Energy efficiency, climate change, and sustainability ‒ our society is facing a number of major challenges, global as well as local. Our choices of vehicles and transportation solutions in general are often discussed in this context. The global challenges of the vehicle sector are mainly related to fuel consumption as this is directly linked to CO2 emissions. Politically oil dependency and resources contribute to the agenda. On a local and regional level, the challenges are more related to connectivity and emissions – the transportation of people and goods to, and in, our cities should be as smooth as possible. Noise is one type of emission greatly affecting life in the cities, triggering a desire for ‘silent’ vehicles (without, of course, reducing the safety of pedestrians). Different kinds of electric vehicles can clearly contribute to solve these issues and help us to reach a more sustainable future for our modes of transport.

There are mainly three kinds of electric vehicles: hybrids, all-electric, and plug-in hybrids. The all-electric vehicle relies solely on electricity and the other two utilise both electricity and an internal combustion engine. Which type of vehicle is preferable depends on several factors, e.g. purposes, manufacturing strategies, cost, and market.

How far can I drive my car with a partially charged battery? How much will the fuel economy be improved? Questions like these rely on the design of the electric vehicle and foremost on the utilisation of the battery. The different electric vehicles have their own specific requirements for energy and power, the challenge being to find the most optimal design in terms of energy consumption and driveability from a sustainability perspective. The energy demands often translate to all-electric driving range, and the power demands to acceleration and driveability.

The enabler of the electric vehicle is thus really the battery – providing the electric energy. Obtaining the optimal energy and power is an art relying on knowledge both of the vehicle and battery design. The energy and power demands can indeed be fulfilled by a number of battery technologies, but no single technology can fulfil them all perfectly as they have different energy and power characteristics.