Low-temperature fuel cells

Direct generation of electrical energy from hydrogen

Reducing the emission of CO2, nitrogen oxides and particulates is one of the key challenges for future mobility. Using hydrogen as an energy source instead of conventional, carbon-based fuels for mobility, heating and industry holds the potential to achieve emission-free power generation.

A hydrogen-based economy in Germany or even in the whole of Europe could be primarily based on renewable energy, while using the converted natural gas network as the distribution infrastructure. In addition to improving air quality and quality of life, hydrogen technology can also stabilise the output variations in power networks that result from the inherent fluctuations of wind and solar energy. Electrolysers can be used to convert highly dynamic, fluctuating power generation into hydrogen, while fuel cells can generate electricity from hydrogen when required.

Due to their compact size and comparatively low weight, low-temperature fuel cells primarily have applications in the mobility sector, whether for private transport, public transport, ‘last mile’ delivery services or niche applications such as airport apron transport – they can be used wherever the accumulation of emissions from fossil fuels has a signifcant impact on air quality. For stationary applications in buildings and homes, there are other, ceramic-based technologies that also provide hot water in addition to clean electrical energy through combined heat and power.

Does hydrogen present any dangers? When combined with oxygen or air, hydrogen can form an explosive mixture called oxyhydrogen. However, the refuelling process works in a similar way to that used for liquefed-gas
powered vehicles, thus eliminating any chance of oxyhydrogen forming. Modern hydrogen tanks are made from high-strength carbon-fbre composite material that can withstand a truck driving over them or being shot with a frearm.

The DLR Institute of Engineering Thermodynamics, which is part of an international network, is researching low-temperature fuel cells, starting with the materials themselves through to manufacturing technology, analytics and management, and fnally the fnished system.

German Aerospace Center (DLR)
Kaspar Andreas Friedrich E-Mail: andreas.friedrich@dlr.de · DLR.de/en