If you are a startup company developing a drilling technology to overcome one of the big obstacles in the energy transition, you might as well do it where everything is more difficult, right?
In other words, do it in New Hampshire.
“New Hampshire has notoriously difficult geology. If we can drill in New Hampshire, we can drill anywhere,” said Dulcie Madden, a Hopkinton native who is the co-founder and CEO of Dig Energy, headquartered in the Manchester Millyard and a Derry machine shop.
As with geology, the same remains true for finance. “In New Hampshire for energy, it is hyper utilitarian about cost. There are so few incentives,” she said. “If we can make the economics work here, we can make it work anywhere.”
Many Hopkinton residents have long known Madden, who grew up there, moved back with her family in 2018, and is now on the school board. But the nation’s energy sector learned about her this week when Dig Energy finished using high-pressure water rather than traditional rigs to drill seven boreholes for a ground-sourced heat pump in the Boston neighborhood of Roxbury.
Next up: Doing the same for the expanding middle school in Dover, N.H.
The accomplishment is a lot more important than it may sound. Making it cheaper and easier to install ground-sourced heat pumps, which are vastly more efficient than traditional heating and cooling systems, is a major goal of the energy transition.
Electric heat pumps that replace furnaces by moving heat in and out of buildings using the outside air are becoming common. Doing this using the constant temperatures underground, rather than the variable temperature of air, is even better.
But ground-sourced heat pumps require drilling a series of holes a few hundred feet deep to get access to underground temperatures. This makes them many times more expensive to build than air-sourced heat pumps built above ground, which is why they are comparatively rare.
Drilling rigs have long used metal drill bits to grind or pound away dirt and rock when creating narrow, deep holes. Dig Energy’s rig does it with high-pressure water, slurping the water and debris back up to the surface using a jet pump.
Dig claims it can slash the cost of drilling geothermal boreholes by three-quarters, while using much less water, hauling out less material and making a lot less noise.
“We had, oh, 80 visitors come through [the] drill site. You can stand right next to it and have a regular conversation without protection,” Madden said.
The geothermal industry is filled with people who used to work in oil and gas drilling, but neither Madden nor co-founder Thomas Lipoma had an energy background.
Madden got her undergraduate degree in biology with a Master’s in public health. After a stint in India, she went to MIT with the idea of getting an MBA, met Lipoma, a mechanical engineering student, and went through incubator programs.
The two decided on improved borehole drilling as a viable route for an engineering startup, and Dig Energy was created in 2020. The firm has been in the Millyard for a few years and is looking for a bigger space to handle what it hopes will be a major expansion, now that there’s a working site to help lure customers.
The target isn’t individual homes, likely to balk even at a lower price, but certain types of businesses that want to lower operating costs.
“We can see this for multi-family campuses, grocery stores, distribution centers, even data centers,” Madden said. “The goal is to use local suppliers, local manufacturers, and expand as we go.”
The borehole drilling occurred at the Boston headquarters of Suffolk Construction, which learned of Dig Energy because it was selected to participate in Boost, an accelerator program run by Suffolk Technologies, the company’s venture capital affiliate.
