Four billion years ago, Earth was a fiery, tumultuous world of molten rock, volcanic eruptions, and toxic skies, with searing heat and the constant threat of asteroid impacts.

Thankfully, our planet has cooled off a bit since then. Nevertheless, the Earth still radiates vast amounts of geothermal energy. It’s a clean, limitless, always-on power source lying beneath our feet — we just have to dig for it. Or get robots to do the hard work for us. 

Borobotics, a startup from Switzerland, has developed an autonomous drilling machine — dubbed the “world’s most powerful worm” — that promises to make harnessing geothermal heat cheaper and more accessible for everyone. 

“Drilling will become possible on properties where it would be unthinkable today — small gardens, parking lots, and potentially even basements,” Moritz Pill, Borobotics’ co-founder, tells TNW.  

At just 13.5 cm wide and 2.8 metres long, the compact boring robot can silently burrow just about anywhere. It could make geothermal a viable backyard energy source.

The machine — nicknamed “Grabowski” after the famous cartoon mole — is the world’s first geothermal drill that operates autonomously, according to the startup. Sensors in Grabowski’s head mean it can detect which type of material it’s boring through. If it bumps into a water spring or gas reservoir on its way down, the robot worm automatically seals the borehole shut. And unlike the diesel-powered drills typical to the industry, the machine plugs into a regular electrical socket. 

However, Grabowski’s humble frame has a few drawbacks. The device is less powerful than bigger rigs. It’s also slower and can only dig to a maximum depth of 500 metres. But for Borobotics’ target market, that’s more than adequate, it says.

Limitless heat just below our feet 

While most geothermal startups look to produce utility-scale electricity by digging many kilometres below the Earth’s crust, Borobotics is going shallow. 

“In many European countries, at a depth of 250 metres, you have an average temperature of 14 degrees C,” says Pill. “This is ideal for efficient heating in winter, while still being cold enough to cool the building in summer.”

Borobotics wants to tap the burgeoning demand for geothermal heat pumps. These devices use a network of subterranean pipes to transfer heat from below the ground to a building on the surface. Under the right conditions, they double-up as air conditioning. 

Heating and cooling buildings accounts for half of global energy consumption, the lion’s share of which comes from burning fossil fuels like natural gas. 

To curb emissions, the EU has committed to installing 43 million new heat pumps between 2023 and 2030, as part of the bloc’s €300bn REPowerEU plan. 

The advantages are obvious. Heat pumps use electricity instead of fossil fuels to transfer heat or cold air. They are up to three times more efficient than the equivalent gas boiler. If they plug into a renewable energy source, even better. 

The EU backs both geothermal and air-source heat pumps, but the latter dominate thanks to lower costs and easier installation. That’s despite geothermal heat pumps being more efficient because they rely on stable subterranean heat rather than fluctuating outdoor temperatures.

“The potential of geothermal heat pumps to decarbonise Europe is substantial, as long as the cost comes down,” Torsten Kolind, managing partner at Underground Ventures, tells TNW. “The minute that happens, the market is open.”

Underground Ventures, based in Copenhagen, is the world’s first VC dedicated entirely to funding geothermal tech startups. The firm led Borobotics’ CHF 1.3mn (€1.38mn) pre-seed funding round, announced this week.

Due to their small size, Borobotics says its drill is “very resource efficient” to produce and maintain. What’s more, Grabowski’s autonomous capabilities, other than being cool, have a hidden advantage. 

Pill paints the following picture:

“A small team arrive to a site with a Sprinter van containing everything necessary to drill,” he explains. “They set the drill in half a day and from then on it works autonomously.” 

Pill predicts that one or two people will be able to handle 10-13 drill sites simultaneously. If correct, this means drilling companies can cover more ground in less time, even if Grabowski is a little more sluggish than its fossil-fuelled relatives. 

Given the EU’s chronic shortage of heat pump installers, an autonomous drilling robot may be a welcome helping hand.  

Despite the apparent potential, it’s still early days for Borobotics. Founded in 2023, the company is currently developing its first working prototype. Fuelled by its first major pot of funding, it looks to test the robot in real conditions this year. 

Geothermal tech is heating up   

In December, the International Energy Agency (IEA) released its first report on geothermal energy in over 10 years. In the report, the IEA predicted that geothermal could cater to 15% of global energy demand by 2050, up from just 1% today. 

Geothermal projects of old were largely state-led, and confined to volcanically active regions like Iceland or New Zealand where hot water bubbles at or near the surface. But the next wave of installations looks to be led by startups armed with state-of-the-art technology that allows them to dig deeper and more efficiently.

Geothermal energy startups attracted $650mn in VC funding in 2024, the highest value ever recorded, according to Dealroom data. One of those is US-based Fervo Energy, backed by Bill Gates’ Breakthrough Energy Ventures. Google has already plugged into Fervo’s geothermal plant in Nevada to power one of its data centres. Another upstart is Canada’s Eavor, which is currently building a giant underground “radiator” in Germany that could heat an entire town.

“The problem has always been geology and economics, but the advances of startups like Fervo and Eavor in recent years have changed the game,” says Kolind.

While US startups are leading the pack, Europe is well poised to compete. 

“Europe has excellent geothermal subsurface conditions, and, unlike America, it also has a strong tradition for district heating,” says Kolind. The investor believes it’s only a matter of time before Europe’s investors and policymakers go all-in on geothermal tech. 

“Unlike natural gas and coal, it is fossil-free. Unlike wind and solar, it is always-on. And unlike nuclear energy, it is geopolitically benign,” he says.