台灣地區太陽能發電系統投資效益分析

Abstract

本研究除依據再生能源發電設備設置管理辦法探討設置型式的適用性外，另將台灣的六個都會區，依據第三型系統容量、躉售電價及所定義的各項財務參數假設估算等條件，應用Excel軟體載入運算，後續以淨現值、內部報酬率、折現後回收年限及自償率等財務評估方法與決策準則，分析各區域自有資金及融資等資金方案的設置效益，最後再透過個案敏感度分析，整理影響因子的風險等級。為使各參數估算較具有參考價值，採用2004~2012年中央氣象局各地區之日射量資料，載入太陽能專用之發電量模擬軟體PVsyst，以推算出各地區的年發電量，並探討躉售公式中年可售電量參數的合理性。而於系統造價部分，採用工作分解結構及單價分析之方式編列預算書，以推算出較接近市場行情之系統建置成本。 經分析後發現第一、二型的太陽能系統型式，於建築物如交大光復校區同屬分散的座落型態，應適當的放寬併聯及躉售的規定，以符合經濟投資及節能減碳的多重效益。於計畫成本與收益部分，發現除模組及逆變器兩項關鍵設備約為造價的50%。年可發電量約為日射量的80%，於計畫初期藉此比例關係可快速推估出造價及年發電量外，並得知台中以北的新竹、台北地區年可發電量與躉售公式中全台灣統一訂定為1,250kWh(度)的差異達24.45~31.23%，有失鼓勵民間參與再生能源政策的公平精神。經效益計算後嘉義地區採融資方案，容量分別為98kWp、497kWp之太陽能系統符合業者觀點的投資決策準則，內部報酬率大於WACC 5.62%、淨現值大於零、折現後回收年限低於營運期1/2，10年，且自償率大於1之要求。如不局限需將系統設置於同一地區，可將五個容量98kWp集成為一個490kWp之系統做設置，在具有相同的量體採購價格及有部分成本不需支出的條件下，整體造價較低，且躉售電價反而較高，如資金配合融資方案，為業者於台灣地區投資太陽能之首選。於風險管理部分，經敏感性分析後得知，以系統年發電量的風險最高，接著為建置成本、貸款比例，故應對此三大影響因子嚴加控管，以維護預期之投資效益。

This Study is based on the applicability of Renewable Energy Power Generation Device Setting Management and divided Taiwan into six metropolitans. Using Excel application to assume the financial parameters estimates, according to system capacity set up range of type III, wholesale price and other conditions, follow up with Net Present Value, Internal Rate of Return, Discounted Payback and Self-Liquidating Ratio of financial decision criteria through the way of one’s own or financing in order to analysis the benefit of solar energy power system to set up in each region. By case sensitivity analysis, it will sort out the risk factors of each graduation. In order to make the financial assessment valuable, it will use solar insolation data from Central Weather Bureau start from 2004 to 2012 and then upload into the software PVsyst for dedicated electricity energy simulation of the amount of annual capacity of each region. And will use the Work Breakdown Structure (WBS) and unit price of the valuation to budget the implementation cost which is closer to the market of the system cost. After analysis, the building of Chiao Tung University Kuang-Fu campus is located at a scattered pattern which belongs to type I and II. It should be appropriate to relax restriction for parallel and wholesale, in order to achieve multiple benefits of economic investment and carbon reductions. We can find out from the part of program cost and benefits, two major equipments which are modules and inverters will account for 50% of total manufacturing cost; and annual generated capacity will be 80% of daily insolation, which could get a quick estimate of manufacturing cost and annual generated capacity by this percentage in initial plan. Also would get to know that, the annual generated capacity and the unified set of 1,250kWh degrees of wholesale formula was 24.45~31.23%, which was diverge from the annual capacity of northern part of Taiwan such as Hsinchu and Taipei area, which disobey the spirit of encourage private participation to renewable energy policy. After benefit calculating, only in Chiayi, Taiwan with the capacity of 98kWp and 497kWp respectively for financing policy has investment benefit. Internal Rate of Return is greater than Weighted Average Cost of Capital 5.62%, Net Present Value is greater than 0, Discounted Payback is less than the operation period of 1/2 (approximately 10 years), and Self-Liquidating Ration is greater than 1. If the case is not confined to set up the system in same area, it can integrate five of each 98kWp into a 490kWp capacity system, and it will have lower purchase price and higher wholesale price than compared to the same capacity but with each 98kWp, which will have maximum benefit of the investment. Sensitivity analysis shows that the annual generation capacity of the system has the highest risk, followed with implementation costs, and the proportion of loans, so investors should make a strict control of this three impact factors in order to maintain the expected investment returns.