Dig Energy’s Compact Water-Jet Drill Rig Could Revolutionize Geothermal Heating Costs

Dig Energy Introduces Innovative Compact Drill to Slash Geothermal Installation Costs

On a farm near Manchester, New Hampshire, Dig Energy demonstrated its unconventional water-jet drilling rig, a technology designed to transform geothermal heating and cooling by significantly lowering upfront installation expenses. Operating in stealth for five years, the startup’s compact rig promises to reduce drilling costs by up to 80%, potentially making geothermal systems competitive with traditional fossil fuel heating solutions.

The company recently announced a $5 million seed funding round led by Azolla Ventures and Avila VC, with participation from several other investors including Baukunst and Conifer Infrastructure Partners. This capital will support the transition from prototype testing to commercial pilot deployments.

Addressing the High Cost Barrier in Geothermal Adoption

Heating and cooling account for approximately one-third of energy consumption in the U.S., and this figure rises to nearly 40% in data centers. Geothermal systems offer a path to reduce HVAC energy use and can save grid operators billions annually. According to the Oak Ridge National Laboratory, meeting U.S. electrical grid demands will require drilling six million feet of geothermal borehole daily through 2050.

Despite these benefits, geothermal technology has maintained just a 1% market penetration in U.S. buildings, primarily due to prohibitive upfront costs. Dig Energy’s CEO Dulcie Madden emphasized that the challenge lies in the initial installation expenses rather than operational costs, which remain low.

Focusing on Shallow Geothermal with a Novel Drilling Approach

Geothermal installations are broadly categorized into enhanced geothermal systems that reach deep, hot rock for electricity generation, and shallow geothermal systems used for heating and cooling buildings by tapping into steady subsurface temperatures. Dig Energy concentrates on the latter, drilling to depths of a few hundred feet where the ground temperature remains stable year-round.

The core innovation is a water-jet drilling rig that uses high-pressure water instead of traditional cutting bits. This method not only reduces rig size but also delivers straighter boreholes, allowing for closer spacing of ground loops, which can enhance system efficiency and reduce the land footprint.

Compact Design Enables Access and Cost Reduction

Current geothermal drill rigs are large, truck-mounted machines that struggle to access tight urban or residential sites. Dig Energy’s prototype, significantly smaller than conventional rigs, can navigate constrained spaces such as backyards or crowded commercial lots. While still in prototype stage, the rig has successfully drilled through diverse soil and rock types including sandstone, granite, and shale.

The company plans to slightly increase rig size for commercial use but aims to avoid reliance on large trucks, facilitating easier deployment. Dig Energy intends to market these rigs to drilling contractors, broadening the availability of affordable geothermal drilling options.

Unlocking the Untapped Geothermal Market

Co-founder Dulcie Madden highlighted the vast potential for geothermal expansion, noting that the technology currently serves only 1% of buildings despite its advantages. By lowering the cost barrier and simplifying access to drilling equipment, Dig Energy envisions geothermal heating and cooling becoming standard in virtually all buildings.

“We shouldn’t have to require people to buy a $2 million rig,” Madden said. “Geothermal should be in 100% of buildings. It’s in 1% of buildings. So how do we close the 99%? It’s effectively an untapped market.”