Fuel CellThe Electricity-Generating Heating System
Become energy independent with the electricity generating heating: the Fuel Cell
For a long time, fuel cells were considered to be the electricity generating heating for the future. Meanwhile, more and more manufacturers offer fuel cell devices or fuel cell compact devices. Their big advantage is the combination of power generation with heat generation like a combined heat and power plant. The devices generate electricity and heat for use locally in the home. This means that users have to source less electricity from the utility and the saved electricity costs ensure the fuel cell heating system’s profitability.
Functioning of a Fuel Cell-Heating
Fuel Cell heatings are in principle small combined heat and power plants (micro CHP). Using natural gas, they generate electricity and heat. Conventional micro CHPs work with an internal combustion engine. However, the fuel cell operates on the principle of “cold combustion”. It generates electrical energy from the chemical reaction energy that results from the connection of hydrogen and oxygen to water. Such a connection we may know from the chemistry lessons back in school as the bang-gas reaction. In the fuel cell, this reaction is controlled and happens without explosion.
Hydrogen, which is split off from the supplied natural gas, and oxygen from the ambient air are introduced into two adjacent chambers. Thus, it cannot come to an explosive connection of the two substances. The hydrogen is split into protons and electrons. The protons can pass through the thin separation layer and react to water. Meanwhile, the electrons travel via a cable from the anode to the cathode and thus generate electricity. The heat generated by the reaction is used by the system for heating and warm water. Another waste product that remains is water.
A common design is the SOFC fuel cell, i.e. solid oxide fuel cell (SOFC). It has a thin ceramic layer between the cathode and anode as electrolyte. It works with high temperatures between 650 and 1,000 degrees Celsius and has a higher efficiency in power generation.
Since the thermal performance of fuel cell devices is insufficient to meet the heat demand in a household, the manufacturers combine them with an additional gas boiler to cover peak load. Compact fuel cell heatings are already fully equipped with a gas boiler, a buffer tank for heating, a storage tank for hot water and a unit for the energy management.
Fuel Cell Economics
The costs of a fuel cell heating system is relatively high compared to conventional heaters. However, they are more efficient and also provide added-value through power generation. You can use the electricity directly in the household and thus save on the more expensive electricity from your energy provider. For electricity, which you cannot use and also cannot store, you get a fee when feeding it into the grid. Savings on electricity purchases and electricity sold ensure that fuel cells are economically interesting despite the high initial investment.
Another factor that makes fuel cell systems interesting for use in single-family homes is its attractive subsidy programme. For stationary fuel cell heating appliances with a capacity of 0.25 to five kilowatts, the KfW (Kreditanstalt für Wiederaufbau) offers a subsidy scheme for investments in new and existing residential and non-residential buildings (program 433). A maximum of 40 percent of the costs for the device, possibly for an additional heater, for assembly, for a ten-year maintenance contract and for an energy efficiency expert are subsidized. The subsidy consists of a fixed amount of 5,700 euros and a performance-related amount of 450 euros per 100-watt electric power started.
The KfW-funding-programme for fuel cells can also be combined with other KfW Bank programmes. Some Federal States also offer support for Fuel Cell heating – if a combination of the subsidy schemes is possible should in any case be examined beforehand. Additionally, in the operation of the device is still made interesting by the remuneration for the injected electricity according to the CHP law (KWKG). The application for the feed-in tariff must be submitted via the BAFA ministry.
Increase your independence with Storage & PV
Fuel Cells already contribute to your independence from the electricity supplier and future price increases. In combination with a photovoltaic system and a power storage you can increase this percentage even more. It is important that in this case the fuel cell is operated depending on the power requirement. If the power from the photovoltaic system is insufficient, then the fuel cell can supply the missing power. A sufficiently sized heat storage ensures that there is always enough heat available.
Whether the combination of fuel cell with a photovoltaic system pays off, must be checked for each individual case. It is important to ensure that the power generation from the fuel cell is not reduced and thus the economic efficiency deteriorates.
Find further information about the Cuel cell and calculate its yields here.
We remain at your disposal for all questions about fuel cells.