Geothermal heat pumps use the steady temperature of the ground to heat and cool buildings. They work well. Drilling the wells is the expensive part. Dig Energy, a startup that spent about five years developing its rig in a New Hampshire barn, says it has a cheaper way, and in September 2026 it announced its first commercial installation.
The job in Boston
Dig drilled boreholes for a geothermal heating and cooling system at 100MAG, a Suffolk Construction innovation hub next to Suffolk’s Boston headquarters. Canary Media reports seven boreholes. Renewable Energy Magazine says drilling began in early August 2026 and took about two weeks, on an active construction site where the work area covered a few parking spaces.
The rig sprays water from a nozzle at 10,000 psi to bore through soil and rock. The drill string stays in the ground and becomes the heat exchanger. CEO Dulcie Madden told Canary Media the method is a known oil and gas practice applied to geothermal for the first time.
Conventional drilling versus Dig’s approach
| Feature | Conventional rig | Dig’s rig |
|---|---|---|
| How it cuts | Grinds through rock | High-pressure water jet |
| Casing | Needed | None, so the hole can be narrower |
| Drill string | Removed | Left in the ground as the heat exchanger |
| Cost (company claim) | Baseline | Up to 80% lower drilling costs, unverified |
| Water and spoil (CEO’s statement) | Baseline | One-tenth the water, 75% less material hauled away |
Dig replaces the cheap nozzle on each hole. The cost figure is a claim: Canary Media says the company claims up to 80% lower drilling costs, the companies declined to share specific figures, and Renewable Energy Magazine gives no dollar comparison. No independent party has verified it.
Where it falls short
This is one project. A single office-building job does not show how the method performs across different soils, rock types and depths, and borehole depth was not reported. The water and spoil numbers are single-project statements from the CEO, not measured studies. Noise is anecdotal too: Madden said workers could talk near the rig and nearby buildings did not hear it, but no decibel readings were published.
Market context is also an estimate. Madden puts the share of U.S. buildings using geothermal heating and cooling at only about 1%, and Canary Media notes geothermal can cost up to five times as much as an equivalent air-source heat pump. Dig’s first customer is a commercial building, and its stated next jobs are a grocery store, a utility headquarters and a small campus. Nothing here shows lower bills for homeowners yet.
Why It Matters to You
If the cost claim holds up, cheaper drilling could eventually make geothermal heating and cooling more realistic for ordinary buildings. For now, the benefit is not direct. The first job was a commercial building, prices have not been published, and Dig’s announced next projects are also commercial. Businesses and institutions would feel any savings first, and a homeowner offer is unconfirmed.
Quick answers
Does this make geothermal affordable for homeowners?
Not yet. The first job was commercial, and Dig has not published prices. Its announced next projects are also commercial. A homeowner offer, if one comes, is unconfirmed.
How is this different from normal geothermal drilling?
Conventional rigs grind through rock and need casing. Dig uses a high-pressure water jet, leaves the drill string in the ground as the heat exchanger, and replaces the cheap nozzle on each hole.
Who backs Dig?
Suffolk Technologies, the venture arm of Suffolk Construction, invests in Dig through its Boost accelerator. Canary Media also reports Dig announced a $5 million funding round about a year earlier.
When will the next Dig projects happen?
Canary Media reports Dig is booked until mid-summer 2027 and is developing a new rig version aimed at reducing drilling time.
Sources
- Canary Media: Dig Energy completes first project with novel geothermal drilling tech (accessed Oct 13, 2026)
- Renewable Energy Magazine: Dig Energy completes its first commercial installation (Sep 11, 2026)