based in Southern California, with strong presence in Silicon Valley and Seattle. Key investment themes include Internet/media convergence, clean technology, technology-enabled services, information services, and wireless and wireline broadband. For more information on Rustic Canyon, visit