Calpine Celebrates 65 Years of The Geysers

Commemorating Over Six Decades of the People, Power and Progress at the World's Premier Geothermal Resource

MIDDLETOWN, Calif., Oct. 13, 2025 /PRNewswire/ -- Calpine Corporation today announced the 65th anniversary of The Geysers, one of the world's largest and most productive geothermal energy sites. This milestone reflects more than six decades of innovation, partnership and sustainable power generation in Northern California.

Since commercial operations began in 1960, The Geysers has been at the forefront of California's energy transformation, producing reliable, around-the-clock renewable power using steam heated by the Earth's core. Today, Calpine's 13 geothermal power plants across the 45-square-mile terrain generate enough renewable electricity to power approximately 725,000 homes annually.

At the heart of The Geysers' success are the people who develop, operate and maintain geothermal production. Calpine has nearly 300 employees and 150 contractors who live and work in Lake and Sonoma Counties.  Their expertise and dedication to their craft have helped make The Geysers a global model for responsible geothermal development and a cornerstone of California's renewable energy portfolio.

"The success of The Geysers over the past 65 years is a testament to the people who have cared for it: hardworking, committed individuals who view stewardship as both a duty and a privilege," said Aimee Blaine, Calpine's Senior Vice President, Geothermal Region. "Together with our partners and community, we have built a deep connection to each other and this land. Our shared pride in this work has helped The Geysers remain a global leader in geothermal energy production and environmental responsibility."

To commemorate the special milestone, Calpine donated $65,000 to the Clear Lake Environmental Research Center (CLERC), a community-based non-profit focused on protecting and restoring the Clear Lake watershed and surrounding ecosystems. Working across Lake and Sonoma Counties, CLERC coordinates wildfire prevention and habitat restoration efforts. CLERC brings together science, education and collaboration with local partners and tribes to build a more resilient and sustainable future for Northern California.

"The Geysers has shown what's possible when innovation and stewardship go hand-in-hand," said Will Evans, Executive Director and Co-Founder of Clear Lake Environmental Research Center. "Calpine's continued investment in the community reflects a shared commitment to protecting the ecosystem that makes this region so extraordinary."

"Pumping out enough affordable clean energy to power more than 725,000 homes, The Geysers are truly a feat of engineering and dedication," said California State Senate President pro Tempore Mike McGuire. "And Calpine's commitment to expanding renewable energy while protecting our natural resources is proof that innovation and sustainability are perfect partners in the world's 4th-largest economy. 65 years is an incredible milestone for geothermal energy here in Lake and Sonoma counties, and we all look forward to what's ahead as the iconic Geysers continue to help shape California's transition to clean energy for the next generation."

About Calpine:
Calpine Corporation is America's largest generator of electricity from natural gas and geothermal resources with operations in competitive power markets. Our fleet of 79 energy facilities in operation represents over 27,000 megawatts of generation capacity. Through wholesale power operations and our retail businesses, we serve customers in 22 states and Canada. Our clean, efficient, modern and flexible fleet uses advanced technologies to generate power in a low-carbon and environmentally responsible manner. We are uniquely positioned to benefit from the secular trends affecting our industry, including the abundant and affordable supply of clean natural gas, environmental regulation, aging power generation infrastructure and the increasing need for dispatchable power plants to successfully integrate intermittent renewables into the grid. Calpine Corporation is a private corporation owned by a consortium of investors, led by Energy Capital Partners (ECP). This group also includes Access Industries and the Canada Pension Plan Investment Board. On January 10, 2025, Calpine announced entry into an agreement with Constellation (Nasdaq: CEG) under which Constellation will acquire Calpine. If you would like to learn more about Calpine, follow us: Linkedin.com/Calpine.

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SOURCE Calpine Corporation