Finnish electrical networks are not a bottleneck in utilising solar electricity potential

The Finnish electricity distribution system has significant possibilities for receiving increasing small-scale solar electricity production. According to a study conducted by Lappeenranta University of Technology (LUT), the rooftops of residential buildings could house up to 12 000 megawatts worth of solar electricity systems.

The study revealed that photovoltaic power systems could be installed on a significant number of existing buildings. The roofs of residential buildings alone could house solar electricity systems with a total nominal output of 12 000 megawatts. Taking the orientation of the rooftop installations and their geographic distribution into account, this type of solar electricity system could produce a peak power of 7000 megawatts. The peak consumption in Finland is roughly 15 000 megawatts.

"The Scandinavian electricity distribution infrastructure has traditionally been considered strong due to the demanding heating requirements during the winter. Now this network capacity enables a significant number of small-scale customers to feed electricity into the grid," says Post-doctoral Researcher Jukka Lassila

The study modelled the Finnish building stock from the perspective of solar electricity production. The modelling took into account the geographic location, orientation and rooftop area of the buildings. This was done to determine how great a power surge solar electricity could cause and how the grid could withstand it if the roofs of buildings were harnessed for the production of solar electricity on a large scale. The research focused especially on residential buildings, the total number of which in Finland is over 1.3 million, composing a roof surface area of approximately 240 square kilometres. The total number of buildings in general exceeds 5 million, which corresponds to roughly 690 square kilometres of rooftop surface.

The researchers point out that they are not attempting to prove that solar electricity as such could fully cover electricity consumption in Finland. However, the results of the research indicate that the current system has a significant capacity available for the integration of small-scale production.

Nevertheless, the significant transmission capacity does not eliminate the occurrence of individual faults in the grid. Especially in sparsely populated rural areas, the efficient harnessing of residential buildings and rooftops in the vicinity could in some cases raise the solar electricity production capacity and momentary power production to exceed the resident's connected load. This could manifest as voltage faults and grid overloading. Cutting the power surges of the peak production times or ultimately increasing the connected capacity could provide a solution.

Further information:

Jukka Lassila, Post-doctoral Researcher, jukka.lassila@lut.fi, +358 50 537 3636