The UK government is aiming for all new car and van sales to be electric in 2035. Can the electrical grid cope, and how clean will that energy be?
What is the carbon intensity of the UK grid?
Electric vehicles are only as clean as the energy they use, and UK grid electricity is decarbonising quickly. National Grid ESO, which is responsible for moving electricity around the country, is targeting a 100% zero-carbon supply by 2025 – and that includes capacity for meeting peak demand with a growing share of renewable sources, electric vehicles registered today will become gradually less carbon-intensive over the course of a three or four-year lease.
Understanding UK grid carbon intensity
Average carbon emissions per kilowatt-hour (kWh) reached an all-time low of 181g/kWh in 2020 – a 65.8% reduction compared to 529g/km in 2013[2]. For a typical mid-size electric car returning 3.5 miles per kilowatt-hour, that would equate to 32g/km CO2 emissions in 2020, with only 1.6% of that energy produced from burning coal. But the UK grid carbon intensity can be much lower than that. In April 2021, the grid recorded a record low carbon intensity of 39g/kWh, equivalent to 6.9g/km for that same vehicle, including energy production and distribution. That’s significantly lower than the tank-to-wheel figure for a petrol or diesel car.
Can the UK grid support electric cars?
A common concern about electric vehicles is the effect of drivers returning home and charging early in the evening when demand is already at its highest. However, peak demand has fallen during the last 20 years. This offers some headroom for National Grid Group’s projected 10% increase if every UK household switched to an electric car. That’s in part because of smarter EV charging.
Foundations for a greener future
The groundwork is already being put in place. Grant funding for home and workplace chargers already requires units to be capable of exchanging usage data anonymously and adjusting charging rates to reduce demand spikes [5, 6]. Announced as part of Prime Minister Boris Johnson’s ‘Ten Point Plan for a Green Industrial Revolution’, the UK Government will also invest in facilities to store excess renewable energy and release it when demand is at its highest. This reduces the need for fossil fuels a backup, which is what happens today.
Smart technology
Electric vehicles are expected to play an active role in this ecosystem, reducing the need for additional generation capacity. By 2050, National Grid ESO predicts 80% of households will smart charge their electric vehicles, automatically pausing charging to stabilise demand. The report adds that 45% (5.5m cars and vans) could utilise ‘vehicle to grid’ (V2G) technology by the same date. This would enable them to supply energy from their batteries back to the grid when extra capacity is needed.
How can I minimise my electric vehicle’s carbon impact?
Small behaviour changes can make a big difference to your electric vehicle’s CO2 emissions and could save money too.
Here are some simple steps:
1. Get a Smart Meter
The UK Government is offering smart meter upgrades for every household in England, Scotland and Wales by 2025, and they’re an important component of a cleaner energy system. A smart meter provides a live display of energy consumption for users, while automating the billing process and generating data that can inform wider integration of renewables into the grid. Installation costs are included within your energy bills, and you can request upgrades here.
2. Watch the Grid
UK grid carbon intensity varies by region and the time of day, as increased demand relies on a larger share from non-renewable sources. To help consumers understand those fluctuations, National Grid ESO has a live calculator that tracks and predicts CO2 emissions and suggests the best times to plug in. It’s available as a free app for Apple and Google devices, and at carbonintensity.org.uk
3. Change Your Tariff
The lowest-carbon electricity can also cost less. Switching to a Dual Rate tariff introduces much cheaper unit costs (per kWh) for charging overnight when demand on the grid and CO2 emissions from generation are lowest. Several utility companies also offer specific tariffs for renewable energy.
4. Plan Your Charging
Most plug-in hybrid and electric vehicles have a feature that enables charging to be scheduled for off-peak tariffs or periods when grid carbon intensity is at its lowest. This could help mitigate demand spikes and reduce running costs for drivers too. Plan your charging when away from home by navigating the UK’s public charging networks.
