Application of Hydrogen
The use of hydrogen as an energy carrier will change many facets of our life in the future. Together with the fuel cell it has the potential to revolutionise the whole energy economy.
Hydrogen facilitates the use of renewable energy sources: As a fuel in traffic or as a fuel for the co-generation of electric power and heat. Whoever wants to cook or to drive with hydrogen generated from solar energy or from wind power will be able to do so.
Generally one can differentiate between three main areas for the use of hydrogen: Stationary, mobile and portable applications.
Mobile Hydrogen Applications
In principle all means of transport we know today could be powered by hydrogen. There are two possibilities for doing so: Hydrogen is burnt in conventional engines instead of gasoline. The other option is the use of fuel cells which are generating electric power for an electric motor in the vehicle.
Using fuel cells in road transport applications has some decisive advantages: There is only water emitting from the exhaust, it operates without noise and without vibrations and it is more efficient than a combustion engine - so it saves energy. When a fuel cell car is waiting at a traffic light there is no noise because the engine does not work. The noise caused by accelerating is much reduced as well. Our cities will become much quieter.
Stationary Hydrogen Applications
- Passenger cars with fuel cells
All over the world the major car companies are developing cars with fuel cell drive systems. In Germany mainly Daimler, GM/Opel and Ford are the first to do so. BMW has presented hydrogen powered cars very early but they are still concentrating on combustion engines. Since the year 2007 the first hydrogen series vehicles of the 7-series have been leased to customers, all in all about 100 vehicles are planned.
Carmakers in the USA, Europe and Japan have announced to offer fuel cell cars on the market from 2012 onwards. As an infrastructure is still missing the circle of customers is limited to typical fleet operators. It is planned to offer hydrogen cars to all groups of customers until 2018, essential parts of an infrastructure should exist until then. Since 2003 test fleets of many Japanese , Korean, US and German carmakers have been leased to selected customers, as for example in the "Clean Energy Partnership Berlin (CEP)" or in the "California Fuel Cell Partnership" in the USA . All in all and throughout the world some hundred vehicles are being tested. The most important issue is the building of an appropriate infrastructure. About 10.000 filling stations would be enough to provide the basic supply all over Europe.
- Hydrogen powered city buses
For buses the two different concepts of internal combustion engine and fuel cell exist as well. Compared with diesel buses they both have the advantage of greatly reduced pollutant emissions.
In the framework of different European projects hydrogen busses are operating as public service vehicles. By now the most important project for Europe is called "HyFLEET:CUTE", 47 busses are tested at 12 locations. The most important locations are Hamburg, 9 Daimler Citaro fuel cell busses are running there, and Berlin, with 14 busses with a hydrogen-combustion engine of MAN.
- Trucks, trams, railway engines and ships
Concepts for the usage of hydrogen or fuel cells exist for nearly all means of transport. The usage in trams or railway engines is discussed for all applications especially in places where no overhead lines exist or would be disturbing. In these cases additional costs for hydrogen powered railway engines are opposing the costs for overhead lines.
The use of hydrogen and fuel cells in trucks has not yet been intensely tested, as diesel engines work very efficiently on long-distance rides.
The use of fuel cells in delivery vehicles in cities, however, is very interesting as these vehicles are usually part of a fleet and their daily mileage is limited. In the evenings they can be refilled in the depots. Delivery vehicles like these are being tested by different parcel services.
Emissions of ships which are used in urban areas, like passenger ferries or pleasure boats, could be considerably lowered. In addition these ships would be very quiet and really comfortable for the passengers because the fuel cell works without noise. On big ships this would apply to the electric power supply on board, which allows for the generators to be put down in the harbour. In Hamburg the first fuel cell powered Alster steamboat will be in operation in 2008.
- Hydrogen powered aircrafts
Since the beginning of the 80's the Russian manufacturer Tupolev has worked on aircraft versions with cryogen energy supply. In 1988 Tupolev presented a TU 154 of which the right of the three engines was modified so that it could be powered by liquid hydrogen and also tanks for hydrogen were installed.
The engine was working successfully for the whole flight phase which lasted more than 100 hours.
Although the big European aviation industry like Dornier and Airbus have considered and tested hydrogen aircrafts, there are no serious efforts in this field at present. There are concepts, however, to use fuel cells for the power supply on board and use the emitting water on board to reduce flight weight.
Fuel cells are like small thermal power stations. They convert the energy carrier hydrogen into electric power and heat. The cogeneration of electric power and heat makes the best possible use of the originally used primary energy carrier.
Such cogeneration fuel cell power stations can be realised in different construction sizes. Beside small decentralised power stations with a power range between 200 kW and some megawatt, especially small systems are an interesting option. Within the power range of common home heating these systems do not only deliver heat but also electric power to feed into the power grid. Millions of such residential fuel cells can be seen as a large power plant, a power plant which can for example also serve as back up unit in a wider supply scenario mainly based on renewable energies.
Today residential fuel cell systems for the homes work with natural gas and need a reformer to produce the hydrogen needed. In Germany many manufacturers of heating systems are working on systems like that. In Japan far more than 1000 systems were installed in 2007 and several thousands are to follow in 2008. From 2011 onwards the systems in Japan are to go into mass production. Many oil and gas companies are accelerating the development in Japan.
If produced in large numbers fuel cells for the home have the potential to be hardly more expensive than a conventional heating boiler although they produce electric power more or less as a "by-product". This way the supply with heat energy is not yet CO2 free, but the energy needed for the generation of electricity is used more efficiently.
Portable Hydrogen Applications
A great variety of possible applications for fuel cells and hydrogen can be found in the energy supply of portable devices: mobile phones, laptops, MP3-Player, camcorders and many other things could be powered by hydrogen and by fuel cells in the size of batteries.
The operation time of a notebook computer powered by a fuel cell exceeds the operation time of computers powered by conventional accumulators by far. Primarily used for this purpose are direct-methanol fuel cells. The fuel cells are powered by a methanol cartridge. When the methanol draws to an end one simply inserts a new cartridge, the accumulator is full again and ready for use for many hours.
Fuel cells which are even smaller, so called micro fuel cells, could be integrated in mobile phones. Prototypes with an operation time of fifty hours have already been presented.
Also portable applications with higher power rating are being developed. In the USA lighting appliances on some construction sites in remote regions are already powered by fuel cells. Provided there is a big enough tank these systems work for weeks and they are cheaper to run than batteries with equivalent capacities. The same applies to the energy supply of remote transmitting stations of mobile phone providers.