Case: Sakarinmäki School

We designed a renewable energy -based heating solution for the Sakarinmäki School Centre, comprising a combination of ground source heat, solar heat, a heating plant, and heat storage.

Sakarinmäki – pilotschool for renewable energy

Sakarinmäki is a pilot project for us to test new kinds of energy solutions. 100% of the energy used by the school is now generated with renewable energy. Construction of the Sakarinmäki School Centre energy system is the first step of a larger trial in Östersundom.

Right from the start, the pupils and teachers of SakarinmäkiSchool were included in the project to generate ideas on how the new energy solution can also be utilised in learning. We installed screens in the school, allowing heat production to be monitored in real time. You can also view the same information on this page: for example, the figure below shows the school’s heat production for the last 24 hours.

Heat production




Bio oil

Heat production now



Bio oil


Solar collectors collect and store the sun’s heat for heating the school and its hot tap water. Each collector is 2 metres high and 5 metres wide. There are 16 collectors in all, so their total area is 160 square metres. The solar collectors’ production output is 150 kW.

Solar collectors in Sakarinmäki

A geothermal well in Sakarinmäki


A geothermal well is a hole bored to the depth of about 300 metres, with piping inside. The bioethanol circulating in the pipework collects thermal energy from the surrounding earth into heat pumps, and through them for heating the school. There are 21 geothermal wells, and the design output of the heat pumps is 275 kW.


The oil-fired heating plant heats the school when ground source heat and solar heat are not sufficient to cover consumption, in practice in frosty weather. The plant porduces heat from renewable bio-oil. The heat is transferred to the school through a hydronic heat distribution system. The school’s maximum heating requirement is 1,200 kW. The maximum output of the heating plant is 1,500 kW, so that it is designed to cover the school’s heating requirement in all eventualities.

Bio oil powered heating plant in Sakarinmäki


Helen organised workshops for the Sakarinmäki School pupils and teachers to generate ideas on how the renewable energy solution might be utilised in learning.

As a result, almost 300 children of different ages have learned to recognise heating energy consumption and production at school. The production information can be applied to exercises in various subjects, such as maths, physics and Finnish language.

The pupils and teachers were involved in planning how the heating system and production information gleaned from it could be made visible at school in a form that was easy to understand and bolstered learning. The screens installed in the school now allow everyone to monitor in real time how much energy is obtained from ground source heat pump, the solar collectors and heating plant, and what it means, for example converted to warm showers.

Kaisa Alanne, the school’s headmistress, is pleased with the workshops and the entire pilot project.

“We are glad that we have been given the opportunity of piloting a renewable energy -based heating solution. It has got both the pupils and teachers interested in energy issues. We can utilise the energy production information in many subject areas, and energy also ties different subjects together,” Alanne says.

Current heat production as warm showers



Bio oil

= 20 kW