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Is the grid ready for electric cars?

Sustainability By Graham Thomson, Associate Director, Building Services – 11 November 2021

Painted flooring of a car parking space indicating a white electric vehicle on a green background


Graham sat in a pale shirt with grey suit jacket and brown tie smiling at the camera.

Graham Thomson

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With the UK Government announcing the ban on new internal combustion engine (ICE) car sales from 2030 (originally 2040) which is quickly followed up with hybrid cars in 2035, where does this leave the consumer and how will this impact the UK national grid as we know it?

This may sound like progress, but consumers will still be able to buy and sell ICE cars with no ban date set yet. Given the average age of a car in the UK is currently 8 years, meaning that millions of ICE cars will still be on the road, way past 2030/2035.

There are approximately 40 million drivers running petrol and diesel ICE cars which, according to the UK government, are producing upward of 18% (28% when including goods transportation) of the country’s CO2 emissions. This percentage is large, and we could reduce it to near zero over the coming decades with the ban on ICE car sales and other users (agricultural / transportation, etc) and introducing Electric Vehicles (EVs).

Car chargers range from the domestic end of the market, i.e., 3.6kW 230V plug-in at your house up to 350kW ultra-fast chargers, typically found on motorway rest stations.

The varying range of chargers provides for a large scope of charging offered to consumers to re-energise depleted batteries over a period of time. The domestic 3.6 / 7.2kW chargers can provide 15 / 30 miles with an hour’s charge. Compare this with an ICE car which can carry fuel providing a range of 350 – 450miles therefore an electric car will take approximately 23 / 15 hours to charge from flat to 100% using the 3.6 / 7.2kW chargers.

The fast / ultra-chargers, which charge cars using either alternating/direct current can charge cars within 30mintues providing 240miles of range.

These charging units will not be presented to the network as a continual load although the domestic type would typically be used between 6 pm – 8 am and the fast / ultra-chargers during periods through the day (typically at rush hour). This imbalance of charging times will present difficulties to the UK national grid where they will also have to contend with the domestic switch on. Example, homeowners returning home in the evening and switching on kitchen equipment as well as plugging into their domestic car charger.

With the demise of coal-fired power stations, limited nuclear power stations and the operational reduction in gas-fired turbine power stations, renewable energy will be key to keeping the lights on and providing power for the inevitable increase in demand from EVs. Analysis has been carried out which demonstrates that the current demand across the system on the UK national grid (approximately 300 terawatts) is set to increase 400 terawatts. Of this, the network can accommodate even at this time without major re-enforcement works.

As we move from ICE to EV’s (approximately 1 in 7 new cars sold between 2019 – 2020 were EV’s) we will start to develop respect for energy and how we consume it as we drive to work or the shops. As chargers are getting “smart”, they will drive users to charge vehicles out with peak times, therefore, removing the peak loading on the UK national grid network.

As we embrace a transportation revolution, there are other sources out there being developed by the large car manufactures where hydrogen may make an introduction into the field. Although substantial networks would need to be set up and configured to allow this technology to be developed.