For owners of a PV system it is important to be able to use as much of the electricity they have generated themselves as possible – it makes sense both environmentally and economically,” explains Martin Hackl, head of Solar Energy at Fronius International GmbH. Fronius has already developed solutions that mean that, during sunny months, the batteries of the household energy system are always full, the electric car is fully charged and even the water is heated using PV energy.
Saving energy and fuel costs with the Fronius Ohmpilot
The Samwald family in Steinbach, Austria, has been using a 4-kWp PV system to supply the six-strong household with energy since 2014. For the father, Stefan Samwald, that was not enough. Tucked away in the cellar was an old oil heating system. It was over 20 years old and had to be kept running during the summer in order to heat the hot water. So, he decided to fit a Fronius Ohmpilot. This device directs excess PV energy straight to the heating element in the boiler.
From spring to autumn, all of the hot water the Samwald family uses can be heated using excess solar energy from their own roof. During that time, their oil heating system gets a well-deserved break. This protects the system, increases its service life and reduces fuel consumption. By using clean solar energy, the Samwalds saved 430 litres of heating oil in 2017. Over the same period of time, the rate of self-consumption increased from 30% to more than 60%, even reaching 90% on some occasions.
90% self-sufficient thanks to hot water, batteries and e-mobility
The Auer family in Rieden also relies on Fronius energy sector integration know-how. The Ohmpilot not only allows them to heat water using solar energy, but the 16-kWp roof-mounted system also feeds a Fronius Solar Battery and an eCharge wallbox for their electric car. The Auer family can even use the energy they have stored after sunset, thus increasing their energy self-consumption considerably. This system allows the Auer family to achieve an impressive 90% rate of self-sufficiency, which decreases their energy costs and shortens the payback period of the PV system considerably.
