審視水-糧食-能源鏈結關係下之水庫與光電埤塘智慧管理

Abstract

全球正處於能源轉型的關鍵時代，綠色能源將是未來驅動經濟發展的新引擎，而可再生能源成為新興綠色能源產業，促進台灣能源自給自足的核心能源。近年來，水、糧食、能源鏈結(WFE Nexus)之議題備受重視，因此，本研究基於提升水、糧食、能源(水力+小水力+太陽能)之協同效益，擬建立一個多目標優化模型，尋找出WFE Nexus最佳解決方案。本研究選擇石門水庫及桃園地區埤塘進行聯合供水及發電操作，實現最佳化水庫及埤塘聯合供水以滿足不同部門的基本需求，並活用水庫水量提升水力發電量、研擬在渠道上建設小水力發電機及在灌溉埤塘水面上方架設之太陽能板進行發電，增加綠色能源產量。本研究在水庫M-5規則下使用NSGA-II方法進行最佳化，並模擬覆蓋太陽能板比率、溫室用地比率、豐水年、平水年、枯水年、水庫初始庫容等情境，研究成果除了與真實水庫操作比較之外，也根據上述情境展現不同的結果，並探討其合理性。主要結果顯示 : (1) 埤塘架設太陽能板，不僅降低池水溫度變化，每年減少約47.3萬噸的蒸發量，與農業需水量相比，多了約4%的可用水量，也提供魚類穩定生長的水質條件，並增加740GWh太陽能發電，充分展現光電埤塘的潛力；(2) 石門水庫與光電池塘的最佳聯合操作不僅可以促進水庫水力發電和渠道小水力發電，同時提高供水量、增加糧食和綠色能源的生產，促進水-食物-能源鍵結的協同效益值；(3) 初期可用水量的減少，會大大影響之後水庫的操作調度；(4) 溫室的建置，對於水、糧食、能源協同效益，最大提升幅度可達7%，具有高度的發展性；(5) 此研究能提供城市永續發展趨勢相關的長、短期政策，以有效管理WFE Nexus應對都市化的趨勢，從而維持綠色增長。

The world is in a crucial era of energy transition, and green energy will serve as a new engine that drives sustainable development in the future. Renewable energy becomes the core energy to cultivate green energy industries and promote energy self-sufficiency in Taiwan. In recent years, water, food and energy nexus (WFE Nexus) has gained global attention. Therefore, a multi-objective optimization framework is proposed in this study to explore the optimal solution to the WFE Nexus for improving the synergistic benefits of water, food, and energy (hydropower, small hydropower and solar power). The joint multi-objective operation of the Shihmen Reservoir and irrigation ponds in the northern Taiwan constitutes the case study. This study aims at achieving the optimal water supply from reservoirs and ponds to fulfill basic demands from different sectors as well as increasing green energy output by using the reservoir water to lift up hydropower output, installing small hydropower in river channels, and setting up solar panels over irrigation ponds. This study applyed NSGA-II optimization method to search for the total amount of hydropower generation and the modified shortage index under the M-5 rule, and simulated the ratio of covered solar panels, the ratio of greenhouse land, wet year, general year, dry year, the initial storage capacity of the reservoir, etc. In addition, the results compared with real reservoir operations, it also presented different results according to different scenarios and discussed its rationality. The main results shows : (1) The high potential of photoelectric ponds because the installation of solar panels over irrigation ponds can 1) reduces water temperature and the evaporation of about 473,000 tons per year, it has about 4% more available water that compared with agricultural water distribution, and 2) provide water quality conditions suitable for growing fish while increasing 740GWh of solar power. (2) The optimal joint operation of the Shihmen Reservoir and photoelectric ponds not only can promote reservoir hydropower output and the small hydropower output in river channels while increasing green energy production, water supply and food production, but also can enhance the synergistic benefits of the WFE Nexus. (3) The reduction of the initial available water will greatly affect the operation and scheduling of the reservoir afterwards. (4) The construction of greenhouses are highly developmental for WFE Nexus benefits, with a maximum increase of up to 7%. (5) This study can provides long/short term policies for sustainable urban development to effectively manage the WFE Nexus response the trend of urbanization, thus maintaining green growth.