臺灣發電成本之再評估：淨零轉型下之均化能源成本及電力供給曲線分析

Abstract

臺灣於2022年公布「2050淨零排放路徑」，目標將再生能源滲透率提升至六成以上。然而，臺灣目前仍缺乏以在地參數建立、可公開比較且可動態更新的發電成本與電力供給曲線資料，限制了政策規劃與市場分析的精確度。本研究整合台電自有機組與代表性再生能源專案的成本與性能參數，計算各主要技術的均化能源成本（LCOE），並納入儲能、輸電與備援等系統成本，以反映高滲透率間歇性再生能源的整合需求。同時，依邊際成本與即時發電量繪製供給曲線，分析不同碳定價情境下的出力排序變化。 研究結果顯示，陸域風電與中大型小水力發電是目前少數具成本競爭力的再生能源，其均化能源成本與燃煤、燃氣發電相當，甚至更低；其他再生能源技術則因資本與運維成本偏高，成本普遍高於傳統火力機組。與日本、南韓、美國、中國及全球平均相比，臺灣多數再生能源成本仍處於高檔，特別是離岸風電與太陽光電，反映出規模化程度不足、建設條件受限及容量因數偏低等結構性挑戰。燃煤與燃氣發電的成本高度依賴燃料價格，國際市場變動可在短期內大幅改變其經濟性；在碳定價達1,500元/tCO₂e的情境下，燃煤成本將顯著上升並高於燃氣，供給曲線出現燃煤與燃氣排序反轉，驗證「減煤增氣」政策在經濟面與減碳面的合理性。將系統成本納入後，間歇性再生能源的實際發電成本可增加三至八成，凸顯在高滲透率情境下忽略系統成本可能低估其真實成本。 本研究建立了一套在地化、可比較且可動態更新的 LCOE 與供給曲線資料，補足傳統成本分析無法反映的系統運作特性。結果顯示，若要在2050年前兼顧淨零轉型與供電穩定，臺灣需加速具成本競爭力再生能源的佈建，同時降低離岸風電與太陽光電的資本與運維成本，並透過系統成本內部化與邊際成本排序引導投資與調度策略。

In 2022, Taiwan announced its “2050 Net-Zero Emissions Pathway,” setting a target to raise the renewable energy penetration rate to over 60%. However, Taiwan still lacks locally parameterized, publicly comparable, and dynamically updatable data on power generation costs and electricity supply curves, limiting the accuracy of policy planning and market analysis. This study integrates the cost and performance parameters of generation units owned by Taipower and representative renewable energy projects to calculate the levelized cost of energy (LCOE) for major technologies, incorporating system costs such as storage, transmission, and operating reserve to reflect the integration requirements of high-penetration intermittent renewables. In addition, supply curves are constructed based on marginal costs and instantaneous generation output to analyze changes in dispatch order under different carbon pricing scenarios. The result of the study shows that onshore wind power and medium-to-large small hydropower technologies are among the few renewable energy sources that are cost competitive, and their LCOEs are comparable to or even lower than coal- and gas-fired generation. Other renewable energy technologies, affected by relatively high capital costs and high operation & maintenance costs, generally remain more expensive than conventional thermal power technologies. Compared with Japan, South Korea, the United States, China, and the global average, most renewable energy costs in Taiwan remain at the higher end of the cost spectrum, offshore wind and solar photovoltaics in particular, reflecting structural challenges such as insufficient economies of scale, site constraints, and low capacity factors. The costs of coal- and gas-fired generation are highly dependent on fuel prices, with international market fluctuations capable of significantly altering their short-term economics. Under a carbon price of NT$1,500/tCO₂e, the cost of coal-fired generation rises significantly and exceeds that of gas-fired generation, reversing their positions on the supply curve and supporting the economic and decarbonization rationale of the “Increase Natural Gas, Reduce Coal-fired” (coal-to-gas transition) policy. When system costs are included, the actual generation costs of variable renewable energy technologies increase by 30% to 80%, highlighting the risk of underestimating their true costs under high-penetration scenarios if system costs are ignored. This study develops a localized, comparable, and dynamically updatable dataset of LCOE and supply curves, addressing operational characteristics that traditional cost analyses fail to capture. The results imply that to achieve both a net-zero transition and power supply stability by 2050, Taiwan must accelerate the deployment of cost-competitive renewables, reduce the capital and operation and maintenance costs of offshore wind and solar photovoltaic, and guide investment and scheduling strategies based on internalized system costs and the marginal cost-based dispatch order.