A model for optimal energy management in a microgrid using biogas

A more sustainable energy matrix can be achieved through an integrated approach to energy generation and end-consumer self-production. This alternative can reduce consumer energy costs and enable the maturation and boosting of distributed generation technologies. Using reliable cost models with smart-grid technologies enables more economically efficient energy systems. Previously disregarded energy solutions can become viable solutions, such as electric energy generation using biogas. In this context, the contribution of this study is threefold. First, we develop a cost model of electrical and mechanical energy generation for local consumers in microgrid-producing biogas. Second, we integrate into the model a dual-fuel motor to generate electrical energy using a variable mixture of biogas and other fuel and the biomethane upgrading system to supply the mechanical demands. Third, based on this model, an optimal energy management tool is proposed. The performance of this tool is analyzed through scenario simulations of an existing microgrid composed of a motor engine fueled by biogas produced internally, a photovoltaic (PV) system, a battery bank, and connected to the utility. The results indicate the economic advantages of adopting the tool and the usefulness of the proposed model. Besides the reduced electricity cost, it also allows analysis of how each piece of equipment contributes to the electricity cost, which can be helpful in future decisions about equipment sizing.