一种电量管理方法，运行于用户群代表或聚合商的电量管理系统中，其步骤如下。接收卸载请求。取得多个卸载用户及其多个卸载量。判断是否有历史记录的其他卸载请求。若判断有历史记录的其他卸载请求，则依据多个卸载用户的多个中途退出概率与多个卸载量计算多余卸载量，以及自多个历史事件找出此卸载请求的相近历史事件。若存在此卸载请求的相近历史事件，则依据相近历史事件中的发电端之请求总卸载量、多个卸载用户的实际总卸载量与多余卸载量决定虚拟备载容量。

An electric load management method, executed in an electric load management system of a user representative or an aggregator, has the steps as follows. Receiving a shedding request. Obtaining shedding users and shedding amounts thereof. Determining whether other shedding request in a history list exists. When determining the other shedding request in a history list exists, calculating a redundant shedding amount according to dropping-out probabilities and the shedding amounts of the shedding users, and finding a similar historical event of the shedding request among historical events. If the similar historical event of the shedding request exists, determining a virtual margin capacity according to the redundant shedding amount and a requested total shedding amount of a power supply end and an actual total shedding amount of the shedding users in the similar historical event of the shedding request.