Finland prepares to require solar panels on new buildings

Finland is preparing legislation that would require solar panels on new detached houses and public buildings when installing them is economically viable, Yle reports. The requirement would be introduced gradually over the next four years.

Building plans would have to include a calculation of the solar system’s cost-effectiveness, according to Jani Kemppainen, an expert on technical regulations at the Finnish Construction Industries association. The calculation would consider factors such as the building’s energy needs, the direction of the plot and the slope of the roof.

The law would not set a minimum number of solar cells or panels. If the calculation shows that installing a solar energy system would not be financially viable, it would not be required.

From the beginning of 2027, the requirement would apply to new public buildings with a ground-floor area of more than 250 square metres, including retail premises. It would later be extended to larger and existing public buildings, and to new detached houses toward the end of the decade.

Kemppainen said the reform could eventually affect land-use planning, with more attention likely to be paid to building angles and structures that make the best use of sunlight.

Solar power is already being installed at construction and renovation projects. The Puuvilla shopping centre in Pori has 3,001 solar panels on its roof terraces and parking area.

The system produces about 675 megawatt-hours of electricity a year, saving the shopping centre an average of 65,000 euros on its electricity bill. It covers about five per cent of the centre’s annual electricity needs.

The first panels were installed on Puuvilla’s bitumen roof in 2017. Six years later, the shopping centre added more panels in its parking area. The solar installation covers about 4,500 square metres and reduced the number of parking spaces by 150.

Puuvilla property director Ville Mattila said the system had operated without problems. Maintenance and operational inspections are carried out annually, and he described their costs as reasonable. The payback period for the million-euro investment is nearing completion, after which the installation’s full financial benefit is expected to begin.

The solar power requirements are part of a new law on the energy efficiency of buildings. The proposal was circulated for comments last spring and is based on the European Parliament and Council directive on the energy performance of buildings.

The legislation was originally expected to be ready by the end of May. Kemppainen said the Ministry of the Environment is aiming to submit the bill to Parliament in mid-September.