The SWIP Project is a pan-European initiative to research and develop small and medium size wind turbines in urban and semi-urban environments. It receives EU funding and involves a number of companies and academic institutions within Europe, but is also coming to an end in September 2017. Since its inception in 2013, what has it managed to achieve?
Three demo sites were established, in Spain and Poland. These featured a 20kW installation in an industrial district of Gdansk, a sub-3kW vertical axis turbine in a domestic setting of Choczewo, and a 4kW horizontal turbine on a university campus in Spain's Zaragoza.
The analysis of wind profiles in urban environments is very important, so that the effect of fixed structures (eg, buildings) and moving structures (eg, lorries, cars) is understood. The project would aim to improve blade design to improve efficiency, reduce noise and increase generator longevity.
The project has managed to improve the methodology for wind resource analysis, using thermal stability and thermal stratification, implemented in Meteodyn and Urbawind software applications.
The blades of a conventional wind turbine are key trouble-makers in an urban environment. They can affect the turbine's response to the urban wind profile featuring turbulence, gusts and low wind speeds - plus vertical wind direction - so are a priority feature of the project.
Blade design has been optimised using Computational fluid dynamics (CFD) analysis, with wind tunnel testing to verify performance. They have updated tip designs, and are wider that on other small-size wind turbines, helping to reduce vibrations (and noise) and improve aerodymanics.
Other wind turbine components were analysed: gearbox; converters; controls; masts; anchorage.
Three new designs of generator have been developed, constructed and tested at the demo sites. These feature segmented stators, a better magnetization technique and an initiative to make generators more modular in construction. A major focus was to reduce jerkiness at low speeds, known as cogging torque, and the outcome was a generator that works quieter, more reliably and at lower wind speeds. The generators have also halved in weight, which brings obvious cost-saving opportunities to the turbine mast and anchorage. Electrical converters have also been developed, and this could all add up to efficiency improvements of around 20%.
Remote monitoring of turbines has been developed, using the Supervisory Control And Data Acquisition (SCADA) system, to check weather conditions and wind turbine performance.
New methods of anchorage have been developed, specifically optimised for use on the demo sites.