Kalisz Embarks on Geothermal Revolution: 1,700-Meter Well to Unlock Network of Thermal Pools, Heated Apartment Blocks, and Homes
In the heart of Poland’s Greater Poland Voivodeship, the historic city of Kalisz is taking a bold leap into the renewable energy future. On February 25, 2026, city authorities signed a landmark contract to drill an exploratory geothermal well reaching 1,700 meters deep. The project, dubbed “Kalisz GT1,” aims to confirm the presence, quality, temperature, and productivity of thermal waters beneath the city — potentially transforming Kalisz into a hub for low-carbon district heating and a network of therapeutic thermal pools.
The headline-grabbing Polish announcement — “Sieć basenów termalnych, ogrzane bloki i domy. Miasto drąży odwiert na 1700 metrów” — perfectly captures the ambition: a geothermal-powered network of thermal baths, heated residential blocks, and family homes. If successful, this could slash heating costs, improve air quality, and boost tourism, following the successful model of nearby Uniejów.
A Historic Moment for One of Poland’s Oldest Cities
Kalisz, one of Poland’s oldest continuously inhabited cities with roots dating back over 1,800 years, has long rumored to sit atop valuable geothermal resources in the Mogilno-Łódź Trough geological formation. Residents and officials have spoken for decades about “sleeping on thermal water.” Now, after years of geological studies and grant applications, that dream is becoming reality.
During a press conference at City Hall on February 25, 2026, Mayor Krystian Kinastowski signed the agreement with UOS Drilling S.A. of Warsaw, the winning bidder in a public tender. The contractor, led by President Arkadiusz Biedulski, specializes in deep geothermal and hydrogeological drilling across Poland.
The well will be located on Sportowa Street, right next to the existing Kalisz Aquapark — a strategic spot that will allow easy integration of geothermal heat into recreational facilities if the resource proves viable.
Project Details: Depth, Timeline, and Technology
The exploratory borehole will reach a maximum depth of 1,700 meters, primarily targeting the Lower Jurassic (dolna jura) layer, with additional investigation of Triassic formations. Experts anticipate water temperatures of 40–50°C at this depth — ideal for district heating when combined with high-efficiency heat pumps that can boost output to 70–80°C. Deeper subsurface temperature maps for the region suggest even higher potential: nearly 100°C at 2,000 meters and up to 155°C at 4,000 meters, indicating strong long-term prospects.
Drilling is scheduled to begin in May 2026 and operate 24 hours a day, with the full drilling phase expected to take 2–3 months. Comprehensive follow-up work — including hydrogeological, geophysical, and laboratory testing to determine mineralization, flow rate, pressure, and exact temperature — will continue until May 31, 2027 (or August 2027 in some updated schedules).
Total investment cost exceeds 22 million PLN(approximately €5.1 million). The city secured substantial funding of over 14.5 million PLN from the National Fund for Environmental Protection and Water Management (NFOŚiGW) under the priority program “Unveiling Thermal Waters in Poland.” This grant, awarded in 2024 alongside six other municipalities, covers a significant portion of the exploratory risk.
Vision for Utilization: Thermal Pools, District Heating, and More
Success would open the door to a comprehensive geothermal system modeled on Uniejów, Poland’s flagship geothermal town, which combines district heating with popular thermal baths.
Mayor Kinastowski outlined ambitious plans:
“We assume the captured heat could be delivered to apartments in the Wzgórza Kalisza housing estate and to single-family homes. Geothermal heat would power the Kalisz Aquapark, the Sports, Rehabilitation and Recreation Center, sports facilities around the City Park, and we would expand the network of thermal pools just like in Uniejów.”
Additional applications include heating sports pitches and stadium turf, developing balneotherapy and spa tourism, and even supporting local industry. The primary goal remains integration into the municipal heating network to provide cheaper, stable, and nearly zero-emission heat to thousands of residents.
Biedulski, drawing on his experience with the Polish Geothermal Association, expressed confidence:
> “Even though the temperature is not extremely high, the 40–50°C level expected in the Lower Jurassic layer is perfectly usable for the city’s heating needs… This is a good location for such a project. We can expect all the plans to be confirmed.”
Environmental and Economic Benefits
Geothermal energy offers Kalisz a pathway to decarbonization. By replacing coal and gas in the heating mix, the project could dramatically cut emissions of dust, CO₂, and other pollutants — directly improving air quality in a region still transitioning away from fossil fuels. Kinastowski emphasized the ecological and economic impulse:
“This will bring enormous ecological benefits, including reduction of harmful dust and gas emissions. Geothermal energy is an impulse that will drive the city’s economy.”
For residents, lower heating bills and access to year-round thermal bathing could enhance quality of life. Tourism potential is significant: modern thermal pools and wellness centers attract visitors year-round, as proven in Uniejów and other Polish geothermal destinations.
Poland’s Growing Geothermal Momentum
Kalisz joins a growing list of Polish cities investing in geothermal energy. Successful projects in Uniejów, Poddebice, and deeper wells in Bańska Niżna near Zakopane demonstrate the technology’s reliability for both heating and recreation. The Polish Geothermal Association notes that properly developed resources can provide baseload renewable heat with minimal environmental footprint and high capacity factors.
Exploratory wells like Kalisz GT1 carry risk — flow rates or mineralization could affect economic viability — but the grant structure and careful site selection minimize downside. If results are positive, the city plans a second injection well to create a closed-loop sustainable system.
Looking Ahead: Geothermal Era for Kalisz?
Results from the well and associated studies will be available by mid-to-late 2027. Positive findings would trigger detailed feasibility studies for full-scale development, including heat exchangers, distribution networks, and potential expansion of the Aquapark with outdoor thermal pools.
For Kalisz, this is more than infrastructure — it’s a strategic bet on energy independence and sustainable growth. As Mayor Kinastowski noted at the signing:
“From childhood I heard that thermal water is under Kalisz, that we sleep on it. Now the time has come to check it.”
Poland’s energy transition, supported by EU Green Deal funding and national programs, is accelerating. Cities like Kalisz that act decisively today will lead tomorrow’s low-carbon economy.
Stay tuned for updates as drilling begins in May 2026. Will Kalisz join the ranks of Poland’s geothermal success stories? The 1,700-meter journey into the Earth could redefine the city’s future — delivering warm homes, relaxing thermal pools, and cleaner air for generations to come.
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What are your thoughts? Could geothermal be the answer for mid-sized Polish cities? Share in the comments and follow for drilling updates!

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