How sustainable is your commercial EV fleet?

EVs can be cleaner than their petrol or diesel counterparts - emitting no particulates, thanks to the lack of an internal combustion engine (ICE) - but there are lifecycle emissions to consider when making the switch.

These lifecycle emissions come from the production of EV batteries, and from the electricity which powers them.

Understanding battery-related emissions

Manufacturing each kWh of battery capacity creates a similar amount of carbon as burning through a full tank of petrol. Depending on make, model and size, EV battery capacity ranges from 30-100 kWh. Different businesses will have different fleet requirements, and so may need different sized vehicles.

For larger batteries or top-end models, this rises significantly, and can equal the carbon emissions of three round-the-world flights. More CO2 is emitted in building the battery for a premium EV model than from recharging it over a 15-year lifetime.

However, the most efficient EV models could need just two to three years of driving to save the amount of carbon emitted in producing their batteries. Smaller EVs with modest battery sizes are better for the environment, whereas the largest luxury EV models could need three times longer to pay back their carbon cost.

The most common batteries used with EVs are lithium, much like you’d find in your laptop or smart phone. The size of the battery directly impacts the range achievable from a full charge. With 35kWh batteries being used for cars that are more suited to short or in-city commutes. Batteries have a long lifecycle, which helps to offset any (perceived) environmental damage. Batteries can also be used for other applications when they're no longer suitable for use in an electric vehicle.

We foresee the lifespan of an EV battery to go beyond its usefulness for an in-car battery and be used to store energy for domestic use for a further 10-15 years. This has already been seen in studies, including a project in Australia.

Fuel for thought

EVs don’t emit any CO2 while driving, but the electricity that powers them can produce greenhouse gas (GHG) when it’s generated.

The UK’s power system has changed dramatically in recent years, with carbon emissions falling significantly as a result. One kWh of electricity produced in 2019 contained 204 grams of CO2, less than the carbon released from burning one kWh of petrol. And because EVs have more efficient motors, they can drive further on 1 kWh than a petrol or diesel car could.

When charged with a typical energy mix, EVs across Britain emit around a quarter of the CO2 of ICE vehicles. Add in the emissions from battery production, and this brings it up to around half of the CO2 emissions of a petrol or diesel car.

As more renewable generation comes on stream and the electricity system decarbonises further, this could drop to as low as 10%.

Renewable generation creates electricity that’s zero carbon at the point of emission. Suppliers that provide renewable electricity can accurately state that every kWh of electricity contains 0 grams of CO2. An EV fleet charged with renewable source electricity can reduce the carbon emissions they’re responsible for. However, as long as the UK still uses non-renewable fuel sources, there’s still carbon in the total lifecycle and the grid mix.

The impact of size and shape

Smaller EVs are popular, and typically have a 30-45kWh battery. This limits their emissions to around 33g/km, or lifetime emissions to around 60g/km. With the expected changes to the national energy mix over the coming years, this will continue to fall to around one-third of an ICE vehicle.

Larger EVs - such as luxury saloons and SUV models, including Tesla models - need more energy to move. This means higher emissions than smaller models, at an average of 44-54 g/km. This is still just a quarter of the emissions from a comparable conventional car.

The lifetime emissions of these larger EVs are pushed up by their larger batteries, however. The 90-100 kWh batteries offer greater driving range, but are responsible for more CO2 emissions over its lifetime.

Electric vans are increasingly popular, with over 8,000 on the road in 2019. Their performance is comparable to small hatchbacks, emitting around a quarter of the CO2 as their ICE counterparts at around 40 g/km.

With their 30–40 kWh battery pack included, this rises to just below half the CO2.

These projections are based on forecasts from 2019. To find out more about the figures we’ve used, please see the link at the end of this article.

When considering making the switch to EV, it’s key to calculate your fleet’s operational requirements. The number of vehicles, and the type you choose, could impact the total carbon output of your fleet.

Paying back lifetime emissions

A 2021 study from the International Council on Clean Transportation (ICCT) revealed that the lifetime emissions of EVs are lower than ICEs, too.

The study compared the lifetime emissions from mid-sized EVs from India, China, the US and Europe. EVs in Europe are estimated to have a carbon footprint which is 66-69% lower than ICEs; in the US, it’s estimated at 60-68%.

In China and India, both of which use more coal for energy generation, EVs are estimated to have a smaller footprint by 37-45%, and in India it’s 19-34%.

A typical ICE vehicle covering around 7,500 miles per year produces 1.5 tonnes of CO2. An electric vehicle doing the same mileage would take 4 years to produce this amount. Fully electric vehicles, and plug-in hybrids driven in electric mode, produce no harmful tailpipe emissions. That means no carbon dioxide (CO2), no nitrogen oxide (NOx), and no particulates (atmospheric aerosol particles).

Conventional vehicles can’t reduce emissions over their lifetimes, as petrol and diesel fuels can’t become carbon-free. As the carbon content of Britain’s electricity continues falling, an electric vehicle bought now will emit half as much CO2 in 2025 as it does today.

With Britain’s grid electricity of around 205 g/kWh, smaller electric cars and vans will take between two and four years to repay the amount of CO2 than was emitted in making their batteries. For the larger luxury models, it’ll be closer to five to six years.

As the electricity mix gets cleaner, this payback time will continue to fall, and EVs will become more sustainable over time. In 2020, for example, the average carbon intensity of grid electricity was 172g/kWh - which shows the speed at which decarbonisation can happen.

While the debate around emissions for ICE vs EV isn’t black and white, it’s clear in the science that EVs are cleaner - and more sustainable - for businesses today. This argument will only become stronger as technologies develop, and the grid decarbonises.

The data used in this article comes from a 2019 Electric Insights report by Dr Iain Staffel. You can read the report by clicking the button below.