不同土地類型下太陽光電發電效益與經濟比較

Abstract

隨著再生能源在能源轉型中的重要性日益提升，太陽能發電已成為關鍵電力來源之一。本研究探討氣候變數與案場特性對太陽能發電量之影響，並進一步分析不同裝置容量、發電月齡及土地類型下之異質性效果與經濟差異。

本研究以實際太陽能案場資料為基礎，建構固定效果模型，分析溫度、日照時數、雨量及案場特質對發電量之影響。實證結果顯示，氣候變數整體解釋力有限且不具穩定性，而裝置容量對發電量具有顯著正向影響，顯示發電量主要受設備規模所主導。

異質性分析結果顯示，不同案場條件下發電量之決定因素存在差異。在裝置容量分組方面，小容量案場之發電量主要受發電月齡、污染農地與所有權型態影響；大容量案場則以裝置容量與污染農地之影響較為明顯。在發電月齡分組方面，新案場之發電量主要受裝置容量影響，而舊案場除裝置容量外，溫度亦呈現顯著正向影響，顯示在營運時間較長之案場中，氣候因素之影響可能逐步浮現。

在經濟效益方面，本研究結合案場成本與售電收入進行投資報酬分析。結果顯示，在台電躉購制度（約3.6元/度）下，投資報酬率約為8%至10%；而在售電平台（約5元/度）情境下，投資報酬率可提升至10%以上。由於發電量主要受裝置容量影響，氣候不確定性對收益影響有限，使現金流呈現相對穩定性，有利於投資評估與風險控管。此外，污染農地因土地成本相對較低，在特定情境下具備較佳之經濟可行性。

整體而言，太陽能案場之發電表現與投資績效主要受設備規模、營運條件、土地類型與售電機制影響，顯示政策設計與市場機制對再生能源投資決策具有關鍵影響。

With the growing importance of renewable energy in the energy transition, solar photovoltaic (PV) power has become a key source of electricity. This study examines the effects of climatic variables and site characteristics on solar power generation, and further investigates heterogeneity across installed capacity, operational age, and land-use types, together with their economic implications.

Using real-world PV generation data, this study employs a fixed-effects model to examine the effects of temperature, sunshine duration, rainfall, and site-specific characteristics on solar power generation. The results show that climatic variables have limited and unstable explanatory power, whereas installed capacity has a significantly positive effect, suggesting that solar power generation is primarily driven by system scale.

Heterogeneity analysis reveals that the determinants of solar power generation vary across site conditions. For smaller systems, power generation is mainly associated with operational age, contaminated farmland, and ownership structure, whereas for larger systems, installed capacity and contaminated farmland play more important roles. In terms of operational age, newly established systems are primarily driven by installed capacity, while in more mature systems, temperature also shows a significantly positive effect in addition to installed capacity, suggesting that climatic influences may gradually emerge as systems age.

From an economic perspective, investment performance is evaluated by integrating project costs and electricity revenues. Under the feed-in tariff (FIT) scheme, with an electricity price of approximately NTD 3.6/kWh, the internal rate of return is about 8% to 10%. Under the power purchase agreement (PPA) scenario, with an electricity price of approximately NTD 5/kWh, the internal rate of return can increase to more than 10%. Since power generation is primarily determined by installed capacity, weather-related uncertainty has a limited impact on revenue, resulting in relatively stable cash flows and supporting investment evaluation and risk management. Furthermore, contaminated farmland, due to its relatively lower land cost, may offer better economic feasibility under certain project conditions.

Overall, the results indicate that the generation performance and investment outcomes of solar PV projects are mainly shaped by system scale, operating conditions, land-use types, and electricity sales mechanisms, highlighting the importance of policy design and market arrangements in renewable energy investment decisions.