Top Emerging Tech 1/10: Fuel-cell vehicles

Zero-emission cars that run on hydrogen

Fuel-cell vehicles have long promised several major advantages over those powered by electricity or hydrocarbons. The technology has only now begun to reach the stage where automotive companies are planning launches for consumers, however. Initial prices are likely to be in the range of $70,000 but should come down significantly as volumes increase within the next couple of years.

Unlike batteries, which must be charged from an external source and can take from five to 12 hours depending on the car and charger, fuel cells generate electricity directly, using hydrogen or natural gas. In practice, fuel cells and batteries are combined, with the fuel cell generating electricity and the batteries storing it until demanded by the motors that drive the vehicle. Fuel-cell vehicles are therefore hybrids and will likely also deploy regenerative braking, which recovers energy from waste heat, a key capability for maximizing efficiency and range.

Unlike battery-powered electric vehicles, fuel-cell powered ones have a long cruising range—up to 650 kilometers per tank (the fuel is usually compressed hydrogen gas); a hydrogen fuel refill only takes about three minutes. Hydrogen is clean-burning, producing only water vapor as waste, so fuel-cell vehicles using hydrogen will be zero-emission, an important factor given the need to reduce air pollution.

There are a number of ways to produce hydrogen without generating carbon emissions. Most obviously, renewable sources of electricity from wind and solar sources can be used to electrolyze water—although the overall energy efficiency of this process is likely to be quite low. Hydrogen can also be split from water in high-temperature nuclear reactors or generated from fossil fuels such as coal or natural gas, with the resulting carbon dioxide captured and sequestered rather than released into the atmosphere.

As well as the production of cheap hydrogen on a large scale, a significant challenge is the lack of a hydrogen distribution infrastructure that would be needed to parallel and eventually replace gas and diesel filling stations. Long-distance transport of hydrogen, even in a compressed state, is not considered economically feasible today. Innovative hydrogen storage techniques, such as organic liquid carriers that do not require high-pressure storage, however, will soon lower the cost of long-distance transport and ease the risks associated with gas storage and inadvertent release.

Mass-market fuel-cell vehicles are an attractive prospect because they will offer the range and fueling convenience of today’s diesel and gas-powered vehicles while providing the benefits of sustainability in personal transportation. Achieving these benefits will, however, require the reliable and economical production of hydrogen from entirely low-carbon sources as well as its distribution to a growing fleet of vehicles, expected to number in the many millions within a decade.

Note - Well not a surprise winner and not a new idea. The difference is we are close to seeing mass market fuel cell vehicles and that will change everything.

Source: Scientific American