台電公司發電機組成本估算模式之解析--兼論向民間發電業購電之調度決策

Abstract

我國現階段電業獨占的經營環境，在經濟自由化風潮的衝擊下已面臨改革的壓力，政府正積極進行電力市場結構的改革，以促成電業自由化及電力市場自由競爭。經濟部自八十二年起即研議釋出部份地區發電專營權，鼓勵民間及外商投資興建電廠，讓民間發電業進入電力市場競爭，目前經核准的七家民間發電業，裝置容量7050MW，而87年11月決定再開放第三階段民間發電業申請，預見未來民間發電廠的數目將逐漸增加。 我國電業發展之走向，最近又有重大的轉折，電業開放將朝向「垂直整合、劃分區域」的原則推動，沒有強制性電力交易市場的設計，仍維持傳統的綜合電力，而以一個以上的綜合用電彼此競爭，未來台電的電價仍受政策管制，但民間發電業可以自行訂定售電價格，在特定的區域經營綜合電業；現有與台電公司簽約的民間發電業，可以選擇與台電公司繼續維持廿五年的合約關係，以契約價格售電給台電公司賺取固定利潤，或放棄合約走向綜合電業。 發電機組檢修排程、容量成本與燃料成本，都會影響發電機組平均發電成本的估算，進而影響各種發電機組調度運轉及其發電成本，本研究的目的是希望藉發電成本的估算方式，進一步瞭解系統調度單位如何根據其成本比較，決定應先予調度何部機組發電及調整出力。標準的發電成本估算模式的構建，可以作為未來實際調度的參考依據，並瞭解未來各機組之燃料單價、燃料熱值，以及預估的發電量，才能確切掌握調度情況。理論上，多使用成本較低的機組可降低整體的發電成本，但如須考慮電廠位址，機組效率等因素時，則必須在調度的機組中作一權衡取捨，以獲致適當的機組組合。民間發電業者必須掌握這些因素，則對於決策接受調度售電會有相當助益。

Taiwan's economic liberalization policy has gradually changed the electricity industry structure. The government conducts a series of measures to deregulate the power industry and promote the market competition. MOEA has been releasing part of its monopolistic privilege since 1994. Private power producers, even owned by foreign investors, are encouraged to invest in power generation industry. Up to now, MOEA has approved seven Independent Power Producers to build power plants, installed capacity totaled 7050MW. And more IPPs will be approved in this year. The development trajectory of Taiwan's electricity industry is toward the direction of "vertical integration and area segmentation", which means the traditional power company will still exist and the compulsive power exchage system won't be adapted. Under this principle, Taipower's tariff will be still regulated, but IPPs can set up their selling price in their "territory". And the IPPs that already has contract with Taipower can sell their power to Taipower at constant contract price in the 25-year contract duration, which means their profit will be guaranteed. The factors such as outage scheduling, capacity cost, and fuel cost affect the estimation of unit average cost, then affect the dispatch decision and the actual generation cost. This study is to develop a generation cost estimation method, to analyze how the system dispatch operator makes the dispatch and output adjustment decisions. The standard generation cost estimation method is an important tool for understanding each unit's fuel cost, fuel heat value, and projected output. Beside the generation unit cost, factors such as power site location and unit efficiency are also important in dispatch decision. It will be also necessary for independent power producers to understand all of the dispatch affecting factors when they are making selling decisions.