| Back to: Rocky Mountain Institute--Home Page > Transportation > The Hypercar® Concept > Hypercar Design and Technology—Whole-System Design > How to Design a Better Vehicle > Hybrid-Electric Drive |
 |
Fuel Cells and Hypercar® Vehicles Developed in the 1960s for the space program, fuel cells generate electricity directly by chemically combining stored hydrogen with oxygen, producing hot water—their only emissions—as a byproduct. (The process is essentially the reverse of electrolysis, where electricity is used to split water into hydrogen and oxygen.) Fuel cells function sort of like batteries, except that instead of being recharged, they're simply fed a continuous supply of hydrogen gas and air. Because they convert fuel directly into electricity, they are by definition a hybrid-electric vehicle technology. 
Fuel cells are an exciting potential power source for vehicles of the future because they're very efficient, produce low noise and emissions, are compatible with renewable energy sources, are reliable and durable (since they have almost no moving parts), and can be packaged to fit a wide variety of auto designs. Efficiency is expected to be about 50 percent in automotive use. Currently, however, fuel cells are very expensive because they're not produced in volume, and the widespread refueling infrastructure that the most efficient fuel-cell cars would require doesn't yet exist. A fuel-cell-powered car can either carry its own supply of hydrogen in a pressurized tank, or derive the hydrogen on demand from natural gas or any liquid fuel in a chemical reactor called a "reformer." From an engineering design standpoint, storing the hydrogen onboard turns out to have a lot of advantages: by eliminating the reformer, it significantly reduces weight, cost, complexity, fuel consumption, and emissions. The only real disadvantage of onboard hydrogen storage—bulk—is solved by the Hypercar® concept, since Hypercar® vehicles' lower fuel requirements would enable the storage tank to shrink to normal size. (Safety turns out not to be a problem.) Some observers believe onboard reforming may be a necessary transitional step until a hydrogen infrastructure develops, but the Hypercar Center® does not. Fuel-cell technology has advanced significantly in the past few years, and a handful of automakers, (including Daimler-Benz, GM, and Toyota) have shown prototype fuel-cell-powered vehicles. Most of these prototypes have been quite heavy, requiring large (and therefore expensive) fuel-cell power plants, which has led some observers to predict that it may take 15 to 20 years for fuel cells to become economical. Yet Hypercar® vehicles could accelerate the adoption of fuel cells, because the Hypercar® vehicle's much lower power requirements would require far less fuel-cell capacity than a heavy, high-drag conventional car. This should make fuel cells affordable in Hypercar® vehicles years earlier than in conventional vehicles. For more detailed information on fuel cells, see our Fuel Cells and Hydrogen page in the Energy section of this web site. Used with permission. |
| General Information Inquiries | Privacy Statement | Report Technical Problems |
rmi.org is published by Rocky Mountain Institute. 1739 Snowmass Creek Road | Snowmass, CO 81654-9199 | Ph: 970.927.3851 Copyright 1999–2006. All Rights Reserved. thomfish@rmi.org Other RMI web sites include: Winning the Oil Endgame (www.oilendgame.org) Natural Capitalism (www.naturalcapitalism.org) National Energy Policy Initiative (www.nepinitiative.org) Small Is Profitable (www.smallisprofitable.org) The Community Energy Opportunity Finder (www.energyfinder.org) Powered by Site Management Console |