“Subhub was conceived for utility scale tidal turbine deployments but is equally beneficial for industrial and community scales”
Subhub has been demonstrated at the community scale. However, there are designs for both industrial and utility scales and at each stage their are specific technology steps that are required to provide further step changes in the CAPEX and OPEX and enhancement of yield.
Community Version (Gen-01, 150kW <>300kW)
This is simplest version of the Subhub with rigid leg and monocoque design. The outer shell is takes the hydrostatic pressure load and this makes the hull form relatively expensive to produce.
The wave and tidal load on this structure is relatively high which means the ballast ratio is high hence every bit of buoyancy is required
Industrial Version (Gen-02, 300kW <>1MW)
The version is at least double the size of the Community version and experience similar tidal and wave loading and hence the ballast ratio drops significantly.
Also, being physically larger turbines, it requires deeper water hence they hydrostatic loads become more significant. As a result of both these factors, this version integrates a transition to the use of cylindrical ballast tanks which can be standardised and are quickly and easily produced at relatively low cost. This reduces the relative CAPEX of the structure significantly.
Utility Version (Gen-03, 1MW<>2MW+)
The utility version of the Subhub comes in a 2 parts:
- Seabed template which holds the main ballast and buoyancy to recover that ballast;