本文以《營業報告書》微卷史料統計日治時期臺灣各家民營電力公司營運數據，依每半年財務報表長時期的觀察，探討市場供需雙方之變化及營運數據盛衰的動因，做為進一步瞭解臺灣電力發展與比較的基礎。日月潭水力發電廠的蘊釀，催生了臺電，也因這個計劃的延宕，讓臺電成為市場最大的供給者，也背負最沉重的營運壓力與政策使命，常陷於市場與政策間的拉扯與糾結，形成臺灣電力發展較為特殊的一面。日本的電力市場則較臺灣具有彈性，但臺灣在初期的政策指導下，卻創造出比日本更低廉的費率與成就，對照後期數據的鈍化與日本市場飛躍性的發展，顯見政策若不能配合時代做調整，將可能是市場的阻力而非推力。臺灣市場的成長率雖呈現遞增趨勢，但平均用戶所享有的電力資源卻呈現「量升質降」的狀態，亦即整體市場雖然成長，但卻被新增用戶所「稀釋」，這不只是供給的問題，也是臺灣市場消費力未能同步的反映，其原因則因地因時而異，未可一概而論。

Based on “Business Carrying Report”, calculating data in every power companies running by local people and also according to the observation of property reports, I will discuss the reasons why the relationship between offering and needing parts is changing and why the money-earning data was rising or falling. Hereafter, we know be more clear about the processes of Taiwan electric growing. Though the ratios of Taiwan markets growing incline, the quality of power resources which each house gains declines. It's not only the problem of offering but the reflection of the consuming abilities in Taiwan don't keep up with they should be. The real reasons of those problems may differ according to various places and period of time.