A smarter way to charge e-cars

So you have a photovoltaic system on your passive house and an electric car out front? Great – but how can you charge an electric vehicle with as much low-cost solar electricity as possible and avoid using mains power? Susanne and Andreas Pohl dealt with this question directly.

Collage of the house

Creating transparency in energy flow

In 2010, passive house owners with photovoltaic systems were sought for a research project of the Fraunhofer Institute for Solar Energy Systems (Fraunhofer ISE). E-vehicles were also a prerequisite. The aim of the project was to use a home energy management system (HEMS) and smart software to optimise the charging process for the e-mobile so that as much solar power as possible could be used. Another special feature of the project: Along with the HEMS, Fraunhofer ISE also supplied a useful app that clearly displays all energy flows in real time.

Part of the smart system was also a forecast-based algorithm. With its help, the Pohl’s were soon able to charge their leased e-car with the maximum amount of solar power. The system calculated this from several factors, including weather forecasts. Alternatively, immediate charging was possible, but usually with a larger share of grid power. All processes could be conveniently controlled via the app.

“Thanks to this project we became familiar with e-mobility and are now firmly won over.”

For Susanne and Andreas Pohl, participation in the project was a win on several levels. They both discovered the fun of driving an electric car. In addition, they now always have an eye on the energy flows – and make optimum use of the added economic and ecological value of their passive house thanks to transparent figures.

At a glance: The project in figures

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Susanne & Andreas Pohl with child

Four questions for Susanne and Andreas Pohl

Your greatest motivation?
To tap into the advantages of photovoltaics and e-mobility with scientific support.

The biggest challenge?
To adapt one’s own behaviour to an efficient use of energy.

Your personal highlight?
Getting an electric car and driving for the first time.

Your insiders’ tip?
We can highly recommend participating in scientific projects on energy efficiency.

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