The Helical Twist Vawt design of Quiet Revolution borrowed from Gorlov’s effective “in tube/pipe” water turbine proves not to work to advertised wind tunnel generated performance specifications ( also a tube of controlled flow). Go figure.
The Gorlov helical twist 3 blade VAWT design of Quiet Revolution suffers from poor startup and poor performance in semi turbulent wind and requires an expensive mechanical brake to control top rotational speed to avoid overspeed a genset burnout. Coupled with poor siting advice to get the sale it’s no small wonder the RWE project in Germany failed. The is no chance with this design to ever compete on LCOE terms with current market leaders as serious small wind turbine so it is really a functional art statement “oh look we are doing green energy” dreamed up by marketing wonks.
The question really is did RWE do this deliberately to maintain status quo, as both Ropatec of Italy and Future Tec of Austria Vawts prove to work just if sited properly as advertised and RWE could have easily visited their reference sites to validate field performance.
One can only wonder given all the smart engineers at RWE.
The lesson learned here is wind tunnel testing is only good for hi wind stress testing of wind turbines to determine the turbine structural codependent design parameters needed for material strength, and design telemetry and geometry. Wind Tunnel testing otherwise is not accurate for determining performance of small wind turbines.
Otherwise, real portable field testing of small wind turbines at low mount heights in semi turbulent wind site settings like we did with Starwind5 is the only way to achieve a new VAWT design with a bankable LCOE “Levelized Cost of Energy”.