Realising more efficient water turbines
Water turbines have been powering our homes with clean electricity for decades but much of their power and energy is being lost in the process. The EU-funded project 'Enabling renewable energy SMEs to develop submersible and cost-effective vertical axis turbines for energy exploitation in ultra low-head streams' (Water Wing Power) designed more efficient technology to make electricity from water. The project investigated the latest knowledge in the field. With hopes of reaching the theoretical maximum turbine efficiency of 59 %, project partners worked on a cost-effective vertical axis hydro power turbine that exploits 90 % of kinetic energy in rivers. Efforts were directed at realising an optimal hydrodynamic foil design and upgraded mechanical technology, as well as a self-optimising pitch control system. Water Wing Power then integrated the technology into a unified system and conducted tests to validate industrial applications. In the final stages of the project a prototype turbine with a rotor diameter of 1.5 m and a depth of 2 m was designed, built and tested successfully. The prototype even produced electricity that was distributed through the public grid. The turbine operated at 47 % efficiency, out of the targeted 53 %, keeping in mind the maximum turbine efficiency of 59 %. This amounted to 80 % of kinetic energy, much closer to the projected 90 % than current technology. While more refinements are needed on the self-optimising control system, the technology developed proved to be highly competitive, representing arguably the highest hydrodynamic efficiency and cost effectiveness available in the market. The groundwork has been laid to exploit the technology and market it on an industrial scale.