Hand-in-hand: How the UK’s electric vehicle revolution can strengthen the power grid

Ambitious policy on transport will help the UK toward its clean power goals

By Jonny Marshall

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This weekend brought another glimmer of hope that campaigners have been waiting for: another strong signal that, from 2030, only electric cars and vans will be sold in the UK, albeit with a five-year reprieve for hybrids.

The economic, health and environmental benefits of this decision are now well-established, with few serious arguments against. One debate which lingers on, despite a slew of evidence that shows it isn’t a risk, is the effects that plugging millions of electric cars into our power grid will have on National Grid’s ability to keep the lights on.

But rather than being a problem, the events of just last week highlight the potential for a speedy, widespread EV rollout and a surge in clean power generation to go hand-in-hand.

Grid warning

Despite numerous warnings, Britain's electricity system is one of the world's most reliable. Image: National Grid
Despite numerous warnings, Britain's electricity system is one of the world's most reliable. Image: National Grid

Last week saw National Grid issue Electricity Margin Notices on two consecutive days, as low wind output coincided with a host of outages at nuclear, gas and biomass power stations, and as grid constraints saw more than 1 GW of power that could have been produced at wind farms unable to be delivered.

These notices are a signal to the market that the buffers National Grid prefers to operate with were smaller than normal, in a bid to incentivise additional generation to come on stream. Several years ago they were a much more common occurrence, but last weeks’ were the first since 2016.

At their highest, these warnings were of a 740 MW shortfall for two hours on Wednesday (later revised down to 477 MW) and a 316 MW gap for three hours on Thursday afternoon, corresponding to 1-2% of total demand.

Crucially, both warnings were ultimately cancelled as the market responded to deliver additional capacity.

Earlier in the week, though, as the UK was buffeted first by Storm Aidan and then by the remnants of Hurricane Zeta, the grid closed in on being 50% wind-powered. This would have been higher still were our increasingly outdated power grid more able to transport power from where it is generated to where it is consumed.

Far from exacerbating these issues, the inherent ability of EVs in all corners of the country to step in and balance the system would make life easier for the grid operator.

Plugging in millions of mobile batteries would see excess power mopped up and shortfalls easily filled. This will smooth the way for more clean power sources to come online – both variable renewables and inflexible nuclear – underpinning the nations net zero transition.

On ambitious scenarios, there could be over 11m electric vehicles on UK roads by 2030 (or 36 million by 2040), compared with just 375,000 plug-in-cars today.

Electrification of transport on this scale, alongside widespread uptake of smart charging, brings with it huge opportunities to fundamentally reshape Britain’s power system.

A vital step in achieving these higher figures is an ambitious signal to the market – a phase-out date one of the best – to kick start development of new, clean models.

Powering up

The UK-made Nissan Leaf is Britain's most popular electric car. Image: Nissan

An entry level Nissan Leaf – the UK’s most popular electric vehicle – comes with a 40 kWh battery, while nascent vehicle-to-grid technology brings an export power output of 6 kW.

Therefore, even had Wednesday’s 740 MW shortfall been actually come to pass, it could have easily been sated by the output of just 120,000 cars plugged in on Britain’s driveways; less than a third of the number of plug-in vehicles currently on the road.

The combined storage capacity of these cars alone – just 1% of the number that could be on the road in 2030 – is more than double the highest projected energy gap for Wednesday and Thursday combined.

Even now, both capacity and energy gaps could have been filled and cars left with enough stored power to pop to the shops if needed.

Clearly, current 2020 technology (small family cars and slow trickle chargers at that) is more than capable of stepping up to keep the lights on. As the 2030 phase-out date results in ever-more electric cars, and Britain’s world-leading smart power revolution continues, these numbers will start to look miniscule.

Held back

So why didn’t EVs jump into export mode? Why did National Grid issue these warnings, and why were coal power stations forced into life?

The simple answer is, regulation.

British companies are already able to package up hundreds of thousands of batteries, whether in cars, homes or businesses – along with industrial equipment and small peaking generators – into virtual power stations that can ‘fire up’ when needed.

However, the rules that underpin Britain’s energy markets mean these assets are not on equal footing with old-fashioned power stations, such as those that run on gas and coal. Without access to the same markets, and on the same terms as incumbent generators, this immense potential is not being fulfilled.

On top of this, slow progress on making the power system smarter and more dynamic means that tariffs that enable EV owners to cash in on selling power back to the grid are largely the preserve of early adopters.

Fortunately, though, the opportunity to change these is nearly upon us. The imminent Energy White Paper should lock in an overall strategy towards a net zero energy system, one with flexibility at its heart.

With regulations on how we shape and pay for power grids up in the air, there is scope for the system to change to one with an overall more competitive space for emissions reduction - EV batteries in the same market as gas plants, for example - and be focused on emissions reductions rather than profits, while more holistic thinking around renewables infrastructure should see Britain making the most of our island’s natural assets.

So, rather than sowing seeds of doubt over the lights staying on, we should be noting how we can make the most of ambitious policymaking on transport to go hand-in-hand with that in the electricity sector, locking in the clean and cheap energy needed to underpin the UK’s net zero revolution.