大規模風光發電對台灣發電系統備用及備轉容量之影響分析

由於日本發生福島核災，我國改採「非核家園」電源開發政策，據之，以太陽能裝置容量20GW、風能4.2GW作為2025年的政策目標。台灣發電系統可靠度係採用缺電機率小於0.1%為規範，據此訂定台灣發電系統「備用容量率」的水準，俾因應系統內發電機組的檢修、故障、不確定之水文、新建機組的工程延宕以及長期負載預測誤差等不確定因素。本論文擬分為兩部份，第一部分首先探討大規模風光發電對於台灣發電系統可靠度的貢獻，稱為風、光發電的「容量價值」或「可靠容量率」，據此評估至2025年台灣發電系統適用的「備用容量率」水準。除設置相對於年尖峰負載的額外發電機組容量或稱備用容量之外，為因應風、光發電出力的不確定性及變異性，於2025年的台灣發電系統另須具備充裕的機組調度彈性，包括：(1)機組的快速升/降載能力；(2)鉅額風、光發電之下，風、光發電設備所不能提供的旋轉慣量與調頻備轉容量等。本論文第二部份將探討2025年台灣發電系統在大規模風、光發電之下系統24小時發電量所形成的鴨子曲線，以及為因應鴨子曲線台灣發電系統應具備的調度彈性，包括：(1)系統於日出與日落時段傳統複循環機組之急速升/降載率；(2)於日照時段燃煤機組可能之減載運轉以及因應系統旋轉慣量與調頻備轉可能之不足而另須調整抽蓄機組等之運轉模式等。本研究成果可作為台灣發電系統長期規劃以及發電系統因應鴨子曲線所需之彈性運轉方案制定的參考依據。

關鍵字

再生能源；備用容量率；備轉容量；升/降載率；旋轉慣量；調頻備轉；抽蓄水力

並列摘要

Because of the March 11 of 2011 nuclear disaster in Fukushima, Japan, Taiwan Government has changed her nuclear development policy for Taiwan to become “a non-nuclear state”, based on which, to develop her long term power generation program. The solar power installation capacity of 20GW and the wind of 4.2GW are the policy goal for year 2025. According for the reliability requirement set by the Government, Taiwan power generation planning must meet with the loss of load probability (LOLP) less than 0.1% requirement. To meet with this requirement, Taipower and the Government jointly set the “system generation reserves” and the “system reserve margins”, so to provide the generation capacity to meet with the long term uncertainty including the overhaul and forced outage of generation units, the uncertain rainfall, the unpredictable engineering postpone on the generation units to be commissioned, as well as the forecast error on system load growth, etc.. The thesis contents are twofolds. The first part focuses on the evaluation of capacity credit in respective of wind and solar for the Taiwan power generation system up to year 2025. On basis of the credit values obtained, the thesis then evaluates the acceptable “system reserve margins” for the Taiwan power generation system up to the same year. Due to the uncertainty and variability features of wind and solar power, Taiwan's thermal power generation system in year 2025 must have additional system operation flexibility, which contains: (1) fast ramping rate for the generation units; (2) high rotational inertia and frequency control reserves, both the wind and solar cannot provide. The second part of this thesis will explore the 2025 Taiwan power generation system under large-scale wind and solar power penetration to ensure that the system be able to meet with the operation needs caused by the duck curve, such as: (1) the need of high ramping rate for the thermal units during the sunrise and sunset intervals, and (2) the need of additional contingency reserves including the pump storage units to serve as fast frequency control reserves and the need of reduced production and even two-shift operation of coal-fired units, both during the daytime with high output of the photovoltaic generation. The thesis results can be valuable to the long term planning of Taiwan power generation system and to the preparation of future flexible power operation programs to cope with the duck curves.

並列關鍵字

Renewable Energy ； Reserve Margin ； Operating Reserves ； Ramping Rate ； Rotational Inertia ； Frequency Control Reserves ； Pump Storage Generation Units