Technology development started in 1999 in cooperation with the Energy Research Foundation ECN and various Dutch engineering companies. In 2008, a technology transfer to Tocardo took place, in participation with the Dutch Technostarter fund E2 Cleantech, for further commercialisation.
An important step for Tocardo was the testing of the first prototype in 2005 and a follow up with a long term demonstration at the same site in 2008. The demonstration turbine is still operational today. Since 2008, many tests have been performed including open water tests at sea and various component tests.
1999-2005: Research and testing of different design concepts for a horizontal axis design turbine (Venturi/Ring generator). A turbine with a Venturi duct was tested using a floating platform. Both the Venturi design and the ring generator design proved less economical than a two-blade centre based direct drive generator design. Tocardo decided to continue with development and testing of a two-bladed horizontal axis turbine with a centre based generator towards a commercial series production.
Good performance results
2005-2008: Prototype testing of a full scale 30 – 50kWp two-bladed uni-directional turbine with off-the shelf available standard gearbox and asynchronous generator. Performance and environmental impact tests were performed at the Afsluitdijk tidal discharge sluice test location of Tocardo in the Netherlands. The turbine showed good performance results with the two-bladed rotor design and chosen power system. Fish monitoring surveys showed no negative impact on fish. Tocardo decided to replace this PTO set-up and develop a commercial demonstrator turbine with a permanent magnet direct drive PTO. The robustness and zero-maintenance performance of a direct drive generator made it a much better solution for offshore tidal turbine application.
2008: Tocardo becomes an independent company, separated from Teamwork Technology B.V.
2008-2012: Design and testing of a full scale commercial demonstrator of the T1 turbine with a maximum power output of around 100kW. Since 2008 this demonstrator is operational at the Afsluitdijk tidal discharge sluice test location. This turbine is grid connected. First a fixed pitch uni-directional blade rotor was tested and secondly a patented bi-directional fixed pitch blade rotor was tested. This system is fully passive and a zero-maintenance design. The bi-blade design makes it possible to turn the two blades simultaneously 180 degrees for reverse flow operation. The bi-blade mechanical performance and robustness has tested since 2011. In 2012 open water tests were performed with the T1 demonstrator. The bi-blade hydrodynamic design was improved for the productions series model. This demonstration turbine provided proof of product and formed the blue-print for the commercial production series design.