再生能源民營電廠之競爭行為的賽局理論分析

Abstract

民營再生能源電廠的設立已是世界潮流，而其競爭行為及效果的相關理論分析仍屬有限。本計畫擬就再生能源民營電廠與傳統大型集中式電廠間的競爭行為進行理論分析，並找出各種可能Nash均衡結果所對應的價格、數量、利潤、消費者剩餘、環境損害、社會福利等。本計畫的基本模型設定如下：賽局有兩家發電廠，電廠1為小型民營再生能源廠商，電廠2為大型公營石化能源廠商。廠商1的邊際成本為固定，但具有發電容量上限。廠商2的邊際成本遞增，但不具有發電容量上限（參考Ameli et al. (2008) 的設定）。賽局有兩階段，階段1中電廠1（民營再生能源電廠）選擇其發電量，階段2中電廠2（公營石化能源電廠）按照保證買回價格收購電廠1的發電量，然後再選擇其自身的發電量，再將購回發電量及自身發電量輸配給用戶。此外，公營石化能源發電廠每單位發電量的污染排放係數，高於民營再生能源發電廠。接下來我們將放寬基本模型，讓電廠2（公營石化能源電廠）扮演先動者。另外，分析N家民營再生能源電廠下的寡占競爭。此外，也將分析電價受到管制下、再生能源收購價格變動下，民間再生能源發電廠與公營石化能源發電廠的競爭行為的變化。簡言之，本研究分析民營再生能源電廠與公營傳統能源電廠的競爭行為，亦將討論電價管制及再生能源發電收購價格變動，並分析其所對應的經濟效果與環境影響。

Since the renewable power generation technology emerges and dispersed generation concept is widely discussed, the conventional big-scale, central generation approach has been challenged. Lots of renewable and small-scale generation units which located in residential areas, industry parks, campuses can provide electricity service in the neighborhood. The electricity industry companies have to face such a change. This project tries to take two kinds of power plants’ interaction under the Stackelberg competition: One kind is the conventional energy, big-scale power plant. The other is the renewable energy, small-scale power plant. The electricity generated by the private, small-scale, renewable energy power plant will be purchased by the public, large-scale, conventional energy power plant at the guaranteed purchase price required by the law. The emission coefficient of the public conventional energy power plant is higher than that of the private renewable energy power plant. Analytical results of market price, outputs, profits, consumer surplus, emission levels, and social surplus are discussed. The assumptions can be relaxed in extensions of the basic model to incorporate the cases of N private renewable energy firms, regulated electricity sale prices, and changes in electricity purchase price.