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Authors
Advisor(s)
Abstract(s)
O trabalho proposto consiste na caracterização da variabilidade da velocidade média
inter-anual do regime de ventos do território da Polónia, Roménia e Portugal
continental com o objectivo de determinar o período mínimo de medições de vento
locais necessárias à sua caracterização. Para isso, foram analisados e tratados
estatisticamente um conjunto de dados de medições de vento obtidos em estações
anemométricas, instaladas em diferentes zonas do território dos Países em estudo,
durante os últimos anos. Numa segunda fase foram utilizados dados de Reanalysis do
NCEP/NCAR (National Center for Environmental Prediction/National Center for
Atmospheric Research) com o objectivo de verificar se existe uma tradução do
comportamento da variabilidade de longo termo.
Os dados das medições locais de vento indicaram que o desvio máximo da velocidade
média diminui à medida que se incrementam o número de anos usados na sua
determinação. Mostraram também que, em Portugal, foi registada uma menor
variabilidade inter-anual do regime de ventos que nos territórios em estudo na Polónia
e Roménia e que foi na Polónia que se registou maior variabilidade inter-anual.
A utilização dos dados de reanálise correspondentes ao período das medições
efectuadas nos diferentes territórios em estudo mostrou que os dados do NCEP/NCAR
traduziram de forma aceitável a variabilidade inter-anual do regime de ventos medida
nos locais.
Os resultados do estudo da variabilidade inter-anual de longo termo feita, utilizando os
dados de Reanalysis (30 anos de dados do NCEP/NCAR) mostraram que para
Portugal e para o território da Polónia a utilização de dois anos consecutivos é
suficiente para caracterizar o regime de ventos do local tendo-se obtido um desvio
máximo da velocidade média de cerca de 6%. Este desvio pode ser reduzido pelo
incremento do número de anos de dados. Relativamente à Roménia a utilização de
dois anos de dados consecutivos resultou em desvios máximos da velocidade média
superiores, na casa dos 8%. Os resultados indicam que o território em estudo está
sujeito a um regime de ventos com um ciclo de vários anos pelo que, estimativas de
produção de parques eólicos feitas exclusivamente com base em campanhas de
medição locais por períodos usualmente utilizados, 2 a 3 anos, comportam uma maior
incerteza, apenas ultrapassável se for possível correlacionar os dados locais com
estações de medição ou bases de dados (NCEP/NCAR, por exemplo) com períodos
de registos suficientemente longos para obtenção do regime de ventos do longo termo.
The proposed work aims to characterize the variability of inter-annual average speed of the wind from the territory of Poland, Romania and Portuguese mainland in order to determine the minimum local wind measurements for its characterization. In order to achieve this, a set of data obtained from wind measurements at met stations in operation over the past years and installed in different areas of the countries and were analyzed and statistically treated. In a second stage data from the Reanalysis NCEP / NCAR (National Center for Environmental Prediction/National Center for Atmospheric Research) was used with the target of ascertaining whether there is a translation of the behaviour of long-term variability. Data from local wind measurements indicated that the maximum deviation of the average speed decreases when increasing the number of years used in their determination. The results showed a higher inter-annual variability of the wind in the regions studied in Poland and Romania than in Portugal. In addition the obtained results demonstrated the highest inter-annual variability in Poland. The use of reanalysis data for the period of the measurements made in the different territories showed that data from the NCEP / NCAR represent in an acceptable way the inter-annual variability of the wind measurement sites. The results of the study for the long term inter-annual variability using Reanalysis data (30 years of data from the NCEP / NCAR) show that two consecutive years are enough to characterize the local wind regime in Portugal and Poland and obtain a result of the maximum deviation of the average speed of about 6%. This gap can be reduced by increasing the time of years of measurements. With regard to Romania the use of two consecutive years resulted in around 8%, a higher maximum deviation of the average speed than in Portugal and Poland. The results show that the studied area is subject to a wind regime with a course of several years so, for that reason the production estimates for a given wind farm made using exclusively local measurement campaigns for usual periods, 2 to 3 years, have a greater uncertainty only surpassed if possible to correlate the local data with met stations or data bases (NCEP/NCAR, for example) with large enough record periods for the characterization of the long term wind regime.
The proposed work aims to characterize the variability of inter-annual average speed of the wind from the territory of Poland, Romania and Portuguese mainland in order to determine the minimum local wind measurements for its characterization. In order to achieve this, a set of data obtained from wind measurements at met stations in operation over the past years and installed in different areas of the countries and were analyzed and statistically treated. In a second stage data from the Reanalysis NCEP / NCAR (National Center for Environmental Prediction/National Center for Atmospheric Research) was used with the target of ascertaining whether there is a translation of the behaviour of long-term variability. Data from local wind measurements indicated that the maximum deviation of the average speed decreases when increasing the number of years used in their determination. The results showed a higher inter-annual variability of the wind in the regions studied in Poland and Romania than in Portugal. In addition the obtained results demonstrated the highest inter-annual variability in Poland. The use of reanalysis data for the period of the measurements made in the different territories showed that data from the NCEP / NCAR represent in an acceptable way the inter-annual variability of the wind measurement sites. The results of the study for the long term inter-annual variability using Reanalysis data (30 years of data from the NCEP / NCAR) show that two consecutive years are enough to characterize the local wind regime in Portugal and Poland and obtain a result of the maximum deviation of the average speed of about 6%. This gap can be reduced by increasing the time of years of measurements. With regard to Romania the use of two consecutive years resulted in around 8%, a higher maximum deviation of the average speed than in Portugal and Poland. The results show that the studied area is subject to a wind regime with a course of several years so, for that reason the production estimates for a given wind farm made using exclusively local measurement campaigns for usual periods, 2 to 3 years, have a greater uncertainty only surpassed if possible to correlate the local data with met stations or data bases (NCEP/NCAR, for example) with large enough record periods for the characterization of the long term wind regime.
Description
Mestrado em Engenharia Química. Ramo optimização energética na indústria química
Keywords
Variabilidade inter-anual Longo termo NCEP/NCAR
Citation
Publisher
Instituto Politécnico do Porto. Instituto Superior de Engenharia do Porto