The Electricity Act Article 40

To protect networks and maintain the safety of the power supply, Electricity Generating Enterprises and the Electricity Transmission and Distribution Enterprise shall notify the owner or occupant of the land on which the trees grow to fell or trim the trees within a given period of time, unless otherwise regulated by other laws. The Electricity Enterprise may take action to address the obstruction upon expiration of the given period or if the notice cannot be delivered.
中文原文 電業法第40條
為維護線路及供電安全,發電業及輸配電業對於妨礙線路之樹木,除其他法律另有規定外,應通知所有人或占有人於一定期間內砍伐或修剪之;於通知之一定期間屆滿後或無法通知時,電業得逕行處理。

English translation for reference only; the Chinese text prevails. Not legal advice.