臺灣水資源多年來供不應求的問題，由於供給面管理已面臨瓶頸，不得不尋求以強調經濟誘因，效率使用為理念的需求面管理。水權交易制度是需求面管理政策中最符合價格機能運作的制度，本文由臺灣的水資源財產權演進的歷史，以及理論模型的推導，加上既有文獻的探討，和國外施行的經驗，認為此制度確實可行。它的優點是讓用水者面對真實的機會成本，可以增加用水效率，除此之外，還可分散缺水風險，使分配更具彈性，反應留川使用效益的公共價值，並且可以顧及公平性和增進整體社會福利。雖然此制度有其缺陷，但是藉制度的設計，政府適當的管制，應可克服這些問題。 　　國內現行的水利法不允許水權自由交易，其中充滿政府管制色彩。在制定之初幾乎不顧及經濟法則，但是隨著由供需主導的經濟力量，例如嘉南平原水權之爭，已迫使水利法的修正，允許需由政府核准的附帶補償的移轉，這新增條文的精神已離自由交易不遠。不過由各種跡象顯示，政府對水資源的管理態度將更強調對水資源調配的主控權，但是此主控權的行使，四十年以來一直拋不開各種包袱，在未來也很難相信主管機關能做到社會最適的調配。 　　本文所提出的理論模型，是為了做政策上的選擇。參考Baumol and Oates(1988)，徐世勳（民國80年），蕭代基（民國81年）等的模型架構，將留川及離川使用交互影響的關係，以及污染排放因素模型化。並討論在確定及不確定下的政策選擇，比較Pareto最適條件及市場均衡條件，在水量方面，主要是是探討水權費及水權交易制度，在水質方面，比較污染排放稅和可轉讓污染染排放許可證。論文結果發現，在確定情況下，上述政策無差異。在供給函數不確定下，應採水權交易制度和污染排放稅。本文最後提出政策建議，以集水區地方自治組織，來輔助市場交易，以及外部效果內部化工作。本文目的除了在財產權歷史和理論上做進一步探討，也希望提供臺灣成立水權交易制度政策上的參考。

本研究針對先進國家「用戶群代表」制度之政策與法規進行探討，並進一步探討如何施行於台灣電力市場。首先定義並解釋「用戶群代表」涵意後，整理出先進國家(包含美國、歐盟、德國、澳洲、韓國五個地區與EnerNOC、Comverge、CPower、OhmConnect四個公司)的用戶群代表商業模式案例，藉由文獻分析與個案研究，觀察先進國家政策方向與用戶群代表市場定位差異。同時，本研究由我國用戶群代表相關制度法規，探討用戶群代表於我國電力市場實施之適法性。此外，本研究根據文獻回顧整理出發展用戶群代表制度的關鍵成功因素，並詳細探討我國當前條件是否適合發展。最後針對政府與台電、產業界、學術界、電力用戶的不同角度，提出可行的政策法規建議。 / This thesis explores the policies and regulations of aggregator systems in advanced countries and explores how to implement aggregator system in Taiwan electricity market. In order to achieve this objective, we first define and elaborate the meanings of aggregator. Then, experience and case studies of USA, European Union, Germany, Australia and Korea are studied. In addition, business models of four aggregators, EnerNOC, Comverge, CPower and OhmConnect are presented. Furthermore, we examine current related regulations of an aggregator in Taiwan electricity market for feasibility analysis. In addition, this study summarizes the key success factors of the development of aggregator systems according to the literature review, and discusses in detail whether Taiwan's current conditions are suitable for development. Finally, market models and policy regulations in relation to the aggregator are recommended.

