Sage Geosystems

Sage Geosystems was founded in 2020 in Houston, Texas by Cindy Taff, who serves as co-founder and CEO. Taff brings over 35 years of oil and gas experience from Shell, including a senior leadership role as VP of Shell's global Unconventional Wells operations, where she led more than 350 staff and 1,200 contractors across five countries. Sage operates from Houston, leveraging the same subsurface expertise, workforce, and drilling infrastructure that built the American energy industry to access geothermal resources at commercial scale. The company has two core technology pillars — geothermal electricity generation and subsurface energy storage — making it one of very few developers that pursues both functions from a single geothermal well.

Sage was founded on the conviction that geothermal energy has been dramatically underdeployed relative to its potential, and that oil and gas expertise is the key to unlocking it at scale. Its core innovation is the Geopressured Geothermal System (GGS), which uses a "huff-and-puff" approach to pump and store water in deep, hot subsurface fractures. When released, the pressurized water drives a turbine to generate electricity — functioning simultaneously as a power plant and a long-duration "earthen battery" capable of storing energy from wind and solar. Taff's stated mission is to make these GGS technologies a commercial reality, with the technology serving as an essential step in developing reliable, clean baseload power and grid-scale storage.

Sage is an independent private company. In February 2024 it raised $17 million in Series A funding. In early 2026, Sage announced a ~$100 million Series B anchored by a strategic equity investment from Ormat Technologies — the world's leading geothermal operator — which also carries rights for Ormat to develop, build, and own plants using Sage's technology following a successful pilot. Earlier investors include Helmerich & Payne, Virados Ventures, and Nabors Industries.

Sage completed a full-scale commercial pilot at San Isidro, Texas in 2023, creating a 3,200-foot subsurface reservoir in an abandoned gas well. Its first commercial facility — a 3 MW geopressured geothermal energy storage project at San Miguel Electric Cooperative in Texas — became the world's first such project connected to a utility grid. In 2025, Sage signed a landmark partnership with Meta for up to 150 MW of geothermal baseload power. CEO Cindy Taff was named to TIME100 Climate 2024 as one of the world's most influential climate leaders in business.