The aim of the partnership is to conduct testing of fuel cells, which experts consider one of the key technologies of the future. The Ettlingen project is part of an EnBW fuel cell program for the supply of residential energy that is being conducted throughout the state of Baden-Württemberg. And fuel cells are also a focus of EnBW’s research and development activities. Since late 2001, EnBW has been actively supporting the development of fuel cells, with the goal of bringing the technology to the market launch stage. Thanks to the cooperation with the fuel cell manufacturers, the company is gaining even more experience with the use of fuel cells in everyday practice. This knowledge is leading to further improvements in fuel cell systems technology, a better energy balance, and greater environmental compatibility — while also bringing decentralized fuel cells a step closer to efficient operation. "Those who intend to be using efficient, environmentally friendly technologies in the future must invest their energy in ideas and in supporting this cause today. EnBW sees itself as a source of momentum on the market. And on the basis of users’ experience with everyday applications of this technology, we intend to actively support its ongoing development and thus the market launch of fuel cell systems," explains Uwe Schöneberg, managing director of EnBW Vertriebs- und Servicegesellschaft mbH.

By virtue of their high efficiency and low pollutant emissions, fuel cells are an energy source that helps to preserve the environment. "Thanks to their outstanding energy efficiency, fuel cells are especially well-suited for supplying energy for residential use. In addition to the environmental aspect, the important thing for us as a local utility company is to build up technological expertise early on, especially because some interesting opportunities will be opening up in the fuel cell sector," says Eberhard Oehler, managing director of Stadtwerke Ettlingen.

But the project managers aren’t only delighted with the technological integration of the fuel cell into the existing heating system. The construction techniques used to link the fuel cell to the system also won high praise: An attractive addition was specially built for the fuel cell. This is advantageous because the fuel cell will be plainly visible to the public, instead of being hidden from sight in a basement area.

The prototype unit that has been put into operation — a EURO 2 from Vaillant — is a PEM low-temperature fuel cell heating system. The fuel cell runs on natural gas, which is pre-processed into a hydrogen-rich gas in an integrated reformer. The chemically bonded energy is then immediately converted into electricity, and without further conversion steps. In addition to the electricity the system delivers, heat and pure water as a by-product are simultaneously produced from the hydrogen rich fuel and the oxygen from the atmosphere. The fuel cell delivers a maximum of 4.5 kilowatts of electrical output and 9.1 kilowatts of thermal output. It has an electrical efficiency of approximately 30 percent and an overall efficiency of roughly 85 percent.

The fuel cell heating unit in the nursing home is being operated as part of a contracting deal. This operating concept is beneficial for the senior citizen’s home: Caritas only has to pay for the energy it actually uses, while the project partners Stadtwerke Ettlingen and EnBW are responsible not only for installing the heating unit but also for its operation and maintenance. EnBW retains ownership of the fuel cell system.