This paper presents a cost-effective approach for building energy usage management through energy usage optimization of available building energy sources. An energy cost reduction model is developed considering grid energy usage and cost, generator energy usage and cost as well as carbon emissions tax penalties associated with scope 1 emissions. The model selects optimal times to use either Grid energy, generator energy, or a combination of the two to minimize the overall building energy usage cost. A case Study is presented where the developed model is applied for different business tariffs across two buildings in a South African based University campus. The results of the study show a 37% decrease in the maximum demand and maximum demand cost for the fixed tariff, and a 27% decrease for the TOU tariff billed by the grid energy provider. A 9% average monthly decrease in energy usage cost for time of use business tariff and a 4% energy usage cost decrease for the flat tariff was achieved through the usage of the developed model. The outcomes of this study highlight the importance of optimization of existing energy resources to reduce operating costs prior to consideration of alternate sources of energy.
The optimal grid generator file can be run on Matlab. All inputs are in the code.