Technical KPIs for microgrids

The design of electrical systems with renewable and conventional in-house generation involves economic, environmental and technical aspects. Often these instances are conflicting: conventional sources have lower Capex and good controllability, while renewable sources have lower Opex and are environmentally friendly but often present erratic behaviors. For these reasons, the best design solution is typically a variable mix of conventional and renewable sources. Today no standardized tool or procedure is available for evaluating and quantifying the technical aspects that drive the design of a Microgrid. Economical aspects are a consequence of the selected set-up, and may lead to an iterative design. This paper defines a set of technical Key Performance Indexes (KPI) that gives a quantitative evaluation of the technical performances of a Microgrid for the comparison of different design solutions. The proposed KPIs consider the system stability, the power quality, the saved fossil fuel, and the maintenance demand for conventional machines, and they can be used for an economic analysis of different technical solutions and sizing.