The combined output of solar energy in Finland has increased by a factor of 10 in five years, as the use of solar panels on private properties has grown, says one power grid operator.
Privately installed solar panels installed currently produce 277 megawatts (MW) of electricity, compared to just 27 megawatts at the end of 2016. The growth in output became more evident as it rose to 66 MW at the end of 2017, 120 MW at the end of 2018 and 198 MW at the end of last year.
Although that output includes business premises, the vast number of private installations are in detached homes and summer cottages.
"On the basis of the power [output) you could estimate that close to 50,000 homes or cottages have solar panels," development manager Jonne Jäppinen of power grid firm Fingrid said.
Electricity grid transfer companies have accurate information about small power generators in their areas, because they have to sign agreements with such companies to join the grid.
Among the largest grid companies, Caruna has 8,800 such customers, while Elenia has 5,500 and Suur-Savon Sähkö has 1,500 -- all of whom use solar power to generate electricity for their private consumption and also sell excess power to the grid.
Electricity for domestic use and local power grid
As the trend gains ground, many households have acquired solar panels, usually installed on rooftops. One such homeowner is Savonlinna resident Jouni Koskela, who installed his household solar power plant in spring 2019.
Koskela paid just under 10,000 euros for the installation, an amount that fell to around 8,000 euros after the family claimed the investment as a household expenses tax credit. The Koskelas have said that they are cautiously optimistic about the acquisition.
"It looks like it won’t pay for itself in 10 years, but we are definitely pleased about it. If we can use more of the output ourselves, then profitability will improve," Koskela said.
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The family home has 18 solar panels deployed over about 30 square metres. So far they have absorbed the equivalent of 3,500 kilowatt hours (kWh) from the sun. The family has used 850 kWh and sold the remaining 2,600 to the local power company.
The actual value of the energy used by the family is an estimated 13 or 14 cents, because the real savings comes from cutting back on electricity costs as well as electricity transfer costs and taxes. Extra electricity produced is sold at the going rate, which is an average of about five cents per kilowatt hour.
Since the installation, the Koskelas have used an estimated 130 euros of electricity. They earned a similar amount from the surplus sold to the power company. The rooftop solar plant therefore produced about 260 euros of electricity in its first year of operation.
"In the future, we could warm water during the day when the sun is shining. We could also make better use of a hybrid car when the sun is out," Koskela said.
The family will eventually be able to hike output from the solar panels, having received permission from city authorities to fell three large trees casting a shadow over the property.
From eco statement to profitable investment
Jero Ahola, electrical engineering professor at Lappeenranta-Lahti University of Technology, said that the Koskelas' energy output was quite typical. He noted that household solar panel owners can shorten the payback time of the investment by consuming as much of their output as possible.
However one challenge of hiking domestic electricity consumption is that solar panels tend to produce the most power at times when the need for electricity is at its lowest.
"If in the past solar panels were an ideological choice, today it’s more of a financially profitable investment," Ahola noted.
Advocates of the energy source have long touted it as a better alternative to wind energy. Many in Finland stubbornly hold to the notion that solar power cannot pay off in the cold, dark north. However the facts tell a different story.
"Even in the best areas [for solar power] in Chile you will get just two, two-and-a-half times more power than here. We also have a cold climate and the fact that the sun shines at an angle is an advantage," Ahola pointed out.
The professor noted that investing in solar power also increases property values. He also shared a tip for people considering taking the plunge and spending on solar panels.
"It would be useful to get a large enough system at once and to install a lot of panels on the roof. That way the unit price of electricity will be cheaper. Our research shows that a five-kilowatt installation provided the shortest payback period," Ahola concluded.