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

Investigating the technical, economic and environmental performance of electric vehicles in the real-world: A case study using electric scooters

This work presents the findings of a small-scale electric scooter trial in Oxford, United Kingdom. The trial scooters were instrumented with global positioning satellite data loggers and energy meters to record their time of day usage and charging regimes. The scooters were most likely driving at 09:00, 12:45 and 17:15 and charging at 10:15-10:40. The electric scooter normalized mains-to-wheel energy use was 0.10 kWh km-1. The electric scooter total operating costs (electricity and battery replacement) of £0.045 km-1 is 24% greater than the best selling equivalent petrol motorcycle and 1.7 times lower than the best selling car. The electric scooter uses 0.45 MJ km-1, or 2.9 times and 6.1 times less than the petrol motorcycle and car, respectively. Further, the electric scooter can achieve zero carbon dioxide equivalent (greenhouse gas, GHG) emissions when electricity from renewable energy sources is used. In 2008, there were 247 000 motorcycles in the UK vehicle fleet of equivalent size to the trial scooter. Scaling up the electric vehicle fleet size accordingly would avoid 0.60 billion car or motorcycle kilometres and 54-110 kt associated GHG. The fleet would require 59 GWh, or 0.015% of total annual generation with a time-shifted, peak demand of 250 MW, or 0.44% of the 58 GW maximum national demand. © 2011 Elsevier B.V. All rights reserved