Electric cars feed their electricity back into the grid when they’re not being driven

Can bidirectional charging of electric cars contribute to a sustainable energy future? Daniele Farrace, an engineer at distribution grid operator Azienda Elettrica di Massagno (AEM) in Ticino, has no doubts. He shows how this could work one day.

Text   Daniel Schriber


  • Sustainability

It’s only half past ten in the morning and the sun’s already burning mercilessly from the sky. The thermometer’s reading over 30 Celsius when we meet Daniele Farrace at a Mobility station in Tesserete near Lugano. Not ideal conditions for a video interview – but the 36-year-old from Ticino is smiling despite his shirt and long trousers. “The heat suits the topic.” The temperatures that prevailed throughout Switzerland at the end of August were “above-average” even by Ticino standards, according to the doctor of engineering (ETH). This is the ideal time to talk about the energy transition.

Farrace is the Chief Innovation Officer of distribution grid operator Azienda Elettrica di Massagno (AEM) SA. The company employs some 25 people and serves around 9’000 customers. “We’re small, which is why we need to be innovative and agile,” Farrace emphasises. AEM is the local network operator: at the beginning of the year, the company was awarded the Watt d’Or energy prize. It was singled out for a project in the little village of Lugaggia, where AEM was able to significantly increase the municipality’s consumption of its self-produced electricity thanks to an intelligent networking of electricity consumers and solar producers. For Farrace, awards like this aren’t a reason to sit back – quite the contrary. “The faster we can push ahead with the energy transition, the better.”

Optimising self-produced electricity

Like in Lugaggia, AEM has also linked houses in the municipalities of Massagno and Tesserete to form what’s known in Switzerland as a ‘Zusammenschluss zum Eigenverbrauch’ (ZEV) – an association of electricity producers and consumers. These are groups of households and commercial and recreational facilities that generate and band together to use their renewable energy. This is where the “V2X Suisse” project comes in: the idea behind V2X or bidirectional charging is that electric cars not only consume electricity, but also feed it back into the grid when they’re not being driven. “The technology allows us to store the overproduction from our photovoltaic systems in the cars’ batteries during the day. Then at night, when the PV systems are no longer producing electricity, we feed the energy from the car back into the local grid.” The public electricity grid is only tapped when the available energy has been used up. AEM uses an algorithm to control this process. It estimates the load profiles of the aggregated households based on past consumption data and current weather forecasts. 

Where can I find a V2X car? By March 2024, 50 Honda e cars will be stationed at 40 Mobility locations throughout Switzerland.

E-cars harbour “huge potential”

Daniele Farrace believes strongly in the future of V2X, which is why he’s fully committed to his “V2X Suisse” side-project. Not least because, according to estimates, Switzerland will be home to some two million electric vehicles by 2035. “This trend has huge potential.” For comparison purposes: the Leibstadt nuclear power plant today achieves a nominal output of some 1.22 gigawatts of electrical energy, while two million e-cars have the potential of delivering around 15 gigawatts of electricity. 

As a next step, local grid operator AEM is looking to develop business models together with its partners in the V2X side-project – namely Mobility, Primeo Energie (Zurich city’s electricity utility), the FHNW University of Applied Sciences and Arts Northwestern Switzerland, and the OST University of Applied Sciences of Eastern Switzerland – to ensure the economic viability of the V2X model going forward. Farrace stresses that the challenges here are not primarily in the technical area. “The technology exists, and it works. What’s needed is the right framework,” he says. Legislation and regulations in Switzerland are still too conservative. He’s not deterred by this. “We want our input to make an active contribution to the energy transition.” To achieve this goal, the V2X pioneer is happy to accept interviews at temperatures over 30 Celsius.

The “V2X Suisse” project

The “V2X Suisse” project was launched in Bern on 6 September 2022. Since then, the project participants have been investigating, as a first step, how electric cars can be used as storage devices in order to close gaps in the power supply and improve grid stability. Seven companies are behind the project, with Mobility taking the lead and stationing 50 Honda e cars at 40 of its locations throughout Switzerland. These electric vehicles will feed electricity from their batteries back into the grid when they’re not being driven.

In addition to Mobility, the following companies are involved in the project: car manufacturer Honda, software developer sun2wheel, charge station developer EVTEC and aggregator tiko, with scientific support provided by novatlantis in collaboration with the ETH Federal Institute of Technology. The project is supported by the Swiss Federal Office of Energy’s pilot and demonstration programme.

Images Copyright: Patrick Besch

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