Creating energy from ocean waves is still a big challenge. Despite emerging technologies in the area, there is not any commercially viable solution. The existing solutions have challenges such as substantial amounts of costs on structure, grid connection, deployment and also mooring.
A UK company has developed a concept to overcome these challenges and suggests huge potential for reliable energy output from ocean waves, when it is proved. Despite the fact that the UK company’s concept is a combination of pre-existing technologies, it has two different patents pending for the underlying technology. It depends on a floating ferro concrete platform/vessel to mount an array of wave piston devices, which includes nodding beams together with linear motors to harness the energy from the waves. It can be described as an innovative combination of well proven technologies. It applies stable and rugged Brunelian design principals to create a utility scale, high yielding, direct drive, wave energy capturing device, with few moving parts and long life expectancy.
The technology uses a platform that is an array of floats in contact with the ocean’s surface, mounted onto a large, extremely durable and stable concrete vessel. The energy of the waves is captured by the floats being pushed upwards by each passing wave. This energy via a pivoted beam, is fed directly into a linear motor and allows direct and simple power take off from the sea. The capability to create scale is key. By building multiple platforms, utility scale power off-take from ocean waves can be achieved.
The design uses point absorber wave energy converter technology in the form of nodding beams attached to the surface of a free floating ferro concrete hull. The floats (point absorbers) capture the waves motion, which via the nodding beams, drives the linear generators sunk in the hull decking, to create electricity.
Wave pistons harness energy directly from waves via linear generators, removing any system losses and additional complexity associated with hydraulic systems. Hydraulic is the current best in market power off-take system for point absorbers. The stable platform design allows multi megawatt scale arrays to be deployed individually, which can link via ocean floor connections to other platforms to create utility scale power generation from the world’s oceans. Each platform array lends itself to providing continuous power from source with its magnitude dependant on the energy within the waves at any given time. This is done by blending the outputs of the multiple point absorbers (wave pistons) using power electronics and if needed using short term on board power storage banks such as high powered capacitors. The pre-stressed ferro-concrete floating platform technology is also relatively cheap and durable. The vessel design means it has a very high relative metacentre height, meaning greater stability for power off take.
UK company’s concept is compliant with major requirements in energy industry and promises multi megawatt level energy, if deployment and design is done according to their concept. For the first installation, they plan to use 60 floats, each with a rated power of 80 kilowatts extracted via two linear generators. Examples of same size and type have a proven life span of 75 years and not had a one penny spent on them to date.
So far, the company had all pre-testing works for the verification of the concept and they are seeking to move this to a next level with self-financing partners, who could contribute to demonstration of the technology with a simulation study over a research or technical cooperation agreement. Ideal partners should have expertise in marine technology and offshore structures.
UK company also looks for investors over financial agreement and is open to form joint ventures with energy sector companies for pilot works in the sea environment.