Clean thing

"If these capacities were fully exploited to feed in hydrogen, a considerable input of renewable energies could be stored in the overall storage system."

These three strengths are important prerequisites for large-scale deployment. That's why the eight-member team is developing prototypes whose performance and service life are getting higher and higher step by step. One of the obstacles is the ageing phenomena of the cells during long-term operation: At operating temperatures of 600 to 800 degrees Celsius, the structure of the electrodes changes, which directly affects the electrochemical processes. "We want to minimize these effects," explains Bram. He is certain: "We can make an important contribution to the industrial implementation of this technology here.

For the energy system of the future, not only must hydrogen be converted into electricity as efficiently as possible - but also, conversely, the electricity from renewable energy sources that is currently not needed must be converted into hydrogen. "In order to be able to compensate for the fluctuating power generation of renewables, flexible electrolysis plants for the production of hydrogen are becoming increasingly important," says Christopher Hebling, head of the Hydrogen Technologies Division at the Fraunhofer Institute for Solar Energy Systems ISE. The existing natural gas network can be used as a long-term storage facility. Fraunhofer ISE has commissioned a plant on its Freiburg premises that can feed hydrogen into the gas network. Since August 2017, customers of the municipal distribution network have been receiving up to two percent hydrogen in natural gas. Up to ten percent would be technically possible. Behind this, there is enormous potential in Germany: Around 50 natural gas storage facilities (underground) have a capacity of around 23 billion cubic meters of gas. "If these capacities were fully exploited to feed in hydrogen, a considerable input of renewable energies could be stored in the overall system," says Hebling. 

Andreas Friedrich also wants to improve the ecological balance. And that means road traffic. Due to the trend towards online shopping, for example, the number of parcel carriers is growing significantly, the streets in the cities are dense, the air thick. "It gets particularly congested on the 'last mile' from the logistics centre to the customer," says Friedrich, who is Head of the Department of Electrochemical Energy Technology at the Institute of Technical Thermodynamics at the German Aerospace Center (DLR). Together with a team of DLR researchers, he is further developing the cargo bicycle into the delivery van of the future - with the help of a fuel cell module they have named Fuel Cell Range Extender (FCREX). "It will be designed for conditions that correspond to the performance, radius and duration of load wheel operations in city centres," says Friedrich. "The FCREX weighs around seven kilos, the small box can be attached to the bicycle frame." Among other things, precious metal catalytic converters provide the necessary power. In a next step, the researchers want to significantly reduce the proportion of this expensive material. So far, around 20 grams of precious metals have been used in a fuel cell that can power a car. The exhaust system of a diesel engine contains eight to twelve grams, while a petrol engine contains four to six. "We want to achieve these levels gradually," says Friedrich. In 2019, the developments will enter the final phase, and in 2020 trial operation is to start at selected locations. Within a year, the load wheels should initially be able to cover up to 1,000 kilometers - and save correspondingly high CO2 emissions compared to conventional delivery vans.