Finnish regulator flags environmental harm from planned Tahkoluoto power line

The Finnish Permits and Supervision Authority (LVV) has concluded that a proposed overhead power line connecting Tahkoluoto offshore wind farm to Ulvila would cause significant environmental and residential impacts in the Pori archipelago, according to a statement released Monday.

Two route options for the 110-kilovolt transmission line—one following the Saaristotie road and another crossing Kolpanlahti bay—would both disrupt landscapes, marine ecosystems, and property rights, the authority found. The northern Saaristotie alignment would mar scenic views with power poles, while the southern Kolpanlahti route risks altering seabed conditions and water quality with 18 new pylons. Neither option avoids compulsory property purchases entirely.

Residents have pushed for underground or submarine cabling to mitigate harm, but developer Tahkoluoto Offshore dismissed the proposal as financially unviable. “Cabling was examined but proved neither technically nor economically feasible,” said Juho Lappalainen, project development manager at Arenso, the investment firm behind the wind farm expansion. The LVV acknowledged in its opinion that cabling could reduce some environmental impacts, though it was not formally assessed in the environmental impact procedure.

Tahkoluoto Offshore stated it will review the regulator’s decision and public feedback before determining next steps. “We’ll study the authority’s assessment and the extensive comments submitted, then decide how to proceed,” Lappalainen said. The power line is required only if the wind farm’s expansion moves forward; a final investment decision hinges on securing all necessary permits.

The project’s timeline remains unclear. “We’re preparing permit applications to advance the process,” Lappalainen added, declining to specify when a decision might be reached.