Published on December 20th, 2018 | by Karel Beckman0
Dutch Innovations Promise Lower Maintenance Costs For Offshore Wind
December 20th, 2018 by Karel Beckman
Two Dutch companies have developed different technologies to simplify the connection of wind turbine components like monopiles and other transition pieces.
Startup company Fistuca, a spin-off of Technical University Eindhoven, recently won the Offshore Wind Innovation Award with its Blue Wedge Connection technology, a maintenance-free wedge construction to connect turbines with monopiles. The Offshore Wind Innovation Award is organized by the Dutch offshore wind community, which includes major companies like Siemens and Van Oord.
According to the jury, the Blue Wedge Connection is faster and cheaper than bolted and grouted connections. In addition, thanks to the symmetrical distribution of forces, the connection is highly scalable and needs no maintenance.
Currently, connections between turbines and monopiles are made with bolts or with grout (concrete). These require frequent re-bolting programs or grout adjustments which lead to high and sometimes unforeseen maintenance costs. The Blue Wedge Connection aims for zero maintenance, reduces installation time, and limits steel use.
Fistuca is not the only company working on new connection technologies. Earlier, in September of this year, a consortium of Dutch companies, called SJOR, installed a new so-called “Slip Joint” connection on a monopile of an existing wind turbine in Eneco’s Prinses Amalia Wind Park off the coast of IJmuiden.
The Slip Joint connection has been developed by DOT, another offshore wind technology company in the town of Delft. Both companies are spinoffs from Delft University of Technology, which has an extensive offshore wind research program and is also home to the Nuon Solar team which has frequently won the World Solar Challenge for solar-powered cars.
According to a press release from the SJOR consortium, the Slip Joint connection “works and looks like two paper cups upside down stacked on top of each other. The connection is based on friction, where the weight ensures a firm and stable connection. Installation is done by simply sliding the wind turbine over the monopile without the use of grout or bolts. This simple mechanism allows for cost reduction in material, equipment and personnel as well as allowing for a shorter installation time.”
According to SJOR, the Slip Joint connection could lead to a cost reduction of between €10 and €20 million per offshore wind farm.
The SJOR project is part of the GROW program, a €100 million R&D program aiming to reduce the costs of offshore wind energy, supported by leading Dutch companies and research institutes, including Shell, Tennet, DNV GL, Eneco and Innogy as well as Delft University of Technology.
The Netherlands has a highly ambitious offshore wind target: according to the “climate accord” agreed upon by government, industry and NGOs in July 2018, the Netherlands is planning to produce 49 TWh of electricity from offshore wind in the North Sea, equal to half of current total Dutch electricity consumption. All of the Dutch offshore wind research and developments are coordinated by the government-supported Top consortium for Knowledge and Innovation (TKI) Offshore Wind.