National Grid ESO - ENCC transparency roadmap - electric car on a road
EVs and electricity

We estimate that up to 37.4 million EVs will be on UK roads by 2050 – that’s a huge increase on today, where there are fewer than 1 million.  

Such numbers will see EVs playing an important role in transforming the electricity system, with things like smart charging, ‘vehicle to grid’ technology and charging behaviour key to helping bring down carbon emissions. 

Let’s take a look at how electrifying the way we get from A to B and beyond will help the UK on its journey to net zero 2050. 

Charging behaviour 

When, where and how consumers top-up their vehicles is vital. 

Our studies show that around 75% of owners charge at home, and as this is likely to remain the case for those who can, it raises the question of when consumers will plug-in.  

Will they plug in frequently and top-up charge (grazing)? Or will they plug-in less frequently and top up from close to empty (guzzle)? Plugging in more frequently could have flexibility benefits for the energy system. 

Flexibility will be essential to encourage consumers to change their consumption patterns through what is known as a Time of Use Tariff (ToUT). This will create a financial incentive for consumers to change their charging to a time when the rate is cheaper and electricity is greener. 

In the future, charging behaviour will change as many consumers will likely play little part in actively managing their charging and will rely on their supplier to do this for them. They will just plug their cars in when parked up and then drive off when they want to.  

In 2020 the road transport sector used over 400 TWh of energy in 2020, accounting for 30% of total energy demand in Great Britain and 23% of the UK’s greenhouse gas emissions. 

What is smart charging? 

Put simply smart charging is charging a vehicle within a time slot, usually overnight but not always, to avoid high demand periods on the system and taking energy when demand from other uses is lower -  similar to how economy 7 heating works.  Smart charging technology also helps consumers draw energy from the grid when there is surplus power, which is usually cleaner and cheaper, to help balance the grid. 

What is vehicle to grid (V2G)? 

Vehicle to grid is the next stage on from smart charging. The idea is that electric vehicle owners will have a smart charging point which can talk to our technology via their energy supplier. EV owners can then automatically charge their car batteries when there is extra renewable power available and offload electricity when there is too much.  

Combining smart charging and vehicle to grid technology means the EV owner simply sets a minimum charge for their battery (enough to get them to work and back, for example) and if the system requires a boost overnight, we can draw electricity from their battery – they will be paid for this of course! 

Once the peak in demand has been satisfied, the charge will be returned. 

This power sharing idea also has the possibility to be used commercially too. Like using electric cars parked at airports or a fleet of commercial vehicles which are normally parked overnight, to help manage the ups and downs of renewable electricity generation. 

In 2050, our latest Future Energy Scenarios (FES 2021) shows a total electricity demand for road transport in 2050 down to 153 TWh. One way to think of vehicle to grid charging (V2G) is that it acts as a mini battery, giving power back to grid in times of high demand. 

As more consumers start to own Battery Electric Vehicles (BEVs), smart charging and V2G uptake will help manage the rise in renewable energy on the electricity system. 

V2G will need to provide some incentives for the consumer to provide energy back to the grid. Watch our video on 'what is vehicle to grid technology' for more information. 

There are challenges too of course. Because not all vehicles are always connected to the system, the available storage capacity from EVs varies in a way that differs from traditional energy storage systems. 

And reaching net zero is about more than EVs. The biggest impact the consumer can have on the efficiency of the transport system is doing less miles in their cars, and instead choosing active or public transport.  

At the ESO, we believe policy makers can help enable consumers make these choices by considering things like cycle routes, public transport funding and vehicle taxation. See our Future Energy Scenarios (FES 2021) for more details