Nearly half a century ago, the US Department of Energy launched a clean energy experiment beneath the University of Minnesota with a simple goal: storing hot water for months at a time in an aquifer more than 100 metres below ground.
The idea of the seasonal thermal energy storage was to tuck away excess heat produced in summer, then use it in the winter to warm buildings.
Now, 45 years after the first test wells were drilled under the university’s St Paul campus, one of the first large-scale aquifer thermal energy systems in the country is being built less than 10 miles from the original test site.
The Heights, a mixed-use development rising from a former golf course on the city’s Greater East Side, will tap thermal energy from an aquifer 100 to 150 metres below ground.
Groundwater from wells spread across the northern half of the 45-hectare development will be drawn by high-efficiency electric heat pumps, powered in part by solar panels, to provide low-cost heating and cooling with little greenhouse gas emissions for 850 homes and several light-industrial buildings.
Continue reading the article with this 'share link' -> https://www.theguardian.com/environment/2026/jan/29/cheap-geothermal-energy-system-makes-us-comeback-minnesota?CMP=share_btn_url