Energy, Transport, & the Environment pp 223-252
Using Electric Vehicles for Road Transport
Road vehicles account for almost half of the energy used in all transport modes globally. Reducing energy use in vehicles is key to meeting the forecast increase in demand for transport, while improving energy security and mitigating climate change. Non-powertrain vehicle options may reduce fuel consumption by at least 15%. Electric motors are the significant powertrain option to reduce energy use in vehicles because they are more efficient than the internal combustion engine and can recover a portion of the vehicle kinetic energy during braking. Conventionally, batteries are used to meet both the power and energy demands of electric vehicles and their variants. However, batteries are well-suited to store energy, while ultra-capacitors and high-speed flywheels are better placed to meet the bidirectional, high power requirements of real-world driving. Combining technologies with complementary strengths can yield a lower cost and more efficient energy storage system. While pure and hybrid electric vehicles use less energy than internal combustion engine vehicles, their ability to mitigate climate change is a function of the emissions intensity of the processes used to generate their electricity.