ThermaSource, LLC Completes $41.5 Million Private Equity Financing

SANTA ROSA, Calif.--(Business Wire)--
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 www.thermasource.com

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 www.usregroup.com.

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 www.rusticcanyon.com

Andersen & Company LLP
Ted Grafe, 707-524-6523
grafepr@aandco.com
or
ThermaSource, LLC
Louis E. Capuano, Jr., 707-636-5808
lcapuano@thermasource.com

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