There has been much debate about the efficiency of hybrid and electric cars when measured over a full life cycle. Recent studies are demonstrating that these vehicles are indeed holding up to lifecycle scrutiny.
Advances and Critical Aspects in the Life Cycle Assessment of Batter Electric Cars.
Concerns over climate change, air pollution, and oil supply have stimulated the market for battery electric vehicles (BEVs). The environmental impacts of BEVs are typically evaluated through a standardised life-cycle assessment (LCA) methodology. Here, the LCA literature was surveyed with the objective to sketch the major trends and challenges in the impact assessment of BEVs. It was found that BEVs tend to be more energy efficient and less polluting than conventional cars. BEVs decrease exposure to air pollution as their impacts largely result from vehicle production and electricity generation outside of urban areas. The carbon footprint of BEVs, being highly sensitive to the carbon intensity of the electricity mix, may decrease in the nearby future through a shift to renewable energies and technology improvements in general. A minority of LCAs covers impact categories other than carbon footprint, revealing a mixed picture. Up to date little attention is paid so far in LCA to the efficiency advantage of BEVs in urban traffic, the gap between on-road and certified energy consumption, the local exposure to air pollutants and noise and the aging of emissions control technologies in conventional cars. Improvements of BEV components, directed charging, second-life reuse of vehicle batteries, as well as vehicle-to-home and vehicle-to-grid applications will significantly reduce the environmental impacts of BEVs in the future.
Click here for the full paper by authors Eckard Helmers and Martin Weiss.
German LCA testing of Mercedes E350e
Mercedes recently handed their E350e to the German Technical Inspection Authority to prove hybrid power is cleaner than gas in the long run.
One of the biggest criticisms of hybrid cars has been the fact they aren't usually able to back up the claimed fuel efficiency figures in the real world. There's also the question of how much CO2 is emitted in the production of electricity used to charge the battery.
According to the lifecycle analysis conducted by TÜV, building, owning and recycling the new E350e emits around 44 percent less C02 than the outgoing E350 CGI, which offered similar performance to the new hybrid, but ran with a conventional petrol engine instead. The testing assumes the car has been charged using a conventional European plug, but also says using renewable energy to charge the battery could improve that figure to 63 percent over the course of 250,000 km (155,343 mi).