The Investment Feasibility Assessment on Heavy Metal Contaminated Farmland Setting up Photovoltaic System

台灣是個多山的島嶼，平原面積少於30%，農地資源的品質值得努力維護。近35年來，部分農地長期受工業廢水的重金屬污染，導致所生產之農作物重金屬超標有礙國人身體健康，解決農地重金屬污染同時兼顧土地利用機會的方法，並恢復農地可再作為糧食生產用途的最大可能性，實在有其必要性。2016年環保署訂定「受污染土地改善及太陽光電設置併行審查作業原則」，公告以植生復育法進行污染農地改善並設置太陽光電設施之辦法，除整治污染農地的翻轉稀釋法、客土排土法整治外，提供新的改善受污染農地整治模式，並吸引太陽光電業者來投資設立太陽光電設施，同時產生售電收入彌補土地租金給停耕的農民。本研究利用此契機，探討受污染農地以植生復育法改善污染並搭配建置太陽光電設施投資之可行性評估，所使用的評估方法是回收期間法與淨現值法。因日照量對於植物生長與太陽光電設施發電是彼此競爭的，本個案分析以太陽光電設施建蔽率40%，植物生長最低日照量需求為60%作為基本假設，進行投資可行性分析。根據建置成本、躉購費率、運維成本、保險費用、土地租金，將這些相關的影響因子納入投資可行性分析的假設與參數設定，區分無融資案例與融資案例研究投資可行性評估。本研究分析結果顯示，融資案例之投資評估淨現值大於零，是本研究解決農地受重金屬污染問題的最佳解決方案，無融資案例因淨現值小於零，相對是次佳的解決方案。As Taiwan is a mountainous island with plains account for less than 30% of the island. The quality of farmland becomes very precious to be well preserved. In the past 35 years, some farmland have been polluted by heavy metals from industrial waste water for a long time, which has led to high residues of heavy metals in crops threatening the health of people in the country. Remediation of farmland contaminated by heavy metals is of great importance and increase the utility to restore the possibility of agricultural land as a crops production. In 2016, the EPD formulated the 'Soil Pollution Remediation with Photovoltaic System Act' and announced the method of remediation of contaminated farmland via Phytoremediation by setting up the photovoltaic system in addition to the remediation method of mixing soil and replacement soil for contaminated farmland. It provides new ways to improve the remediation of contaminated farmland, attract photovoltaic developers to invest in setting up photovoltaic system, and at the same time generate revenue from electricity sales to make up for land rent to farmers who have stopped farming. This study took advantage of this opportunity to explore the feasibility assessment by setting up a photovoltaic system on pollution sites with Phytoremediation to improve the heavy metal polluted farmland. The assessment methods used were the payback method and the net present value method. The role of photoperiod in plant growth and photovoltaic is competed with each other. The case study analyzes the investment feasibility with the photovoltaic system shading rate of 40% and the minimum plant sunshine growth requirement of 60% as the basic assumption. According to the construction cost, purchase fee rate, operation and maintenance costs, insurance costs, and land rent, these influencing factors setting up costs, fee-in tariff price, operation and maintenance costs, insurance fee and rent are included as the assumptions and parameters. The self-financing case and bank-financing case studies are evaluated for investment feasibility assessment. The analysis results show that the net present value of bank-financing case is greater than zero which is the best solution to improve the heavy metal polluted farmland. However, the net present value of the investment in self-financing case is less than zero that is the sub-optimal solution.摘要 i Abstract ii 目次 iii 圖表目次 v 第一章 緒論 1 第一節 研究動機 1 第二節 研究目的 2 第三節 研究範圍及限制 2 第四節 研究方法 3 第五節 研究架構 4 第二章 再生能源與受污染農地現況 6 第一節 國家能源政策 6 第二節 自然限制因素 8 第三節 土壤中重金屬的來源與行為 16 第四節 污染土壤復育方法 19 第三章文獻回顧 22 第一節 本土植生復育法作物 22 第二節 太陽光電系統電器特性 28 第三節 太陽光電設施成本及售電收入估算 32 第四節 投資可行性評估 36 第四章 投資可行性案例分析 40 第一節 受重金屬污染農地案例基本資訊 40 第二節 太陽光電設施裝置容量、營運收入及支出 41 第三節 無融資案例現金分析 43 第四節 融資案例現金分析 50 第五章 結論與建議 58 第一節 結論 58 第二節 建議 59 參考文獻 6