Electricity from the Sea
October 31, 2013
A device that will generate electricity by harnessing the power of sea waves is being developed by scientists at the £ód¼ University of Technology in central Poland. The device will be used to power signaling lights in sea buoys and fishing nets.
The device will contain a set of pendulums that will be set in motion by sea waves. This will power a generator and produce electricity.
Normally signaling lights in sea buoys and nets are powered by batteries, but replacing these is often a tedious and expensive job, says the research team leader, Prof. Tomasz Kapitaniak, head of the Department of Machine Dynamics, part of the £ód¼ university’s Faculty of Mechanical Engineering. But once the signaling light is provided with its own little “power plant” powered by sea waves, he adds, battery replacement will no longer be needed.
According to Kapitaniak, the device designed by the £ód¼ researchers will be more efficient in terms of power generation than solar panels. It will also be able to work at night, even during the long polar night.
The research project has been co-financed by the Foundation for Polish Science. The researchers have developed a model of the device and carried out the first tests in a swimming pool. The next step will be to build a fully-fledged prototype.
There are already devices that use the motion of sea waves to generate electricity, but the invention of the £ód¼ team will be the first to use a pendulum-based synchronization mechanism, according to Kapitaniak. The pendulums will be connected with one another using flat springs. This kind of miniature power plant will power signaling lights on offshore buoys as well as lights on fishing nets, thus helping fishermen locate their equipment at sea, especially at night.
Pendulums moving to the same rhythm and placed next to each other, but set in motion separately, are capable of spontaneous synchronization, Kapitaniak says. For such a synchronization phenomenon to occur, the pendulums must have the same period of vibration and there also needs to be a flow of energy between them.
“One may ask why build such a complicated system if you can use ordinary batteries to power signaling lights,” says Kapitaniak. “The problem is that batteries need to be replaced, which in the case of fishing nets is a tedious and expensive process. Besides, the functioning of our device does not entail any additional costs. This is energy we get for free from the sea. We don’t have to pay for it. Plus our design has another very important advantage—it works at night, on cloudy days, and even during the long polar night. It is therefore better than other known devices powered by solar panels.”
Kapitaniak adds, “We still need to test the system out at sea. We have to build a prototype of the device and test it in real-life conditions. We also need a partner with more experience in marine engineering.”
Kapitaniak says that for the time being the researchers have only carried out a small part of the fundamental and theoretical research that is needed for the project to produce the expected results.
Danuta K. Gruszczyńska