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Fuel cell heating: funding, installation, costs
Fuel cell heating: funding, installation, costs

Video: Fuel cell heating: funding, installation, costs

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Fuel cell heating not only produces heat and hot shower water, but also electricity as a “waste product”. In order to use a fuel cell sustainably, it therefore makes sense to keep it running permanently: This is how you generate a lot of heat and electricity. You can find an overview of everything relating to the promotion, installation and energy costs of fuel cell heating here.

Table of contents Table of contents fuel cell heating: advantages and disadvantages

  • Fuel cell heating: An overview of the most important things
  • How does a fuel cell heater work?
  • Installation: Requirements for installation
  • Fuel cell heating: efficiency and areas of application
  • Fuel cell heating: The costs at a glance
  • Legal provisions and grants

Table of contents Table of contents fuel cell heating: advantages and disadvantages

  • Fuel cell heating: An overview of the most important things
  • How does a fuel cell heater work?
  • Installation: Requirements for installation
  • Fuel cell heating: efficiency and areas of application
  • Fuel cell heating: The costs at a glance
  • Legal provisions and grants

Fuel cell heating: An overview of the most important things

  • Generation of energy in the form of heat and electricity in one device at the same time.
  • The system is particularly energy efficient.
  • The high acquisition costs are offset by low energy costs.
  • Fuel cell heaters make you independent of the electricity provider.
  • Grants are possible for the type of heating.

How does a fuel cell heater work?

In short: In a fuel cell heating system, gas is chemically decomposed, producing heat and electricity. The principle is also known under the term "combined heat and power". This question can be answered in somewhat more detail if the heater is broken down into its components. The most important part is the “stack”, which combines several fuel cells into one block. The structure of a cell consists of two electrodes (anode and cathode) and an intermediate, semipermeable membrane or an ion conductor. To complete the device, an inverter and a reformer, as well as oxygen and natural gas as energy sources are added. Depending on the type of fuel cell heating, there is also an integrated gas condensing boiler with which peak loads can be covered, as well as a hot water tank. This combination is then a complete hot water, heating and electricity system. In parallel, there are also devices that only contain the fuel cell device, which can then be supplemented to an existing gas condensing boiler.

Die Brennstoffzelle der Brennstoffzellenheizung
Die Brennstoffzelle der Brennstoffzellenheizung

In fuel cell heating, hydrogen molecules generate heat and electricity on their way through the fuel cell.

Photo: Viessman

The "fuel cell" is usually a hydrogen-oxygen fuel cell. Natural gas is fed into the reformer in the heating system, where it is converted into hydrogen and carbon monoxide. The carbon monoxide is processed into carbon dioxide in a second step. The newly generated hydrogen can then be fed to the fuel cell module inside the heater. With the help of a catalyst, it is divided into positive ions and negative electrons on the anode side of the fuel cell. The negative electrons produce direct current on their way from the anode to the cathode (via the electrical conductor). The inverter already mentioned converts the generated direct current into alternating current and makes the current available for use. The ranking is usually as follows: First, the demand of the house electricity is covered, then an existing battery storage - for example for an electric vehicle - is charged. The remaining surplus is fed into the power grid and reimbursed by the supplier. The positive ions, in turn, also diffuse through the membrane to the cathode and release heat and water when they react with oxygen. The heat generated is absorbed within the system and passed on to the heat exchanger. This then heats the radiator, surface heating (for example underfloor heating) and the hot water.

This chemical process within the fuel cell is called "cold combustion". Cold because there is no conventional combustion in which a raw material is burned to generate heat.

Vitovalor PT2 Brennstoffzellenheizung
Vitovalor PT2 Brennstoffzellenheizung

On the top right is a gas condensing boiler, on the bottom right the fuel cell module and on the left the hot water tank. This creates heat and electricity in the smallest space in fuel cell heating.

Photo: Viessmann

Installation: Requirements for installation

The requirements for installing a fuel cell heater are analogous to those of a condensing boiler:

  1. Since natural gas is the basis for the generation of the required hydrogen, a gas connection is essential. This can be done either by a direct connection from the gas supplier or by an outdoor tank.
  2. An air-flue gas system (LAS) as a fresh air supply for heating and as an outlet for the flue gases. As an alternative, an existing chimney can also be used, provided the responsible district chimney sweep releases it as intact.
  3. Since the fuel cell heating is a relatively large device, the space requirement is higher than, for example, with a pure gas condensing boiler. However, the advantage of fuel cell heating is that it is compact in itself. This eliminates the complex piping outside the housing.
Brennwertheizung
Brennwertheizung

The system is compact for clean installation and order in the technical room.

