Alternative Transportation

What’s new in the development of transportation systems that might reduce our dependence on hydrocarbon fuels? This article takes a quick look at some innovations recently in the news.

The Biogas Train

Sweden is testing the world’s first environmentally friendly biogas-powered passenger train. The biogas train has been developed jointly by a Swedish biogas company and a Swedish railways subsidiary at a cost of 10 million kronor (€1.08m; US$1.3m). The train is powered by two biogas bus engines and can run for 600 km before it needs to be refuelled. It has one carriage carrying up to 54 passengers and can reach speeds of up to 130 kph.

The prototype has been built by replacing the diesel motors in a 25-year-old engine with 11 gas tubes. Sweden already has experience with biogas as a transportation fuel. According to the Swedish environment ministry the country has 779 biogas buses and more than 4,500 cars that run on a mixture of petrol and either biogas or natural gas.

The Swedish makers of this biogas train had India in mind during the development of the train. India, besides having the largest railway network in the world, has vast stretches of rail tracks using diesel engines where the biogas train could be more environmentally sound and economical. India is already exploring environmentally friendly energy sources and has buses and taxis that run on compressed natural gas in New Delhi.

There are more than 3000 biogas plants in Europe, where production of biogas is a mature technology. Biogas is made from the decomposition of shredded plant materials and animal waste by micro- organisms in anaerobic conditions. Biogas emits far less carbon dioxide than traditional fossil fuels and has the added advantage that it can be produced locally.

Biodiesel is a blend of diesel and biogas and can be used in many regular diesel vehicles. It has been used successfully in school and transit buses, refuse haulers, military support vehicles and farm equipment. According to the U.S. National Biodiesel Board, using a biodiesel fuel blend can significantly reduce vehicle emissions.

Hybrid Vehicles

Most of the major vehicle manufacturers are moving towards the development of hybrid vehicles that use both regular gasoline engines and electric batteries to power the vehicle at low speeds. A typical full hybrid has a four-cylinder gasoline engine and a nickel-metal hybrid battery. The gasoline engine shuts down automatically at stop lights and when coasting and the hybrid can run solely on battery power at speeds up to 40 kph, when internal combustion engines are least efficient. The battery is recharged by regenerative braking, which uses the energy released from the wheels during braking. This energy is converted by the motor into electricity which is stored in the battery until needed. This system overcomes a drawback of earlier electric cars which had to be recharged by plugging into a wall outlet. The electric motor provides additional power to assist the engine in accelerating, passing or hill climbing. A smaller, more efficient engine than those in regular gasoline vehicles is used.

Electric Vehicles

A Norwegian company formerly owned by Ford is developing hybrid electric cars. TH!NK Nordic has been granted €1.35m by the Research Council of Norway towards the development of a prototype fuel cell/electric hybrid vehicle. The car, called TH!NK hydrogen, runs either on its batteries, which can be charged from a wall outlet, or on hydrogen. Either way, the vehicle has zero emissions. Most of the time, TH!NK hydrogen operates like a normal electric car. Running on batteries, the car has a 150 km range that covers normal daily driving needs and is especially useful in a city. For longer trips the TH!NK hydrogen has a hydrogen fuel cell that charges the batteries while it is being driven. The hydrogen tank doubles the driving range to 300 km and can be refilled in minutes.

While a normal combustion engine has an energy efficiency of approximately 30% and hydrogen fuel cell has an energy efficiency of 50%, batteries are over 90% energy efficient.

Several years ago both Ford and GM announced their intentions to abandon their electric cars. These cars had been leased to customers in the US and now the returned cars are being crushed and recycled. Both models were intended to be city runabouts and the market was not big enough for commercial success. The limited driving range did not appeal to US customers, who are used to being able to drive long distances. Having to recharge the batteries overnight from a wall outlet was inconvenient and used electricity from the national grid. GM learned from their experience with the electric car that customers are unwilling to buy products unrelated to their lifestyles, no matter how environmentally friendly or economic. Also, supporting infrastructure must be available if a vehicle is to have mass appeal. Undeterred, Mitsubishi announced recently that it will be mass-producing electric cars by 2010.

Hydrogen fuel cells

Motor manufacturers are also investigating the feasibility of hydrogen fuel cells as energy sources. Fuel cells were originally developed for the U.S. Space program to provide power for the space shuttles. The hydrogen is passed through a membrane that converts the energy in the fuel directly into electricity to power the electric motor. The by-product of this process is water, making this a zero emissions vehicle. Honda has developed a hydrogen-powered fuel-cell car which is being leased to a California family for testing. The family of four will use the car to commute, shop and take the children to school and then give feedback to Honda on the car’s performance. The car can travel up to 300 km on a tank of hydrogen.

Proponents of hydrogen fuel, which produces electricity and water vapour when it burns, believe it will eventually compete with petroleum, but currently its high costs, the need for more research and a scarcity of hydrogen fuel stations are barriers to its being adopted by the mass public. California’s governor, Arnold Schwarzenegger, last year signed an executive order aimed at establishing hydrogen stations across the state by 2010.

Some cities are pioneering the use of hydrogen-powered vehicles. For example, Hamburg, Germany, has a fleet of hydrogen vans in full operation and Chicago ran a successful two-year demonstration project with fuel cell powered buses. The vehicles were said to have performed well in both summer and winter. Driver and passenger reaction to the program and the buses was positive. Drivers reported a smooth, quiet ride, absence of fumes and good acceleration.

Compressed Air Technology

A French company, Moteur Development International, has unveiled a car engine that uses compressed air technology ( CAT). Power comes from fresh air stored in reinforced carbon-fibre tanks beneath the chassis. Air is compressed to 4,500 psi and fed into four cylinders where it expands and drives specially designed pistons. When the air tanks are empty the driver can switch to fuel mode. The engine will be able to use a variety of fuels, such as gasoline, gas oil, biodiesel, gas, liquidized gas, ecological fuel or alcohol. Recharging the onboard tanks takes about four hours using the car’s small compressor. Service stations equipped with special air pumps would be able to replenish the tanks in about three minutes.

Two technologies have been developed to meet different needs: single energy compressed air engines and dual energy compressed air plus fuel engines. The single energy engines have been designed for city use, where the maximum speed is 50 km/h and where polluting vehicles may be penalised, e.g., in London, where gasoline powered vehicles are charged a fee to enter the city. The dual energy engine will work exclusively with compressed air while it is running under 50 km/h in urban areas but when the car is used outside urban areas at speeds over 50 km/h, the engines will switch to fuel mode.

Gear changes are automatic, powered by an electronic system developed by MDI. A computer controls the speed of the car and is effectively continuously changing gears.

The idea of using compressed air isn’t new. Writer Jules Verne predicted in the 1860s that the technology would be used to power cars in Paris by the late 20th century. Some primitive engines date to the early 1900s and compressed air has been used for years to start race cars.

Now, if only we could do something about all those fuel-guzzling aircraft……(for an interesting article see www.bl.uk/collections/patents/greenaircraft.html).

Information for this article was complied using some material gathered from these sources: www.fueleconomy.gov, www.fordvehicles.com, www.canadiandriver.com, www.eere.energy.gov, www.theaircar.com, www.motoring.co.za, www.hyweb.de, www.familycar.com, www.gmcanada.com, Agence France-Presse, Reuters.

For comprehensive information and examples of successful applications of renewable energy in Canada visit the website www.canren.gc.ca and for information on the latest US developments in the use of alternative energy sources, see www.renewableenergyworld.com/rea/home.