The days when electric vehicles (EVs) could be dismissed as a minor phenomenon on our roads are definitely over. In the first quarter of 2022 alone, more than 2 million EVs were sold globally, an increase by 75% compared to the same period in 2021. According to the International Energy Agency, it is projected that by 2030, more than every third new car will be electric.
A strong driver for this growth is governmental ambition to reduce carbon emissions and boost EV sales: in 2021, nearly 30 USD bn were spent by governments on subsidies and incentives for low-emission vehicles. Encouraged by this push towards greener mobility, more and more people are switching from traditional combustion-engine vehicles to electric vehicles.
With the term electric vehicles, one normally refers to all cars that are either fully or partially powered by electricity, although there can be huge differences among the different types of EVs. While some are fully powered by an electric battery and are therefore zero-emission vehicles, other models only use their electric motor to assist the fuel-powered engine. With the rapid technological developments in this field and the increasing number of EV models on the market, it can be difficult to keep up with the main types of EVs found on our roads today.
Here's an overview of the main types of EVs and how they work:
HEVs are the first step towards low-emission driving. They feature a moderately sized internal combustion engine (ICE), combined with an electric motor and a small battery. In a typical HEV, the main role of the electric motor is to assist the ICE during driving tasks, such as start-up or acceleration, and to achieve better fuel economy. Unlike other EVs, HEVs can't be charged up, but they are refuelled just like a normal ICE vehicle. The power for the battery is generated through regenerative braking.
PHEVs are very similar to HEVs but with different proportions of the main components: they have a smaller combustion engine and a larger battery, which means the vehicle can cover longer distances using electric power. When driving a PHEV in all-electric mode, all the car's energy is generated by the electric motor and the battery, and no tailpipe emissions are released. Once the battery is depleted, the combustion engine kicks in and the car is powered like a conventional fuel vehicle. In addition to energy recovery when braking, the battery of a PHEV can also be charged by plugging it into a home charger or public charging point.
Owing to the fairly small battery, the electric-only range of most PHEVs is currently limited to 40–80km. But in many cases, this may already be sufficient for everyday usage. By activating hybrid mode, which uses both fuel and electricity, many PHEVs can reach a total range of over 800km.
Lastly, there are BEVs, also known as all-electric vehicles or zero-emission vehicles, which rely solely on electricity. BEVs don't have a combustion engine, as they're fully powered by an electric motor that draws current from the onboard battery. The battery pack is charged by plugging it into the electrical grid. With a larger battery in place, the driving range of modern BEVs can easily reach 200–300km on a single charge and even reach over 600km for some models. As charging a BEV with a near-empty battery can take several hours, long-distance travelling may require additional planning, especially in terms of when and where to charge. As all-electric vehicles have fewer and simpler integrated components, using and maintaining such vehicles are easier and often cheaper compared to HEVs or PHEVs.
A special type of BEV is known as a range-extended/extended-range electric vehicle (REEV or EREV). In this case, the car is still solely powered by the electric motor, but a built-in fuel engine can be used to generate additional electricity. When the battery is depleted, the engine kicks in and charges the battery.
Like BEVs, FCEVs are all-electric vehicles, but instead of storing energy in an electric battery, FCEVs come with a hydrogen fuel cell that is refilled at dedicated hydrogen stations. The fuel cell uses hydrogen in a chemical reaction to produce electricity for the electric motor. Advantages of FCEVs include their high efficiency and flexible operating range. However, a lack of hydrogen-refuelling infrastructure, the high energy demand required, and the related cost of hydrogen production and transport are blockers to wider commercialisation.
With so many different types of EVs to choose from, selecting the right one is not always an easy task. Only by understanding the differences between the available technologies can a person pick the EV that best fits the individual needs. The easy access to charging infrastructure is equally important to consider, be it at home or via public charging spots. Running cost may also vary significantly among EV types that are primarily recharged or refuelled. Until recently, the lower cost of energy compared to constantly rising petrol prices made BEVs and PHEVs a particularly attractive choice. With the recent surge in energy costs however, the price difference between petrol and electricity has shrunk again. Nevertheless, direct comparison of running cost shows that to depend on electricity rather than on petrol is still more cost-efficient – and with that not only beneficial for the environment, but also for the bank balance.