過去電力事業為了滿足電力用戶之需求，對於新電源之開發不遺餘力。然而由於電力事業近年來在供給面規劃屢遭當地居民抗爭而受阻，因而晚近轉而強調用戶需求面之管理。 本文針對台電公司現行需求面管理之「用戶計劃性減少用電措施」四種方案進行研析。首先設定簡化條件，將四種方案予以模型化，利用經濟剩餘模型，進行邊際分析，探討台電公司提供優惠之折扣比例及電力的價格需求彈性如何參與用戶抑低容量以及消費者剩餘、生產者剩餘分配之效果。分析結果顯示：「計劃性（二）」抑低用戶負載容量最高，且參與用戶之消費者剩餘最多；「計劃性（一）」抑低用戶負載容量最低，且參與用戶之消費者剩餘最少。另一方面，若從電力公司之視角觀之，「計劃性（二）」之生產者剩餘最低，而「計劃性（一）」之生產者剩餘最高。 經濟剩餘模型分析中，由於未能充分考慮供需雙方之潛在成本與效益，因此實務上之解釋能力有其侷限之處。基於上述緣由，本文接著藉由成本效益分析，將方案實施之潛在成本與效益納入考量，分別從參與用戶之角度進行參與者檢定（Participant Cost Test, PCT）以及從電力公司之角度進行公用事業成本檢定（Utility Cost Test, UCT），以檢視不同方案在不同觀點下之績效表現。成本效益分析結果顯示：在PCT檢定下，「計劃性（四）」參與用戶之益本比最高，「計劃性（二）」參與用戶之益本比最低。而在UCT檢定下，「計劃性（一）」電力公司益本比最高，「計劃性（四）」電力公司益本比最低。將成本效益分析與經濟剩餘模型比較後可發現，用戶抑低容量高的方案對於電力公司而言未必最有利。 最後，為進一步探討關鍵變數變動造成不同方案間成本效益值之影響，因此進行敏感度分析。敏感度分析的結果顯示：若電力公司為吸引用戶而提高誘因，增加各方案給予用戶優惠折扣之比例，以參與用戶角度而言，「計劃性（四）」參與者檢定之益本比提高幅度最大；以電力公司角度而言，「計劃性（四）」公用事業成本檢定之益本比降低幅度最大。若電力公司提高參與用戶每次抑低用電負載之時數，以參與用戶角度而言，「計劃性（四）」參與者檢定之益本比降低幅度最大；以電力公司角度而言，「計劃性（四）」之公用事業成本檢定益本比提高幅度最大。 / In order to meet the users’ demand of electricity, the electric power utility spared no effort to develop the new power plant in the past. However, in recent years, the electric power utility have been hampered by local residents on supply-side planning, thus more emphasize is being put on users’ demand-side management（DSM）. This paper aims to analyze four projects of Taipower’s existing demand-side management of “incentive plan for customers’ scheduled load curtailment program”. First, we set several simplified conditions for modeling the projects. By using the economic surplus model and conducting the marginal analysis, the impact from the discount incentive provided by the utility and the elasticity of electricity price demand is explored－on participants’ load capacity reduction and the distribution of consumer surplus and producer surplus. The results of economic surplus model showed "project 2" curtails the maximum load capacity and with the highest consumer surplus; "project 1" curtails the minimum load capacity and with the lowest consumer surplus. On the other hand, in the Taipower's point of view, "project 2" provides with the lowest producer surplus while "project 1" gives the highest producer surplus. In the economic surplus model, since the potential costs and benefit were not fully considered in both supply and demand sides, several limitations exist on this model. Based on the above reasons, we utilize the cost benefit analysis, taking the potential cost and benefit into account and conducting Participant Cost Test（PCT） from the participants’ perspective and Utility Cost Test（UCT）from the utility’s perspective to examine the performance under different 4 DSM projects in different point of view. The results of cost benefit analysis showed that in the PCT test, the "project 4" comes up with the highest benefit cost ratio while "project 2" has the lowest cost benefit ratio. In the UCT test, the "project 1" has the highest cost benefit ratio while "project 4" came with the lowest cost benefit ratio. Comparing the cost benefit analysis with the economic surplus model, we could find that the project with the most load capacity reduction may not be the most favorable project for the utility. Finally, in order to further explore the key variables affecting the cost and benefit value in different projects, we simulated several scenarios for sensitivity analysis. The results of the sensitivity analysis showed that if the utility increases incentives to increase four projects’ ratio of discount for attracting participant, in the participants’ perspective, "project 4" would have the most changed rate of cost benefit ratio（increase）; in the utility's perspective, "project 4" would have the highest adjusted rate of cost benefit ratio（decrease）. If the utility increases the load curtailment duration each time, in the participants’ perspective, "project4" would have the highest adjusted rate of cost benefit ratio（decrease） ; in the utility’s perspective, " project4 " would have the highest adjusted rate of cost benefit ratio（increase）.