Sustainable Energy-efficient Microgrid – A Case Study on Local Energy System Design

Abstract

Increasing environmental concerns about the use of fossil fuels have gen-erated great interest in emerging technologies to produce clean energy. Current research aims to mitigate this concern by proposing solutions for applying clean energies in residential buildings. This thesis focuses on mi-crogrids, small energy grids to generate, consume and share energy among producers within their own networks. Microgrids can come in dif-ferent sizes and be based on various electricity generation sources.

This research modelled and designed a microgrid solution that is sustainable, energy-efficient, economically viable and easily implemented. To achieve these goals, the design of a community of residential buildings is reverse-engineered in order to scale down the microgrid model into smaller seg-ments for simplifying the management of energy in individual and groups of dwellings. This research presents a sequence of approaches to optimally utilise dis-tributed energy resources, such as PV systems, battery energy storage, thermal storage and electric vehicles, with the aim of minimising imports from utility electricity grids, as well as helping houses, buildings, and communities to reduce energy bills. The optimisation algorithms are also tested in a hardware-in-the-loop environment to validate their perfor-mance. Furthermore, the research includes economic assessments to pro-vide a complete picture of the real value of such an approach, incorporating the cost of the new assets (e.g. batteries) and the effects of different pric-ing strategies. The research starts with the design of a DC microgrid for single-family homes, leading to the development of a community model consisting of eight dwellings in a neighbourhood. The model is implement-ed for daily, monthly and yearly time spans to verify that the proposed ap-proach works across different time scales.

The results of this thesis, which are extended from a small dwelling model to a community model, from one-day energy management analysis to a year-long energy sharing assessment, would benefit researchers, grid utilities, power companies and city planners in order to provide better solu-tions for a future carbon-free environment.