Progress of Development
There are literally dozens, maybe up to 100, different wave energy devices being developed throughout the world. Hardly any have reached full scale operation. Much of the problem is that most of these devices either float on the surface relatively close to the shore, or are mounted on the sea shore, and are highly prone to storm damage. Neptune eliminates this problem, as it sits 40 M below the surface. It is designed to capture the average long period 3 metre swell that predominates around the western Isles but can be adapted to any wave spectrum.
This novel approach has only one moving part, a conventional low pressure Kaplan turbine and generator. It operates in a wide range of sea states, is not prone to storm damage, is omni-directional, can be fabricated cheaply in reinforced concrete, and creates no visual impact.
Although this concept was invented in the 1970s the modern development of the device only started in 2004 with the formation of Neptune Energy Ltd.
A number of novel changes were made to the original design and a 1:20 scale device was built in fiberglass, and a number of tank testing sessions were conducted firstly at GKN on the Isle of Wight, and latterly at the University of Glasgow. These tests proved conclusively that electricity could be generated.
The device has been tested over a wide range of operating parameters including wave period, wave height, bottom depth, inlet depth, and outlet duct geometry.
The data showed that the device resonates over a wide range of wave periods but more testing is needed to optimise the design, cost and performance of a full scale prototype.
Tank testing is only part of the story and it has been complemented by software modelling to validate and optimise the design. In 2006 the Joule Centre (a partnership of North West Universities and Energy Industries) awarded a £99,000 grant to Manchester Metropolitan University to create a CFD model of Neptune using Star-CCM+ software. This work is ongoing.
Neptune is currently actively seeking partners to further develop the concept and work toward a full scale prototype.