Aside from decarbonising the transport sector, electric vehicles (EVs) are also starting to play an important role in balancing the UK’s power grid.
The context: Grid operators must constantly maintain a steady balance between electricity demand and supply to keep the entire system stable.
In many markets, gas-fired power plants are the primary flexibility tool, as they can ramp up and down their output quickly. However, newer flexibility services are challenging the status quo.
EVs, for instance, can feed power back into the grid during peak times to help meet surges in demand. On the other hand, when there’s excess supply — typically during the middle of the day or late at night — incentivising EV charging is a handy way to bring things back into balance.
The latest: In early February, Great Britain’s electricity system operator (ESO) announced that it would allow up to 300MW of aggregated assets — including EV chargers and electric heating systems — into its flexibility toolkit. The ESO will be able to turn to those distributed assets when it needs a demand or supply boost.
“Opening up to flexible assets of this kind is vital in achieving our ambition of 100% zero-carbon operation of the electricity network by 2035 and delivering the clean, green energy system of the future,” the ESO said in a statement.
In its roadmap towards the middle of the century, the operator sees vehicle-to-grid assets contributing up to 20GW of demand-side response capabilities after the 2030s.
And smart EV charging could contribute to a 60% reduction in peak demand in 2050, its projections show.
While there’s a long way to go to reach that point, things are starting to move fast.
A study by BloombergNEF found that EVs and batteries now offer the system operator more flexibility capacity than gas plants do, though they aren’t yet called upon as much.
That could change in the years ahead.
In mid-February, electricity retailer Octopus Energy launched the UK’s first mass-market vehicle-to-grid tariff, which “guarantees free charging for drivers” at times when electricity demand (and prices) is low.
An average electric car driver could save more than £850 a year in charging costs on this plan, Octopus says.
The idea is that EVs will automatically charge during off-peak times, and then export back into the grid when it needs it most.
While only a limited number of EV models have vehicle-to-grid capabilities for now, manufacturers promise to change that.
“We recently moved past a million EVs on UK roads – a major milestone – but their true power for storing energy remains untapped,” said Alex Schoch, head of flexibility at Octopus Energy. “Once we reach 10 million electric cars on the road, we’ll have enough storage to power the entirety of Great Britain during peak times… EVs are going to be a major lever in our future flexible, green grid.”
