The Carlyle/Riverstone Renewable Energy Infrastructure Fund, US Renewables Group and Rustic Canyon Partners have invested a total of $41.5 million (€28 million) in Santa Rosa, California-based ThermaSource.
ThermaSource is a provider of drilling, engineering and consulting services to the renewable geothermal energy sector. The financing will fund the acquisition of geothermal drilling rigs and the development of services associated with those rigs: engineering, mud-logging, cementing and exploration.
Employment is expected to double by year-end to more than 420 people as the result of domestic and international expansion.
The Carlyle Group and its affiliate Riverstone Holdings joined US Renewables to make ThermaSource’ initial equity investment of $20 million in February 2007. Carlyle and Riverstone invested though GRR Holdco, an affiliate that owns geothermal drilling rigs.
ThermaSource has raised $93 million of equity and debt over the course of two years.
Riverstone, a New York-based energy- and power-focussed private equity firm, and Carlyle jointly sponsor the Riverstone/Carlyle energy funds.
The firms closed the first Carlyle/Riverstone Renewable Energy Infrastructure Fund in 2006 on $685 million. They are currently raising the fourth Carlyle/Riverstone Global Energy and Power fund targeting $6 billion, according to the Probitas Partners 2008 Private Equity Deskbook. The third fund closed on $3.8 billion in 2006.
US Renewables Group, based in New York and Los Angeles, has approximately $575 million under management for investment in renewable power, biofuels and clean technology infrastructure. USRG Power & Biofuels Fund II closed on $475 million in July 2007 and has partnered with Riverstone and Carlyle on several investments.
Early-stage venture capital firm Rustic Canyon has more than $900 million under management for investments in: cleantech, broadband, digital media, technology-enabled business process outsourcing and business information services.