日治時期的「臺灣電力株式會社」（以下簡稱「臺電」）長期被視為推動臺灣工業化的能源單位。以往研究中常將臺電轄下各水力及火力發電廠之「裝置容量」做為計算標準，但這並不能反映電力系統運作的真實情況。「裝置容量」係每部發電機組的最大值，但不一定是實際的發電量，因為一座電廠要如何調度，要視電力系統的負載而定，在近代臺灣電力系統由北、南、中的順序發展中，電力系統慢慢由點連接成線，繼而在日治後期將全島規劃為完整的輸電網。如何有效率地調整各發電機組的使用率，成為臺電重要課題。因此每部發電機組的裝置容量，實不可能全天保持運作，因此以實際發電量估算，才能貼近電力系統運轉的真實狀況，更可看出全臺輸電網及日治時期最大水力發電廠：日月潭水力發電廠完工前後，臺電在電力系統調度上的差異。並以真實發電量為基礎，進一步觀察臺電擴建電廠與平衡供需上的努力與侷限。

The Taiwan Power Company ("Taipower" hereafter) of Japanese rule period was a long-recognized power unit that drove Taiwan's industrialization. In the past research, the "installed capacity" of hydroelectric or fire power plant subject to Taipower was often used as accounting standard; however, this method could not reflect the actual situation of power system attempering. "Installed capacity" is the maximum of generator equipments, but it is not necessary the actual power generation, because the power plant attempering is subject t to the load of power system. During the modem development of Taiwan power system with the order from the north to the middle and than to the south, power systems were gradually forming a line from dots, and than an islandwide power transmission net was completed during the late period of Japanese rule. Since then, effective adjustment of generator equipment's use rate came into focus of Taipower. As a result, it is not possible for the installed capacity of every generator equipment to be operated all day long. That explains the reason why it is the actual power generation estimation that reveals the real situation of power system operation. It also shows us the difference of Taiwan's power attempering situation before and after the accomplishment of islandwide power transmission net and the largest hydroelectric power plant in Japanese rule period--Sun-Moon Lake Hydroelectric Power Plant. In this study, we also base on the actual power attempering situation to observe the efforts and limits for Taipower's enlargement and supply-demand balance.