Technology

Most of the existing tidal current energy systems that have been deployed to date are single turbines designed to rest on the seabed. The single turbine approach leads to enormous machines. Besides the high capital expenses for these huge machines, the operating expenses are significantly driven by the necessity to transport the devices to a maintenance base, requiring heavy gear, expensive vessels and suitable onshore infrastructure.
BRTP is directly addressing these cost drivers with a unique approach that combines the innovative TRITON platform developed by TidalStream, which is semi-submerged, floating and freely rotates to the flow, with inexpensive small and robust SCHOTTEL Instream Turbines (SITs).
The electrical power produced by the individual turbines is collected and conditioned in the electrical room located inside the platform system. Hence, the power electrics and control systems are easily accessible for maintenance. Grid compliant electric energy is transferred by cable from the floating structure. Additional conditioning of the electrical energy on shore is not required.

A gravity base foundation is used to anchor the platform system and lowered down to the seabed prior to the final installation. The whole structure is assembled at shore and then towed out to the installation location. The tether arm is lowered down to the foundation and then only the cable connection is required for installation The floating structure is then ballasted into the operating position. Decommissioning of the device occurs  in the reverse order.

TRITON S40 supports 40 lightweight horizontal axis SITs and related electrical power conversion equipment for the autonomous production of 2.5MW of electrical power in high tidal flow velocities.

Two vertical spar buoys are connected by 4 crossarms to create a floating structure that looks like a catamaran on its end.

The turbines are connected in a grid pattern across the crossarms and the entire structure is tethered to a foundation with 2 rigid arms that attach to each of the spar buoys and meet at a subsea hinge that allows pitching, rolling and self-alignment to the flow direction by passive yawing.

Electrical power produced by each turbine is collected and conditioned in the electrical room located in one of the spar buoys. Grid compliant electric energy is transferred from the floating structure to a slip ring unit at the subsea hinge and then to a dry mate subsea connector that connects the device to the grid via a subsea cable.

The floating structure will pivot between operating mode and maintenance/towout mode by ballasting/de-ballasting with seawater as demonstrated over the past 50 years by the RV Flip vessel.
In operating mode access to the electrical system is possible because the spar buoys pierce the surface. In maintenance/tow out mode the structure looks like a catamaran and provides full access to the turbines.