As many cities and countries aim to tackle the poor air quality in regions globally, there is an increasing demand for new energy vehicles in the transition away from the polluting petrol and diesel-based technologies of the last century. Each generation of the global vehicle emission standards released has continued to lower the application of fossil fuels due to emission controls. The introduction of the Euro 7 standard will limit the capability of combustion engine technology to meet specific emission regulations. Electric mobility (e-mobility) has become a rapidly developing opportunity to contribute to nations’ climate and development goals, including climate change mitigation, fiscal burden reduction (for oil-importing economies), energy efficiency, sustainability, air quality improvement, and promoting modal shift where applicable. Global experiences show that with the appropriate technology, policy, and financial interventions, e-mobility could present opportunities to not only decarbonize both the energy and transport sectors, but also create a diverse set of social, environmental, and economic co-benefits, including jobs, due to the establishment of new value chains.
Along the energy transition for vehicle technologies towards new energy vehicles, there are a number of variations that are being introduced into the market. Hybrid Electric Vehicles (HEVs) have two complementary drive systems, an internal combustion engine with a fuel tank, and an electric motor with a battery. Both the engine and the electric motor can operate at the same time. HEVs cannot be recharged from the electricity grid – all their energy comes from the engine and from regenerative braking. Plug-in hybrids (PHEVs) use an electric motor and battery that can be plugged into an external source of electricity to charge the battery but also has the support of an internal combustion engine that may be used to recharge the vehicle’s battery and/or to replace the electric motor when the battery is low. A battery electric vehicle (BEV) runs entirely using an electric motor and battery, without the support of a traditional internal combustion engine, and must be plugged into an external source of electricity to recharge its battery. Like all electric vehicles, BEVs can also recharge their batteries through regenerative braking, which uses the vehicle’s electric motor to assist in slowing the vehicle and recover some of the energy normally converted to heat by the brakes. Fuel cell electric vehicles (FCEVs) use electricity to power an electric motor like all-electric vehicles. However, in contrast to other electric vehicles, they produce electricity using a fuel cell powered by hydrogen, rather than drawing electricity from only a battery. The amount of energy stored onboard is determined by the size of the hydrogen fuel tank. This is different from a battery electric vehicle, where the amount of power and energy available are both closely related to the battery’s size.
With different technology types and mixes, there is a consideration of energy efficiencies across each of these. On the transition of the energy sector to renewables, the image profiles the efficiency of different passenger vehicle technology pathways based on a common baseline of 100% renewable electricity.
Figure 1: Efficiency of different passenger vehicle technology pathways
With battery electric vehicles, only five percent of the energy is lost before the electricity is stored in the vehicle’s batteries. When the electrical energy used to drive the electric motor is converted, another 18 percent is lost. This gives battery electric vehicles an efficiency level of between 70 to 80 percent, depending on the vehicle model.
With hydrogen-powered vehicles, the losses are significantly greater: 39 percent of the energy is already lost during the production of hydrogen through electrolysis. Of this remaining 61 percent of the original energy, another 31 percent is lost when hydrogen is converted into electricity in the vehicle. This means that the hydrogen-powered electric vehicle only achieves an efficiency of between 25 to 35 percent, depending on the vehicle model. With traditional internal combustion engine vehicles, when alternative fuels are burned, the efficiency is even worse: only 10 to 20 percent overall efficiency.
By Hiten Parmar, Executive Director: The Electric Mission
Hiten Parmar is a seasoned expert and distinguished thought leader, holding over 20 years of professional experience. He plays a pivotal role as a liaison for various sector-related forums both locally and internationally, championing the advancement of the electric mobility ecosystem. Encompassed with a Master’s Degree in Electrical Engineering and an Honours in Business Administration, Hiten is mission-driven on the technological progress within the global industry. His vision extends to a world characterized by sustainable and equitable mobility and energy systems, a vision he fulfills as the Executive Director of The Electric Mission in South Africa.
