氣候變遷對台灣西部離岸風能潛勢 與發電量之影響評估

Abstract

自工業革命以來，人類大量使用化石燃料，產生大量溫室氣體，造成全球溫室效應，進而導致氣候異常變異。且近年來發生的石油危機，迫使人們轉而開發汙染較低的再生能源取代化石燃料。有鑒於此，各國目前致力於開發再生能源，因台灣位處季風交替位置，風力資源充沛，近年來在風力資源的開發已有快速的成長。 目前在風力發電產業面臨兩大困境，一是由於台灣本島地狹人稠特性，使陸域風力資源開發受到限制，二是全球溫室效應增強，氣候變遷現象影響風能潛勢。據國內研究指出，台灣西部離岸區域為風能最佳位置，我國經濟部能源局也致力於開發離岸風能，因此本研究使用跨政府氣候變化委員會公布之全球環流模式，評估氣候變遷對台灣西部離岸風能潛勢與發電量之影響。 研究分為兩個層次，首先為了解決全球環流模式空間網格太大的問題，使用統計降尺度之多變數線性迴歸方法，以韋伯風速機率分佈推估台灣西部離岸之風能，建立空間解析度5公里×5公里之風能分佈圖。其次再針對風能較高區域以不同裝置容量離岸風力發電機之標準性能曲線推估其發電量，並探討該區域在氣候變遷影響下，未來90年發電量之變化。 研究結果發現新竹、苗栗、台中外海為風能較佳位置，發電量在離岸距離10公里範圍內，以新竹外海之發電量推估最高，而結果也顯示隨離岸距離越遠發電量越大；同時研究結果也顯示3MW之風機較適合西部離岸風能開發。此外，台灣西部離岸未來整體風力發電量可能因為氣候變遷影響東北季風減弱，造成整體發電量略為減少的趨勢。

Ever since Industrial Revolution, fossil fuel has been overly used and greenhouse gas produced subsequently led to global warming and climate change. Also, due to recent global oil crisis, developing alternative renewable energy becomes important among nations. Surrounded by water, Taiwan has plenty of wind energy andrecently has a growth spurt on the development of wind resources. However, there are two limitations for the development of wind industry in Taiwan: the confined yet densely populated land and the growing of greenhouse effect. Taiwan’s west coast has been considered the best location for wind energy development, where Bureau of energy, Ministry of Economic Affairs has been endeavored to offshore wind output. This study uses GCMs published by IPCC to see how climate change might affect wind energy and energy output on offshore on the west coast. Multi-Variable Regression and Weibull wind speed probability distribution were firstly applied to estimate wind energy and to establish a spatial wind atlas in 5km×5km resolution, so as to avoid potential mistake caused by stretched grid within Global Circulation Model. Secondly the nominal performance curve of WECS at rated power was implemented to estimate the energy output for 90 years from now. As a result, wind energy on the offshore of Hsinchu, Miaoli and Taichung appears to be higher. Hsinchu has the highest energy output, and the energy output will increase evidently by the distance offshore in 30km.The result also suggests that WECS at 3.0MW is better implemented in this area. To conclude, wind output in Taiwan might be shortened in the near future due to a weakened northeast monsoon caused by climate change.