REDUCED MODEL FOR WAVE POWER PLANT LONG-TERM PERFORMANCE ASSESSMENT
R.AuguiJ.de Bettencourt, P. Justino andM. T.Pon tes, INETI-ITE, Departamento
de Energias Renovaveis, Estrada do Paco do Lumiar, 1699 Lisboa Codex, Portugal
ABSTRACT
Although considerable knowledge was already gainedm the numerical modelling of wave power plants, methodologies for their sizing and long-term performance prediction still need improvement. In particular, there is a need both for more experimental data from pilot plants and for simple, yet comprehensive and accurate, design methods. The current paper focus on the latter aspect. It is shown how to devise performance assessment scheme using (i) samples of results of detailed numerical models to build a reduced model and (ii) taking into account the wave climate at a chosen site. A practical example of this scheme of principle is presented for a simplified case of an uncontrolled oscillating water-column plant, and it is demon strated how important conclusions about sensitivity to design parameters and best modes of operation can be derived that are not apparent from the isolated inspection of detailed numerical simulations.
USE OF NUMERICAL WIND-WAVE MODELS FOR ASSESSMENT OF THE OFFSHORE WAVE ENERGY RESOURCE
M. T. Pontes, INETI - ITE, Lisbon, Portugal
S. Barstow, OCEANORS. A., Trondheim, Norway
L. Bertotti & L. Cavaleri, ISDGM, Venice, Italy,
H. Oliveira-Pires, Instituto de Meteorologia, Lisbon, Portugal
ABSTRACT
In the last two decades the performance of numerical wind-wave models has improved considerably. Several models have been routinely producing since the mid 1980 s good quality wave estimates globally.
The verifications of wind-wave models have mainly focused on the evaluation of the error of the significant wave height Hs estimates. However for wave energy purposes the main parameters to be assessed are the wave power Pw and the mean (energy) period Te.Since Pw is proportional to Hs2Teits expected error is much larger than for the single wave parameters.
This paper summarises the intercomparison of two wind-wave models against buoy data in the North Atlantic and the Mediterranean Sea to select the most suitable one for the construction of an Atlas of the wave energy resource in Europe., A full verification in the two basins of the selected model - the WAM model, implemented in the routine operation of the European Centre for Medium-Range Weather Forecasts - was then performed against buoy and satellite altimeter data. It was found that the WAM model accuracy is very good for offshore locations in the North Atlantic. but for the Mediterranean Sea the results are much less accurate probably due to a lower quality of the input wind fields.
