A barn has become an energy-efficient residential building where sun, wind, and wood provide heat and electricity, in Korpo. One family decided to make this idea real and managed that in four years.

Korpo is one of the biggest islands in the Åbo archipelago in Finland with a population of 800 people. The energy-efficient residential building project on the island has been started planning in 2010 and launched in 2014 by the family of Fellman. The main idea of it was to convert barn to an energy-efficient residential building. It has been decided to heat the house with wood and solar panels, and floors with the electricity produced after the batteries become full.  

The family started using the house in 2014. It had a battery bank of 9.9 kW/h and floor heating with a resistance of 1 kW. When the batteries are fully charged, the electricity is used to heat the floors and the battery bank doubles soon. And that is a perfect solution for the sunny part of the year. But from November to February the house requires additional solutions. So, the wind turbine has been installed on the house, and the water heater took advantage of overflow electricity during windy days. Nowadays the house receives more energy than needs.

The house's electrical system is cheaper solution: while the neighbouring house has electricity costs of several thousand euros per year, the electricity consumption in the old barn does not cost.

The electrical system is ordered via a local electrician, who imported the equipment from Canada, the USA, and Europe.

Keywords: private household, energy-efficiency, sun, wind, wood, heating, electricity, Korpo, Finland