The proposed R&D project is planned to start 1.1.2007 and end 31.12.2008 with a total budget of 7 500 000 NOK to develop and test a hydrostatic drive for offshore wind turbines and tidal turbines.
The main goal of this R&D project is to increase the stab ility and performance of an offshore wind turbine or tidal turbine with a hydrostatic drive that has a comparable costs, efficiency and reliability.
A hydrostatic drive will be able to replace the conventional drive solutions used today consisting of eit her an expensive and heavy direct driven generator or a vulnerable gear-box solution and reduce the weight in the nacelle with approximately 50%.
NTNU has developed a patent pending control system for such a hydrostatic drive with unique benefits.
Hydr o, Hammerfest Strøm, Statkraft, Shell, NTE and Trønder Energi are partners to evaluate a hydrostatic drive in their concepts.
From the point of view from Hydro the most critical factors that needs to be verified for a hydrostatic drive is:
Will the w eight of components in the top of the 5 MW wind turbine tower (nacelle) be reduced to less than 200 ton?
Is the overall cost for production of electricity (kW/h) competitive with conventional solutions?
Will the hydrostatic drive proposed by NTNU give t he additional benefits due to optimal drive based on input from changing wind speeds?
Is the consortium able to develop such a hydrostatic drive with the overall performance of the control system developed at NTNU with the predicted theoretical performan ce?
Hägglunds and Bosch Rexroth, are currently building and testing a 300 kW hydrostatic drive together with NTNU at the NSB diagnostic station at Marienborg.
The hydrostatic drive will be tested in a wind turbine the period May 2007 until March 2008.
The use of a hydrostatic drive requires development of a suited control system. This will resemble characteristics of a variable speed wind turbine control system but must be adapted.