Vehicle-to-grid EVs are a double win for owners and the environment

Dr Jon Hiscock, CEO of grid voltage control specialist Fundamentals, explains how the latest EVs with bidirectional charging are great news for savvy owners and the environment.

Starting with the Renault 5 E-Tech, winner of the European Car of the Year Awards 2025, all new EVs from the French manufacturer will feature bidirectional vehicle-to-grid (V2G) charging.

Renault is also pushing its Powerbox bidirectional charging station from subsidiary Mobilize – a domestic EV wall-box with its own smart tariff supply contract.

Growing numbers of new EVs have V2G capabilities, but Renault’s offer of a complete car-plus-charger package is a potential game-changer. Because the Renault 5 is more than just a nice new EV. It is an example of a flexible energy storage system on wheels, with enormous potential to save canny users a lot of money, while cutting carbon emissions significantly.

Buy one, get one free?

The entry level Renault 5 costs £23,000 (around £250 pcm to lease), with a 40kWh battery. Good value for a ‘conventional’ EV. But amazing value as a home energy storage system on wheels.

Consumers seeking to cut their energy costs by investing in domestic battery storage would be hard pressed to find a 40kWh package, fully installed with all its control systems, for £23,000.

So Renault is effectively offering customers an award-winning EV at a highly competitive price, with a powerful home battery storage system as a free bonus.

Or you could see it as a bargain battery storage system, with a super-desirable car thrown in for free.

Either way, we believe V2G EVs from Renault and others will prove increasingly attractive to the growing number of customers who are using home battery storage, together with smart tariffs, to trade energy with the grid and cut their electricity bills.

Saving prosumers money

The prosumer market is already well established. These are the canny customers who have solar panels, battery storage, EVs and heat pumps – and use flexible tariffs from the likes of Octopus to consume and store energy when it is cheap. Then, when prices are high, they either use their stored energy or sell it back to the grid.

A 40kWh (or bigger) battery-on-wheels is a lot of energy storage. Most daily EV drivers will not need the full 160-180 mile range it provides for commuting, school runs and shopping. So there is plenty of surplus energy to play with.

Even without hooking solar panels into their home energy systems, consumers can save serious money by using stored energy to capitalise on the latest time-of-use tariffs.

Charge the EV/battery in the dead of night, when electricity is cheap – or even free. Use some of it for morning motoring and home energy needs, then some more in the evening.

And when demand peaks, suppliers will pay handsomely to take a few kWh from an EV/battery, then automatically replace it with cheap energy later.

Cutting industry costs

V2G-equipped EVs are also good news for the electricity industry – and the environment.

The transition to renewable power generation requires massive amounts of energy storage, to balance supply and demand when there is little or no power from sun or wind. And to deal with dramatic fluctuations in demand during the day, especially early evening peaks.

When energy from renewable sources and stored energy is insufficient to meet demand, fossil-fuelled generation kicks in. Not just gas, but during high peaks, from a variety of carbon-intensive backup generators.

However, when renewable energy exceeds demand and the excess cannot be stored, it is simply ‘dumped’.

Grid-connected V2G EVs, together with standalone domestic batteries, would improve the situation by reducing the amount of new transmission and distribution infrastructure required (the pylons, cables and substations needed to move energy from large generation and storage facilities to consumers) and also reducing the amount of energy waste.

Reducing carbon emissions

Mass adoption of V2G EVs would create a network of community-based energy stores, capable of interacting with the grid: balancing supply and demand, with much lower reliance on carbon-producing reserve generation.

They would also help balance out the growing problem of surges and drops in voltages in networks – the field in which we are deeply involved, as specialists in grid voltage control solutions – caused by increasing numbers of low-carbon technology connections (EVs, heat pumps, solar PV etc.) and the corresponding dynamic power flows.

V2G-capable EVs will not solve all the problems of decarbonising our energy systems. But we believe they have enormous potential to save money for consumers and the electricity industry, whilst lowering emissions overall. A resounding win for everyone.