Ocean renewable energy is a promising energy source which has attracted considerable amount of interest in recent years. The oceans have a tremendous amount of energy such as the wave energy, tidal energy, thermal gradient along the ocean depth, salinity gradient, etc and these when harvested can benefit remote coastal locations and the islandic communities where the population density is high and are purely supported today with fossil fuels.
Among the various energy sources, tidal stream energy offers enough confidence as an energy source due to its high predictability. Tidal energy is exhibiting a learning curve similar to the offshore wind energy systems since there are many common technologies between wind turbines and tidal turbines that promotes an inter-industry learning resulting in significant reduction in levelized cost of energy. Presently designs are being evolved into new generations towards new markets such as first generation tidal turbines were being traditionally designed to be sea bed mounted, while in the second generation semi-buoyant and totally floating designs are being pursued with high degree of product modularity and visual impact to counter the environmental impact challenges and minimal operating costs. To confirm designs towards tropical waters that experience low tidal flow conditions and accelerated biofouling and corrosion Energy Research Institute @ Nanyang Technology University does detailed simulations and field level testing. As part of this effort, test bedding was planned to characterize the low flow tidal turbine device and to understand their capacity factor, overall asset cost, operating cost and cost of energy.
In a recent effort, a Tidal In-Stream Energy Demo Project in Singapore was initiated through a university-industry collaboration between Energy Research Institute @ Nanyang Technological University (ERI@N), Envirotek Pte Ltd, OceanPixel Pte. Ltd., Schottel Hydro and Lita Ocean Pte. Ltd. The project showcases the feasibility and viability of such appropriate technologies towards remote coastal energy security needs. It also confirms that Singapore can be a R&D Hub and can support the necessary supply chain needs due to the marine industrial cluster presence to design and develop barges and moorings to support towable tidal turbine barge based system. This project was unique in terms of its turbine self-erection capabilities for easy maintenance. In this demonstration a 50kW Schottel In-Stream Turbine from Schottel Hydro is integrated into a Catamaran Platform build by Lita Ocean Pte Ltd. Technical Expertise and Marine Operations Management Support from Aquatera and Orcades Marine helped in making sure the project was a success. Full deployment video can be found in https://vimeo.com/212361278. ERI@N supported the necessary early studies in hydrodynamics, turbine-site interaction studies, fluid-structure interaction studies necessary for the support structure studies, e.t.c. to evaluate the turbine’s stability and performance during regular operation and tide changeover & extreme conditions.
We hope through such modular systems we can support the remote islands of Southeast Asia which has more than 25,000 islands and can extend to support other small islandic development states (SIDS) in various parts of the world that are generally diesel powered at an energy cost of $0.50 to $0.70/KWh. The present deployment’s techno-economic studies showed tidal energy systems can easily out beat the incumbent fossil based energy price and thus can be a promising clean energy alternative to the remote coastal and island region and ensure its pristine marine ecology.