Polyethylene Wave Energy Device Launched

Wave energy developer Polygen deployed a full-scale device three miles off the Cornwall coast in the U.K. last week.

Volta is a 46-metre long, sub-100kW oscillating surge converter made using high density polyethylene (HDPE). 

Polygen’s newly patented device has been designed to optimize the flexibility and resilience of the material to help reduce concentrated stresses and hence produce an extremely cost effective converter.

The key properties of polyethylene from Polygen’s perspective include its high fatigue resistance, strength, light weight, buoyancy and flexibility. The material is non-corrosive and non-toxi and it has an almost unlimited lifetime underwater.

“After initial invention in 2013, we first focused on lots of hydrodynamic and economical simulations assisted by numerous wave tank testing sessions,” said business development manager, Rob Eavis. “There is no device similar to Volta, so we needed to convince ourselves that it would work well enough to be worth pursuing. With everything still looking positive, this August we installed a 6-flap, full scale device at FaBTest.

“During our time at the FaBTest demonstration site we will be primarily researching the behavior and performance of Volta, especially during the winter storms. We have predicted a number of key behaviors that we would love to monitor on the real device. Next year, assuming everything is still looking positive, we will start concentrating on optimizing the entire system, both with the hydraulic controls and also the primary design,” said Eavis. 

“We know already many ways we can make the design more efficient, and we look forward to building these into our future designs.”

The wave energy device is the first deployed at FabTest since Fred Olsen shipped its Bolt Lifesaver wave energy converter to Hawaii in January.