Can wave energy be stored

The generation of wave and tidal energy are important processes when it comes to generating renewable energy. In order to guarantee a constant supply of energy, however, these must work reliably, be inexpensive to install and also be able to withstand violent storms. The irrepressible power of nature often gets in the way of these goals, which is why some exciting innovations have already been worked out, e.g. underwater planes with turbines or a huge tidal power station off the Welsh coast.

A team of engineers from the University of Edinburgh is of the opinion that a dielectric elastomer generator, or DEG for short, could be the solution for installing systems at sea “inexpensively, in large numbers and with little maintenance”. The concept of the DE generator is not new, but the implementation of a laboratory project into a practical device always presents the designers with new challenges, depending on the environmental conditions.

The engineers at the University of Edinburgh worked with researchers from Italy to test their DE generator in a simulated marine environment. This video shows the device in action:

The device is located in a vertical tube, the top of which is enclosed by a highly flexible membrane. A sophisticated water inlet enables water to be pumped into the pipe through the movement of the waves. The air in the tube is set in motion and inflates the membrane at the top. The resulting pressure generates a voltage that can be used to generate electricity. The advantage: There is no need to drive turbines and other moving parts, which require regular and expensive maintenance even in near-shore applications.

Will it work?

The project is still in the laboratory stage. The so-called FloWave tank system of the University of Edinburgh, which has a diameter of 25 meters, was used to simulate a marine environment. But the results, published in the journal Proceedings of the Royal Society, are very promising: the research team believes that a single, scaled device can generate 500 kilowatts of electricity - enough to supply around 100 households. Another advantage of the DE generator is that the permanently installed construction means a low risk for marine life or habitats.

Professor David Ingram of the University of Edinburgh's School of Engineering, who was involved in the study, said: “Wave energy off the Scottish coast is a valuable resource. Developing systems that use them could play an important role in generating clean energy for future generations. "

The biggest problem facing the researchers is the search for a durable, high-quality, interference-free membrane that can withstand the forces of the sea over the long term. But even the most resilient material wears out over time under load. Therefore, according to the study, the main question is how the membranes can be exchanged inexpensively or whether special, long-lasting materials should be used as an alternative. Here in particular, the DE generator has an advantage over corrosion-sensitive devices that are currently being tested in Great Britain and around the world. The way from the laboratory to supplying the grid with electricity is long and rocky, but in principle feasible. In any case, construction is a promising option when it comes to replacing fossil fuels with clean renewable energies.

Incidentally, the construction of the DE generator is similar to the Bombora wave generator that we have already presented at RESET.

This article is a translation by Thorge Jans. The original first appeared on our English language site.