EV “batteries on wheels” could save hundreds of billions in grid costs by 2040, report finds

A new study from Europe’s clean transport & energy group Transport & Environment (T&E) has found that using the batteries in electric vehicles (EVs) to store energy and feed back into the grid could save hundreds of billions of dollars.

The promise of bidirectional charging – which allows vehicle to grid (V2G) and Vehicle to Home (V2H) technology – has become an increasingly attractive byproduct of the transition to EVs, creating the potential for a fleet of what T&E describes as “batteries on wheels” to store excess electricity when it is cheap and in surplus, and sending it back to the grid when demand is high.

According to the report, bidirectional charging and V2G could save the European Union’s energy systems €22 billion annually by 2040, somewhere around $A35 billion.

This would be equivalent to an 8 per cent reduction on the cost of building and running the EU’s energy system, resulting in total savings of as much as €175.45 billion (around $A290 billion).

The economic savings would be generated by helping to store excess renewable energy, avoiding the need for stationary storage by up to 92 per cent and allowing European grids to integrate up to 40 per cent more solar PV capacity, or as much as 430GW by 2040.

Moreover, by storing excess renewable electricity that would otherwise be lost, the report predicts that Europe’s EV fleet could contribute up to 9 per cent of the EU’s annual power needs by 2040, making EVs the fourth largest electricity “supplier” in the EU.

“Electric vehicles have put road transport on the path to decarbonisation, but they have more economic benefits yet to be realised,” said Fabian Sperka, vehicles policy manager at T&E.

“Bidirectional charging will offer batteries on wheels for free, reducing the need to build energy storage for excess wind and solar power.”

The report also predicts that allowing EVs to draw down excess electricity when it is cheap or from home solar panels, bidirectional charging could save EV drivers up to 52 per cent on annual electricity bills, equating to reductions of up to €780 a year.

However, this is at the high end of potential savings, which range between 4 per cent to 52 per cent, with savings ranging from €31 to €780 per year.

It is also expected that bidirectional charging can help to extend the life of EV batteries by up to 9 per cent compared to standard EV charging practices, as the car is maintained in an optimal state of charge.

These benefits could be achieved virtually for free, according to the report’s authors, with the average €100 greater expense of a bidirectional homecharger over a traditional wallbox being offset by reduced electricity bills within a few months.

However, if the EU is to achieve these benefits from bidirectional charging, a regulatory framework is needed so as to ensure interoperability between all EVs and chargers.

“V2G can only take off if we ensure all EVs can work with all chargers,” said Fabian Sperka.

“Lawmakers can unlock the potential of this technology by deciding the EU standards for bidirectional charging. That will be a win for consumers, the environment and progress towards the EU’s climate and energy goals.”