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Both technologies are under development in Germany, at a partnership of lightweight construction experts from the Fraunhofer Institute for Applied Polymer Research (IAP), BTU Cottbus and an industrial partner. The systems could provide hydrogen for heat and power at home, or fuel for cars.
According to data from the German Environment Agency, private households are responsible for about a quarter of Germany's energy consumption. Half of that energy is obtained from natural gas and crude oil, which needs to be reduced to help tackle climate change.
“Hydrogen obtained from renewable energy has so much more potential as an energy carrier for the future,” said Professor Holger Seidlitz, lightweight construction specialist at BTU Cottbus-Senftenberg and head of polymer and composite research at IAP in Wildau.
The partnership is taking a ‘two-pronged approach’ to the issue – developing a small and efficient wind power plant to provide the energy needed for hydrogen production, and exploring ways of storing the valuable gas. The team is producing new types of tanks made from fibre-reinforced composites.
“The intention is to design the wind turbine small enough to allow private individuals to have a system like this in their garden. The hydrogen will be generated in-situ in a small electrolyser and stored in the tank,” said Prof Seidlitz.
“It can then, for example, drive a fuel cell inside the house that produces heat and power at the same time. And owners of hydrogen-powered cars will, in the future, be able to refuel their vehicle at home. The real key to the concept is that the entire system is designed to be small, yet extremely efficient.”
The lightweight construction experts have devised a new propeller that moves even in a light breeze.
“The wind here in the Lusatia region is much weaker than it is in Northern Germany,” said Marcello Ambrosio, the mechanical engineer overseeing the project at Fraunhofer IAP. “We designed the rotor blades to suit these wind conditions, and reduced their dimensions by around 30% compared to conventional small wind turbines.”
The team used an industrial 3D printer to make a plastic mould for producing the rotors from fibre composite. Lightweight construction specialist EAB Gebäudetechnik Luckau assisted with the process.
Although designed for efficiency in weaker winds, the rotors reportedly withstand stronger winds as well. The blades are designed to yield and bend during storms, rotating out of the wind.
“As a result, the turbine slows down the speed of rotation by itself and escapes any damage,” said Prof Seidlitz. This eliminates the need for complex control technology and elaborate mechanisms in the rotors, which will be tested in the open over the next few months.
Conventional hydrogen tanks for industrial applications consist of two pressure-resistant steel vessels. Lightweight tanks made from carbon fibre composites would be much more convenient for private households and mobile applications, a Fraunhofer announcement said, requiring less material and being easier to handle. The tanks would need to be extremely safe to prevent leaks and explosions.
The storage units being developed are made from carbon fibre strips wound onto a cylindrical body. Impregnated with synthetic resin, the strips harden to form a tank that can withstand many hundreds of bars of pressure. The experts are also integrating sensors into the tanks to detect leaks.
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