Dornbirn couple supplies home with rainwater and solar power

A couple in Dornbirn has become largely energy self-sufficient by using solar power, wood from their own forest and a rainwater cistern, ORF reports. The system has supplied 360,000 litres of water for household use over the past three years.

The family’s roof is covered with photovoltaic panels that provide most of its electricity. Rainwater from the cistern is used to flush both toilets, run the washing machine and water the garden.

Reinhard Nenning, an electrical engineer, said the system helps the family avoid using drinking water for toilets and garden irrigation, particularly during dry summers when local water shortages can occur. The rainwater is soft, which helps prevent limescale in the washing machine.

A technician, Stefan Lutz, developed a digital monitoring and control system for the cistern. It measures the water level and can automatically add drinking water if supplies run low. This has happened only once in three years, and the system adds water only to a limited level to keep it operating.

The family advises anyone planning to use rainwater to contact their local water utility first.

Rain is becoming less frequent but more intense, making it important to collect water quickly. Around 6,000 litres can flow into the cistern during two hours of heavy rain, according to Nenning. That amount is enough to last about four weeks.

The photovoltaic system covers the family’s electricity needs from March until late October, including power for an electric car, a heat pump and the rest of the household. In winter, a wood gasifier provides additional energy, using firewood from the family’s own forest.