National Grid Electricity System Operator (ESO) put two coal power stations in the UK on stand-by to help manage demand, in a winter of low wind and solar generation combined with freezing temperatures1. The account of that measure comes from Cenex, writing on 14 December 20221.
Cenex describes the period as one in which the threat of blackouts loomed "in the rarest of circumstances", and says other measures were implemented alongside the coal stand-by, including discounted bills for customers to shift electricity usage to outside peak hours1. The ESO's own announcement of the stand-by is not carried in the available material, and no dates for the stand-by period, no capacity figures for the two stations and no statement of how long they were held ready have been reported1.
The same account sets out what electric vehicle batteries could contribute. Chris Cox, Head of Energy Systems and Infrastructure at Cenex, calculated that if all existing EVs could perform vehicle-to-grid (V2G) charging, there is potentially 3.7 GW of flexible power in EVs, which could be used to reduce national demand by around 8%1.
"Just imagine what that would mean for everyone's energy bills this winter!"
The EV-elocity project, led by Cenex until it finished earlier this year, deployed V2G chargers at a range of locations across England as part of large-scale trials1. It found that, by carefully managing charging and discharging in some situations, up to 450 kg of emitted carbon dioxide or £400 could be saved per vehicle each year, a figure Cenex notes has increased significantly with current electricity prices1. Cenex also identified resilience, providing power in periods of outages, as one of the five key value propositions of V2G following research in 20201.
The stated barrier is timing. V2G technology is still in its early phases of development and is only likely to achieve commercial readiness and mass rollout in the UK between 2030 and 2035, due largely to EV manufacturers not supporting V2G for existing models1.
| Measure described | Figure given |
|---|---|
| Flexible power in EVs if all existing EVs could perform V2G | 3.7 GW1 |
| Potential reduction in national demand | around 8%1 |
| Annual saving per vehicle from managed charging and discharging | up to 450 kg CO2 or £4001 |
| Expected UK commercial readiness and mass rollout of V2G | between 2030 and 20351 |
Why it matters for households
The stand-by of coal units is a signal about the margin between what the grid can generate and what homes draw at peak. The UK electricity generation mix shifts with weather, and a still, cold spell reduces both wind output and solar output at the same time as heating demand rises, which is the pattern described here1. That combination is the subject of the winter gap between generation and demand.
For a household, the practical effect of a tight system appears in how peak hours are priced and in appeals to move usage, such as the discounted bills for shifting electricity outside peak hours described in the account1. A home that can store or shift its own electricity, whether through a battery, a diverter or a vehicle, is less exposed to those peak periods. The V2G figures above describe that idea at national scale, but the same account puts mass rollout of V2G between 2030 and 2035, so the capability is not generally available to households now1. Whether a behind-the-meter system can export surplus electricity depends on the connection and the tariff, and the sources here do not set out the rules.
What happens next
Cenex says those involved in the trials and demonstrations will continue to validate the benefits so that manufacturers and users can have full confidence in the technology and its impacts on the grid and society1. No further stand-by measures, end dates or subsequent ESO actions are reported in the available material1.
Sources1 cited
- V2G: mitigating future winter blackouts, cenex.co.uk