Trends in Sustainable Transportation

It is easily forgotten that a century ago electric vehicles had a dominant market share over steam and internal combustion automobiles. Quiet, clean, reliable and easy to use - the 'ladies car' - the EV suffered range and performance limitations, and was quickly overwhelmed in the market by rapidly improving gasoline vehicles. Driven in large part by the quest for improved fuel efficiency and emissions - and accelerated by design opportunities and attractive customer features - the re-electrification of the motor vehicle is progressing rapidly. Electrification ranges from the mundane, such as small motors, pumps and comfort features in conventional vehicles, through a spectrum of hybrid systems (that use a small, high-power battery and electric motors to achieve a dramatic improvement in fuel economy) to a proliferation of new all-electric vehicle concepts. At the same time, our public dialog often seems to accept as fact that automobiles are responsible for a large share of GHG emissions and are far less efficient than other transportation modes, that plug-in hybrids (equipped with a larger battery and external charging capability) and pure EVs will reduce greenhouse gas emissions while reducing the cost of personal transportation, that deployment of EVs and PHEVs will somehow accelerate the introduction of clean electric generation, and that battery technology has progressed to the point that a fully capable EV is feasible. Intended to promote rational discussion rather than particular solutions, this presentation combines first-principles considerations of fuel and energy storage, publicly-available energy data and results of our own vehicle studies to test these assumptions. It is found that an advanced hybrid electric vehicle is a surprisingly efficient transportation device, and with growing availability of renewable fuel it is possible to achieve sustainable personal transportation without a dramatic sacrifice of functionality. It is also suggested that public policy must be carefully designed to assure alignment between the goals of environmental responsibility and energy independence.