NetBuoy III


Stage 3

Project Lead

Tension Technology International Ltd

Project Sub-Contractors

Griffon Hoverwork Ltd, Kelvin Hydrodynamics Laboratory - University of Strathclyde, International Centre for Island Technology (Heriot Watt University - ICIT, Orkney Campus), PSG Marine & Logistics Ltd

This project is currently ongoing, and final public reporting is due to be published in Spring 2021. 

For further information on the current status, please contact the Lead Applicant.  


NetBuoy integrates two enabling technologies for cost competitive wave energy – impermeable membranes to manufacture buoyant modules and fibre rope nets to encapsulate the buoyant modules. The net applies distributed restraint loads and agglomerates them back to structural ‘hard’ point(s). This is essential in enabling the use of membrane buoyant modules as they cannot be restrained otherwise.

This combination significantly reduces prime mover mass when compared to a steel; the density of the materials are around one-seventh that of steel and are much more compliant with strain at break of around 15% for the membrane. This compliance means it can locally deform under extreme waves whereas the steel structure must carry excess mass (and therefore cost) to provide the required rigidity to avoid plastic deformation.

The inflatable module affords significant advantages in all phases of the lifecycle. The deflated buoyant pod can be cheaply transported in a shipping container. CAPEX and LCOE calculations at Stage II show very encouraging potential for step-change cost reductions.

The Stage III project will install NetBuoy(s) in the ocean environment to assess the effect of long-term exposure to seawater, environmental loading, biofouling and UV and ozone. This will increase the TRL to 7. Tank testing will be performed that will demonstrate the application to WEC forms other than point absorbers to increase the technical and commercial readiness in this respect.

The long-term vision for the proposed solution is the deployment of large WEC arrays that utilise the NetBuoy for their prime mover water plane, swept volume and buoyancy requirements. The buoyant pods can be manufactured globally in an existing supply chains.