ThermaSource
, a Santa Rosa, Calif. provider of drilling, engineering and consulting services to the geothermal energy sector, has raised an undisclosed amount of cash from US Renewables Group, Riverstone Holdings and The Carlyle Group.

From the statement:

Funds will come from USRG and Carlyle/Riverstone Renewable Energy Infrastructure Fund (“CRREIF”) and be used to acquire new and reconditioned drilling rigs. US Renewables Group and Carlyle/Riverstone are making their investment through their affiliate GRR Holdco, LP, an owner of geothermal drilling rigs.