Located within the Cascade Range of mountains, Newberry is one of the largest geothermal reservoirs in the US.  

Unlike conventional geothermal systems, which rely on natural permeable hydrothermal reservoirs underground, EGS uses advanced drilling and stimulation techniques to create engineered reservoirs in hot, impermeable rock, unlocking geothermal resources beyond conventional limits, says the company.

EGS is the key to tapping a renewable energy source that is abundant but currently inaccessible in many regions, explains Sriram Vasantharajan, CEO of Mazama Energy.  

Building on hydraulic fracturing principles used in the oil and gas industry, Mazama’s ‘Thermal Lattice’ technique induces a complex network of thermally stable fractures, improving reservoir connectivity and heat recovery while maintaining wellbore integrity under extreme thermal stress. Real-time fibre-optic monitoring, chemical and nanoparticle tracers, and crosslinked fracturing fluids were employed to map fracture propagation and assess reservoir performance.

Mazama says it achieved a number of record performance metrics during drilling: peak penetration rates of 100 ft/h, average rates of 76 ft/h across diverse rock types such as granite and basalt, and bit runs of up to 2,760 ft through volcanic formations, without a single downhole equipment failure.

The company now plans to scale up operations, beginning with a 15 MW demonstration in 2026, followed by a 200 MW development project at Newberry. Mazama also plans to extend operations into the ‘superhot rock regime’ – above 400°C.