Record-breaking geothermal drilling reaches 1.5 km in Helsinki after delays

A long-delayed geothermal drilling project for Helsinki’s new Laakso Joint Hospital has finally progressed to 1.5 kilometres, the hospital announced, though the work remains behind its original schedule.

The ambitious project, intended to create Finland’s deepest water-hammered geothermal well at 3.5 km, faced setbacks due to extreme cold and supply chain issues, according to a statement from the hospital. Drilling was initially planned for completion by the end of last year.

Harsh winter conditions halted operations, as sub-zero temperatures prevented the water-hammering technique required for the borehole. Additional delays stemmed from missing components needed to install a protective steel casing in the first kilometre of the well, designed to prevent groundwater contamination.

Hospital officials confirmed that all necessary widening drills—required before casing installation—have now been completed, allowing the project to advance without further interruptions. The next update is expected when drilling reaches the 2 km mark.

The €5.9 million contract for the first well includes an option for two additional boreholes at a combined cost of €8.6 million. Any cost overruns will be covered by the contractor, Hanjin D&B. The main hospital building is set for completion in 2027, with broader construction continuing until 2030.

Experts previously questioned the project’s feasibility, suggesting its energy-saving expectations may be overestimated. If successful, the well would become Europe’s deepest of its kind.