Reliability Optimisation of a District Multi-Energy System

Abstract

With the growing share of fluctuating renewable energy sources, energy infrastructures are facing increasing challenges in flexibility and reliability. If today’s common practice of arbitrary electricity consumption or feed-in at the distribution level continues while the share of uncontrollable, decentralised renewable power increases, grid overloading and local blackouts could become more frequent. This study explores the design of a district multi-energy system, participating in a day-ahead electricity market. Reliability of energy supply, both to the loads and to the electrical grid are investigated with respect to forecast errors in energy demands and renewable energy pro-duction as well as failures of components within the district energy system. A case study of a Swiss district with a low-temperature thermal network, decentralised heat pumps and solar panels shows that considering reliability encourages the deployment of backup generation and an increase in battery and thermal storage, leading to more than 99.98% of yearly energy demands being met. When introducing an optimised district energy system, the yearly amount of balancing energy is reduced from 17% to less than 0.8% of the total electricity exchange with the grid, indicating that such a district could perform well in the considered market situation.