Skip to main content

Identification of variables for site calibration and power curve assessment in complex terrain

Objective



Objectives of the project
The objective of this project is to define the set of parameters which are of importance for site calibration and power curve identification in complex terrain as compared to the parameters important for in the case of the flat terrain. In this way it will contribute to the definition of a more accurate method for the determination or verification of the power curves of turbines situated in complex terrain and will contribute to the improvement of the economics of wind energy projects. The work will cover the cases of individual turbines.
Research approach and methodology
Two nominally identical stall regulated wind turbines which will be installed correspondingly in complex and flat terrain locations are chosen. Prior to the installation of the turbines, site calibration measurements are initiated at the corresponding locations using reference masts and temporary masts in the locations where the w/t will be erected . The general procedure is the same as described in the IEC document but the set of recorded parameters is much more comprehensive. The set of parameters recorded is the same for the two terrain types. After the end of the site calibration the temporary masts are removed, the two nominally identical turbines are installed and the power curve measurements commence. The recorded parameter set is the same for the two terrain types and more comprehensive than the one described in the IEC document. To investigate whether the parameters influencing the power curve are manufacturer-dependent (due to differences in the control system, the drive train or the rotor), the above steps are repeated for one more stall regulated turbine and for a wind turbine of different concept (variable speed, pitch regulated).
To confirm that the results from the measurement campaigns do not depend on the anemometers used, the response of the types of the cup anemometers used in the project are inter-compared under flat and complex terrain conditions. Commonly accepted installation and measurement procedures are agreed for all the measurement campaigns of the project to ensure results that can be compared.
Expected achievements and exploitation
The proposed work is important to the manufacturers, the power plant developers, the financial institutions and the end users. This is justified from the expected results which will contribute to the removal of a considerable part of the uncertainty associated with the production of wind turbine in complex terrain. This uncertainty is the major obstacle for the financing of many wind energy projects simply because the financial institutions do not wish to get involved to potentially high risk investments. Assuming a "worst-case scenario", the big uncertainty becomes an obstacle since the expected profit becomes marginal and the risk for losses substantial. For the manufacturers which must warranty an annual energy production the lack of objective ways to measure or predict the expected power curve in complex terrain can lead to losses or disputes with the wind plant owner. Finally for the potential investor lower uncertainty makes the investment both cheaper and easier to sell further.
The following results will be available for exploitation:
A recommendation of a practicable methodology to replace the existing one for the use in complex terrain
The use of the results for the adoption of an international standard A method for site calibration of immediate use by the wind turbine industry or the windfarm developers
A method for the verification of the power curve by using the nacelle cup anemometer
The results will be readily accessible by the whole of the wind turbine industry. The project results are expected to increase the competitiveness of the wind turbines as they offer better contractual terms due to lesser uncertainty in the investment.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

RISOE NATIONAL LABORATORY
Address
399,Frederiksborgvej 399
4000 Roskilde
Denmark

Participants (6)

Bonus Energy A/S
Denmark
Address
4,Fabriksvej
7330 Brande
CENTRE FOR RENEWABLE ENERGY SOURCES
Greece
Address
Marathonos Avenue, Km. 19
19009 Raphina (Pikeermi)
Deutsches Windenergie-Institut GmbH
Germany
Address
96,Ebertstrasse 96
26382 Wilhelmshaven
ENERGY RESEARCH CENTRE OF THE NETHERLANDS
Netherlands
Address
3,Westerduinweg 3
1755 LE Petten
NEG MICON A/S
Denmark
Address
21,Alsvej 21
8900 Randers
WINDTEST KAISER-WILHELM-KOOG GMBH
Germany
Address
Sommerdeich 14 B
Kaiser-wilhelm-koog