How it works

- Electricity is produced by “on grid” photovoltaic equipment (meaning that surplus energy is injected into the national grid, while the grid feeds the house when there is no sunlight)
- Overall electricity consumption is estimated at 3 MWh / year
- The 44 panels (72 sqm) generate 12 MWh / year
- The 9 MWh / year surplus provides an income of 2500 euros annually from the sale of electricity and the government green certificates program

- Climate control is done via a low temperature heating – cooling system in the walls and ceiling
- Thermal energy is collected by 16 solar panels of 2.3 sqm each and stored in an underground heat storage
- Hot water is prepared using the hot (central) zone of the underground storage
- The 16 solar panels (~ 36 sqm) generate 18 MWh of thermal energy per year
- Of this amount, 6 MWh is taken directly from the panels and used for heating and hot water
- The 12 MWh surplus is stored underground and ensures the 3 MWh heat requirement that the panels cannot fulfill during winter