Photo: Remeha

Fuel cell heating: efficiency and areas of application

The area of ​​application of the fuel cell is extremely diverse. In the single-family home sector, it is currently still the underdog, whereas it is used more frequently as a combined heat and power plant in large industrial plants or apartment buildings. Its versatility is particularly evident outside of pure heating. It is particularly popular with moving objects when an internal combustion engine cannot be used. For example, fuel cell technology can be found in forklifts, buses and cars (the latter with a range of up to 800 kilometers) and in submarines and trains. With this use, however, the focus is primarily on the generation of electricity - the heat generated is then the waste or by-product.

The principle of combined heat and power makes fuel cells particularly efficient. It generates heat and electricity with just one chemical reaction. The big advantage is that a house can be operated almost independently - an interesting factor for a low-energy house or a plus-energy house. If the heat generated at peak load times is not sufficient to heat the house or hot water, for example, a gas condensing boiler is switched on in today's complete systems.

Since this uses the same raw material as the fuel cell, namely natural gas, the systems complement each other ideally. Due to the fact that the fuel cell's capacity can only be controlled to a limited extent, the installation makes a lot of sense in order to establish a constant basic supply.

Another great advantage is that, compared to a photovoltaic system, electricity generation is not dependent on the sun, but takes place at any time of the day, especially at night, and at any time of the year. While photovoltaic systems mainly peak in summer, but heating consumes the most electricity in winter, the fuel cell delivers a continuous amount of electricity all year round. In the event of a power failure, in particular, a fuel cell heating system can continue to supply the house with electricity. In addition, the electricity generated can be fed to an external battery storage device to supply the house with peak power loads before it is fed into the power grid.

While other heating systems such as gas condensing boilers or heat pumps are combined with a solar thermal system, this type of combination does not make sense for a fuel cell. The chemical reaction of the fuel cell is designed for continuous operation with an efficiency of over 90 percent. Frequent short-term operation (even without solar thermal or photovoltaic) means that the stack wears out faster and therefore the life time is shortened. Use with other energy generators must therefore be carefully planned and designed individually for each project. An energy manager to control the various systems is essential to ensure a long lifespan for the fuel cell.

Fuel cell heating: The costs at a glance

Acquisition costs and installation

Fuel cell heating is a comparatively expensive heating with high purchase costs. Depending on the manufacturer and model, the costs for a new system start at around 25, 000 euros and, depending on the size of the system, are roughly open. The shelf life of a stack in single-family homes is currently stated to be at least ten years. As soon as a stack can no longer be used, there are two options:

  1. The stack is replaced by a new one and the system can produce electricity and heat as usual.
  2. There is no renewal of the stack and the fuel cell heating is only used by means of the integrated gas condensing boiler.

Of course, the second option only works if it is a complete system. However, a fuel cell heater is not immediately defective, but can continue to produce heat even if the stack fails. The cost of a new stack is around 5, 000 euros, depending on the type and manufacturer. However, the ongoing costs for fuel cell heating are limited to gas consumption and maintenance costs.

Stack
Stack

Small module with a lot of content.

Photo: Bosch

Compare the efficiency and costs of fuel cell heating with other systems: Overview of heating types 2020: efficiency, costs and funding.

Legal provisions and grants

The type of air-flue gas system can be regulated individually for each federal state in such a way that a fire protection class F30 system is not sufficient, but an F90 system must be used. The responsible district chimney sweep provides precise information. In principle, the fuel cell heating can be installed in-house, but it is recommended that it be carried out by a specialist company. Last but not least, the connection to the gas connection must be made by a specialist company.

At first glance, the acquisition costs seem very high, but high funding amounts are possible for fuel cell heating. The Kreditanstalt für Wiederaufbau (KfW) has provided its own promotional loan for the fuel cell (program 433). The amount to be received depends on two components, the performance class of the system and the total eligible costs: Performance class: Each system receives 5, 700 euros as a basic amount and a further 450 euros for every 100 watts of power started.

Total eligible costs : Each facility receives a maximum of 40 percent of the total eligible costs. These include the installation costs, the maintenance costs of the first ten years for a full maintenance contract and the costs for an accompanying energy expert.

Funding example: A system with a capacity of 1 kilowatt and a total eligible cost of EUR 30, 000 receives the following funding: EUR 5, 700 basic amount + (EUR 450 x 10) = EUR 10, 200.

This program can be supplemented with further KfW funding, for example with loans 151 energy-efficient renovation or 153 energy-efficient construction. Outside of the KfW programs, the fuel cell can receive BAFA funding (Federal Office of Economics and Export Control) in the form of the additional payment for CHP electricity according to the KWKG law (law for the maintenance, modernization and expansion of cogeneration) be combined.

Sandra Hess

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