Solar energy in Finland
Solar energy in Finland is used primarily for water heating and by the use of photovoltaics to generate electricity. As a northern country, summer days are long and winter days are short. Above the Arctic Circle, the sun does not rise some days in winter, and does not set some days in the summer. Due to the low sun angle, it is more common to place solar panels on the south side of buildings instead of on the roof. Mounting them vertically reduces the average output by 22% from mounting at a 60° angle.
Photovoltaics
The PV capacity of Finland was 11.1 MWp. Solar power in Finland was 1 GWh, 2 GWh and 3 GWh. There has been at least one demonstration project by the YIT Rakennus, NAPS Systems, Lumon and City of Helsinki in 2003. Finland is a member in the IEA's Photovoltaic Power Systems Programme but not in the Scandinavian Photovoltaic Industry Association, SPIA.In 2015, the Kaleva Media printing plant in Oulu became the most powerful photovoltaic solar plant in Finland, with 1,604 solar photovoltaic units on its roof. Although the city of Oulu, located near the Arctic Circle, has only two hours of weak sunlight in December, the photovoltaic cells work almost around the clock in the summer. The cold climate means the PV panels can get up to a 25% boost per hour, as they don't overheat.
Because the sun is quite low in the sky at this latitude, vertical PV installations are popular on the sides of buildings. These solar walls also capture light reflected from snow.
Snow is not necessarily cleared from rooftop solar installations.