Imagine being able to use your garden as a secondary energy source?
It seems that our smart homes are getting even more brilliant.
Data obtained by the German Environment Agency indicates that private homes are now responsible for about 25% of Germany’s total energy consumption. And almost half of this energy is collected from natural gas and crude oil. This statistic is sobering when you consider climate change.
A need for hydrogen power
“Hydrogen obtained from renewable energies has so much more potential as an energy carrier for the future,” stated Prof. Holger Seidlitz, who is a lightweight construction specialist at BTU Cottbus-Senftenberg. Additionally, he’s the Head of Polymer Materials and Composite PYCO research from the Fraunhofer Institute for Applied Polymer Research at its Wildau location.
Seidlitz and the research team are using a dual approach to using hydrogen in the future. First, they are focusing on energy sources that are needed for hydrogen production. Their co-op partners are creating a small, efficient wind power plant for this. Secondly, they are searching for ways of storing this valuable gas. For this, they are developing new kinds of hydrogen tanks that comprise fiber-reinforced composites.
Hydrogen for fuel cells and vehicles
“The intention is to design the wind turbine small enough to allow private individuals to have a system like this in their garden,” explains Holger Seidlitz. “The hydrogen will be generated in-situ in a small electrolyzer and stored in the tank. 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 vehicles at home. The real key to the concept is that the entire system is designed to be small, yet extremely efficient.”
Beginning with a wind turbine, these lightweight construction experts will devise a new kind of propeller that reacts to the lightest of breezes.
“The wind here in the Lusatia region is much weaker than it is in Northern Germany,” explains 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 percent compared to conventional small wind turbines.”
Fraunhofer also acquired an industrial 3D printer that can create objects they need for the project. Marcello Ambrosio and his colleagues used this 3D technology to fashion a plastic mold to produce rotors that can react to weak winds.
Lightweight and agile rotors
These fiber-reinforced materials are made by precisely inserting fiber strips in a mold and subsequently hardening them using either resin or an alternative synthetic material to form the needed component. These strips are usually placed manually.
But at Fraunhofer IAP, this task is performed by a modernized and automated fiber placement machine that will precisely position the fibers within the mold.
Ambrosio reasoned, “The difference between this system and manual placement is that there are fewer overlaps, which allows us to significantly reduce the dimensions.”
Although made for greater efficiency in weak winds, the rotors can withstand strong winds too. The rotor blades have been designed to resist and bend during storms and rotate out of the wind.
“As a result, the turbine slows down the speed of rotation by itself and escapes any damage,” says Seidlitz.
This will eliminate the need for any complicated control technology and elaborate mechanical systems. The rotors are going to be tested in the upcoming months. It is believed that they will demonstrate their efficiency over conventional wind turbines.
Tank with built-in safety sensors
As stated earlier, their second project pertains to creating lightweight construction technology for producing a hydrogen tank. Standard hydrogen tanks within industrial settings generally have two pressure-resistant steel vessels.
If used in the gardens of thousands of private homes, a lightweight tank will be needed. Its carbon fiber composites would have to have much less material and be even simpler to handle. And in addition, they must be very safe to use.
Because hydrogen can create a very explosive mixture when mixed with atmospheric oxygen, it cannot be permitted to escape. The Lusatia team proposed an exciting solution for this.
Since these tanks are constructed from carbon fiber strips that are wound on a cylindrical body, they could be impregnated with synthetic resin. Then the strips could be hardened to form tanks capable of withstanding several hundreds of bars of pressure. The experts also plan to integrate sensors into the tank design for detecting any leaks.
“We are currently using 3D printers that are able to process electrically conductive dyes,” points out Marcello Ambrosio. “We work these dyes directly into the fiber composite.”
The researchers could even insert tiny electronic components directly into the walls of the tanks. These early warning systems are very vital in creating safe use for future customers.
Holger Seidlitz further emphasizes that all the research cooperation is an incredible boost for the entire region. “Lusatia is highly influenced by the structural transformation. Coming from this region, I feel it’s important to integrate small and medium-sized enterprises into our research projects to establish continuous value creation chains.”
With the creation of these wind turbines and associated tanks, they combine two major components—renewable energies and hydrogen technology—and both of them will be vital in the upcoming years.