The system allied electric car

Other than being an energetic leech, it gains electrons while giving nothing back. With the overall tests currently under way, the electric car will be an essential element for the balance and security of the new energy systems. Why not - and it's a sensible question - transform what is already a powerful “battery on wheels” into an integral part in a bidirectional energy exchange, for use both in our own homes but also, and most of all, on the big production and distribution grid? Why not use the “machine stops” not only to recharge but also to contribute to the balance and stability of the electrical system, in a continuous give-and-take framework governed through computer science and artificial intelligence?

The new electricity systems’ strategic axis is clear: produce electricity whenever is most convenient, store it, and release it whenever is most needed. Once upon a time there were hydroelectric basins, which will still have a long life ahead. But in order to achieve critical mass and take electrical systems into modern times, the winning card has large battery storage systems written on it. Also, why not, the one in our cars.

We study, test, and make the first working agreements. Last September, Terna’s CEO and General Manager Luigi Ferraris and FCA’s Chief Operating Officer for EMEA Pietro Gorlier signed a Memorandum of Understanding in Turin for joint testing of sustainable mobility service technologies, such as Vehicle to Grid (V2G), the solution which allows electric vehicles to connect to the grid via “smart” charging infrastructure. The E-mobility Lab will be set up at Terna's offices in Turin to develop technological solutions, and a feasibility study will be launched for an experimental demonstration fleet of electric vehicles connected to the grid via V2G infrastructure in an area of the FCA industrial complex at Mirafiori.

The magic formula. So what is the correct recipe for our batteries on wheels? You have those who think of a widespread system of smart recharging stations scattered across the Italian territories, in the cities and not only in houses, but on the streets and not only in the car parks in shopping centres. You also have those who are, like the Chairman of ENEA Federico Testa, looking for a more rational solution with faster implementation time, perhaps to be combined with that of the widespread stations: integrate the current filling stations (if operators and oil companies allow) with large battery storage systems, which in turn recharge the electric vehicle batteries. And it’s these large resident batteries that will act as the lung in the local, regional or even national distribution generation networks. But what are the technologies and practical solutions behind this scenario? The RSE, a public research company in the electrical energy sector which specialises in “Vehicle to Grid”, is here to help us scrutinize its characteristics and potential.

The “Vehicle to Grid” (V2G) and “Vehicle to Home” (V2H) exchange systems are as rational as we can imagine our energy future to be. The RSE argues that this is the best way to use an electric car to mutual benefit, when it would normally spend numerous hours of its day parked, either on a street or in a garage and in many cases connected to a give-take recharging station, and that it involves “maximum savings for the end consumer” based on two factors: direct payment for this contribution and savings resulting from the final prices mitigated by an efficient network.

This is how "exchange" works. “A recharging system like this,” the RSE explains, “consists of a bidirectional power inverter which connects to the vehicle through the high-voltage battery’s positive and negative leads (300-500 Volts) and to the grid at low voltage”. Smart grids governed via computers and system command centres (the operator, in the case of the public network, or the control unit, if connected with the operator, in the case of direct energy exchange systems connected with our homes) the bidirectional inverter or withdrawal to recharge or deliver energy as a shared stations “with a maximum band of around 10 kW, to send it to the grid and match generators” as is the case for photovoltaic systems, for example.

Is there a risk that the car will “run out” when we need it most? No. “The management software is designed to provide the expected service (according to grid operator command for V2G, according to maximum utility for V2H users), but with the constraint of fully charging the battery within a time specified by the user.

Everyone’s affair. How to technically govern the system is a challenge for engineers. How to best distribute the economic benefits is a challenge that involves various actors: managers, institutions, governors, regulators. Also because these solutions enable obvious synergies with all those generation plants, large and small, even those that private individuals own or intend to implement, starting from the photovoltaic, which already has its grid exchange mechanisms.

So we look abroad, where, as the RSE notes, “the framework allows and remunerates the loading and unloading operations in a sustainable through the V2G technologies”. The first European trial “took place in Denmark, mostly because in this country the barriers to involvement in this service are some of the lowest in Europe” and where a group of 30 cars managed through one “aggregator” operator is enough “to access the provision of frequency regulation and allow vehicle owners who leave their car stationary from 18:00 to 08:00 the next day to earn almost € 1,500 per year, without sacrificing the security of finding a fully-charged car each morning.

For us, too, analysts draw significant profit margins. In cases where the benefits in terms of synergies with the electricity system could be more substantial, such as public transport or company fleets, the recharging costs could be more than halved. But even in the most fragmented systems, such as those set up around a domestic recharging system, the cost advantage could reach 40% during the hours when the electrical system would get the greatest benefits (for example in the 3 hours between 18:00 and 21:00). It's too tempting a challenge not to put it all out there.