Batteries on wheels and smart charging

Batteries on wheels and smart charging - National Grid ESO’s Marcus Stewart explains the road ahead for electric vehicles and the electricity system

I own an electric vehicle. I’m lucky enough to be able to have a charge point at home and an EV works for me and my lifestyle. More and more people are making the same choice and finding an EV works for them too. In 2017, the UK Government’s announced that sales of diesel and petrol cars would stop in 2040 and National Grid ESO’s 2019 Future Energy Scenarios predict 35 million more on GB’s roads by 2050.

For the last 8 years I have worked at National Grid planning for the future, analysing demand for electricity and predicting trends, making sure the industry is ready for the changes ahead. Throughout that time our position on electric vehicles has become clear – they can have a positive role and help decarbonise both transport and electricity supply for Great Britain. That’s why we’re pleased to see today’s report from the Electric Vehicle Energy Taskforce, and their recommendations for government and industry to enable the EV transition – including prioritizing smart charging.

What is smart charging and why is it important?

As the numbers of EVs increase, their peak time electricity demand is one of the challenges that will need to be met. But in fact, this is where better consumer engagement and advances in technology both have a part to play.

Smart charging is using incentives to encourage people to charge outside of peak times, either through simple peak and off-peak electricity tariffs like Economy 7, or incentivising when there is more low carbon electricity available and ‘normal’ demand is low. There are examples of this happening already, at the end of last year windy conditions saw consumers being paid to use excess wind powered electricity, but it’s something we will need more of in future.

Another smart use of electric vehicles is turning their batteries into storage for excess electricity. As more renewable generation, such as wind and solar comes online, in periods of low demand for electricity there is the potential for oversupply - our modelling shows that excess electricity could rise to around 6% of total annual output after 2040. Storing it in EV batteries means it could then be supplied back to the grid peak times to smooth demand, this is known as Vehicle to Grid. We estimate that, in 2050, vehicle to grid – effectively “batteries on wheels” - could offset as much as 85% of the residual EV demand that remains in peak periods (after smart charging behaviour has shifted the majority of EV demand outside of peak hours1).

Working together

Smart charging is just one of the recommendations made in the EV Energy Taskforce report and clearly there is a lot of work to be done - but it’s heartening to see key organisations across energy, infrastructure and transport all taking a coordinated approach. A harmonised introduction of smart charging means that the transition to EVs can bring low cost clean energy to motorists and all consumers, while helping to strengthen the electricity grid too.

1. 2019 Future Energy Scenarios, p87,