Power & heat with fuel cells

Fuel cells deliver electricity and consume hydrogen and oxygen (air) to this end. Depending on the construction, the electricity yield per quantity of hydrogen is extremely high compared to a gas turbine, for example.

Power and heat are among the most important manifestations of energy. Electricity is universally useable – it is a high-value form of energy. Heat on the other hand, dominates over 50 per cent of the energy consumption in Germany, and so is also a precious energy form. It is mostly produced as a by-product, when energy is converted or is used in the performance of work. We can often see the approximate ratio based on the efficiency of a technology. An Otto engine converts, for example, around 36 per cent of its fuel in motion, the rest is heat for the most part. Extra heat is frequently generated in electricity production in a power station as well. This is already today very often fed into a heat supply system in the combined heat and power process and used for further heating purposes. The intelligent handling of “excess heat” is a necessary step in reducing our overall energy consumption.

Fuel cells deliver electricity and consume hydrogen and oxygen (air) to this end. Depending on the construction, the electricity yield per quantity of hydrogen is extremely high compared to a gas turbine, for example. This is because turbines – and other so-called thermal engines – convert the chemical energy of hydrogen first into heat, then into mechanical and finally into electrical energy. A fuel cell takes the direct electro-chemical route and thereby achieves a typical efficiency rate of between 50 and 80 per cent.

Nevertheless heat also is generated in a fuel cell which is released into the surrounding area - unless we can find a way of using this heat efficiently. The combined heat and power principle seems ideal for this. Fuel cell technology employed in this way also reduces transmission losses in electricity grids or heat supply systems, because often where electricity is needed, heat can be sensibly used as well. And because fuel cells can be made and used in varying sizes, they are perfectly suitable for decentralised applications and grid-independent “island solutions”. Electricity and heat production then happens at the place of consumption – at home, in industry or on the move.

Home-made energy and heat

Fuel cells in your own home? It may sound unusual, but it is in fact a pioneering technology supplying the home with electricity and heat. A so-called fuel cell heating appliance is installed instead of the conventional boiler and connected to the natural gas grid. The benefits are that the appliances generate both electricity and heat at the same time. This way no energy is lost, and because the electricity production occurs on location and only according to demand, there are no distribution losses. Altogether around half of the primary energy required up to now for household supply can be saved in this manner. And that is no small amount, as about 30% of the primary energy demand in Europe currently comes from residential buildings.

Callux lighthouse project
In the largest nationwide field trial Callux tested and further developed the energy-saving and climate-friendly technology of fuel cell heating appliances in everyday use. The project had been initiated by partners from the energy and the heating appliance industries and supported by the Federal Ministry of Transport and Digital Infrastructure (BMVI). Funding was provided by the National Innovation Programme for Hydrogen and Fuel Cell Technology (NIP), which is coordinated by NOW GmbH. The entire investment from industry and the public sector amounted to around 86 million euros.
Archive callux / german

On the move

Fuel cells operate silently, highly efficiently and generate no damaging emissions. In addition, their capacity is unlimited in principle, as long as sufficient hydrogen or other fuels such as, for example, methane, propane or methanol are available. Therefore they are particularly suitable for mobile and location-independent electricity supply.

Because of their characteristics, fuel cells can be used anywhere where conventional combustion engines dominate the field today. Their area of application is in fact greater, as fuel cells are available in a wide variety of sizes and can also be operated in areas sensitive to emissions and noise, like in nature conservation areas and environmental zones or at designated quiet periods in residential areas.

e4ships lighthouse project
Shipping is responsible for almost three per cent of global CO2 emissions. Added to this are pollutants such as sulphur dioxide, nitrogen oxides and soot particles, which come from using heavy oil as fuel. In order to ease the burden on both people and the environment, shipyards, shipping companies, fuel cell manufacturers and classification societies joined forces in 2009 in the NIP lighthouse project “e4ships”. Coordinated by NOW, they develop and test new technologies that could replace conventional ship aggregates. The total investment amount is around 50 million euros with the costs equally split between the partners on the one hand and the Federal Ministry of Transport and Digital Infrastructure (BMVI) on the other.
Website e4ships