Geothermal startup Mazama Energy secured $135 million in an oversubscribed Series B to develop horizontal wells capable of generating 15 MW per well.

Mazama Energy, a geothermal startup backed by Khosla Ventures, announced an oversubscribed $135 million Series B round aimed at scaling its proprietary horizontal drilling technology for super‑hot‑rock geothermal projects.

Funding round details

The financing was led by Khosla Ventures with participation from existing investors and several strategic corporate backers. Mazama plans to allocate the capital toward field development, engineering talent, and the construction of pilot wells capable of delivering up to 15 MW each.

Technology focus

Mazama’s approach relies on horizontal drilling into deep, high‑temperature granite formations, a method that could unlock geothermal resources previously deemed uneconomical. By increasing the contact area with the heat source, the company aims to boost power output per well while reducing overall project costs.

  • Horizontal wells designed for 15 MW generation per well
  • Targeting granite formations with temperatures above 350 °C
  • Leveraging advanced drilling rigs and real‑time downhole monitoring

Market implications

If successful, Mazama’s technology could accelerate the deployment of baseload renewable power in regions lacking conventional hydro or solar resources. Analysts note that deeper, hotter geothermal reservoirs have long been a missing piece in the clean‑energy puzzle.

The company’s next milestones include drilling its first commercial‑scale well in the western United States and securing additional power purchase agreements to monetize the generated electricity.

For the full story, see TechCrunch coverage of Mazama Energy’s $135 M raise.