WWT tidal vessel could prove a viable option for off-grid sites

The Water Wall Turbine (WWT) tidal vessel demonstration project has resulted in the development of 3 major sub-systems which combined could prove a viable solution for powering many remote communities around the world.

WWT installed its 1MW turbine driving a 500kW power plant, coupled with the proprietary micro-grid management system and the energy storage system, at Dent Island Lodge, located in Canadian province of British Columbia last year.

The project has met all its original objectives, according to WWT, by developing a commercially viable tidal energy system suitable for narrow, shallow channels and river streams, and micro-grid management system with advanced energy storage for remote and distributed generation.

WWT’s floating tidal turbine consists of an anchored 550-tonne catamaran-like barge that houses a large 72-tonne paddle wheel turbine.

It rotates at less than 12 revolutions per minute, and is designed using WWT’s patented technology that extracts not just the kinetic energy, but also the latent potential energy of fast moving currents by operating on the surface where currents are strongest, according to Natural Resources Canada (NRCan).

A remote ‘islanded’ micro-grid system was designed and developed to enable Dent Island to manage tidal generation, 500kWh energy storage and emergency back-up diesel.

Micro-grid management uses energy storage to provide continuous power during slack tidal periods and facilitates the integration of multiple sources of power to provide for peak periods.

A custom interface was developed between WWT’s micro-grid management system and Tesla’s energy storage management system, as well as a specialty on-vessel current converter, according to NRCan. The micro-grid and energy storage systems were installed on Dent Island.

Additional achievements of the demonstration project include the design and installation of the unique mooring and anchoring system to keep the turbine at station under the tremendous bi-directional currents, NRCan said.

Also, net power production was delivered with limited turbine blades submersion during the initial testing, according to NRCan, along with off-grid control of frequency synchronization and load-following firm power from renewable generation devices that are both variable and intermittent.

“The multiple sources of power generation operating through a micro-grid and energy storage system are key to supplying reliable, firm power to remote communities, particularly in remote northern communities with extreme seasonal variation,” WWT said in its outreach report.

“The newly commissioned tidal turbine, complete with micro-grid and energy storage, provides a showcase for the commercial development of tidal energy. The technologies developed and tested will advance the use and adoption of tidal energy in Canada and around the world,” NRCan said.

Full testing and monitoring of the system at Dent Island will resume June to September 2017, during lodge’s operating season, according to NRCan.

Data collected will be used to improve subsequent design iterations of WWT’s system.

The project is collaboration with Dent Island Lodge, the Natural Resources Canada’s Clean Energy Fund, and Headwate Foundation.