Manufacturing plants always look for ways to improve the quality/cost ratio of the products offered to the market to increase their competiveness. One of the production costs is energy usage. Several approaches are available for a plant to save energy, one of which is to reschedule the operation of equipment and take advantage of incentives and favorable pricing offered by utilities in order to encourage consumers to use energy in such a way that enables the utility to manage load patterns. In this paper, we present an online energy evaluation system (OEES) for manufacturing plants to find out an optimal schedule of equipment that uses energy efficiently and thus reduces the cost. OEES allows users to configure their load by specifying electrical devices and their various parameters. Then the online system will assess power consumption over a certain time period, as well as peak power demand and power factor of the defined load.