Decision-Making Framework to Identify the Optimal Hybrid Renewable Energy System for Switching UK Representative Domestic Buildings Towards the Net-Zero Target

Abstract

UK’s building stock remains one of the most inefficient and oldest in Europe. The non-retrofitted old building stocks need more energy to meet occupants’ energy demand and are responsible for significant fossil energy consumption and greenhouse gas (GHG) emissions. Such building stocks are referred to as difficult-to-treat buildings. The ongoing retrofitting work has successfully reduced energy consumption in difficult-to-treat buildings. However, space heating, electrical appliances, and lighting still rely on fossil energy in retrofitted difficult-to-treat homes. The hybrid renewable energy system (HRES) is becoming a feasible solution to replace fossil energy in such homes. HRES refers to a system containing two different renewable systems/sources to work with/without energy storage, simultaneously supplying different demands (i.e., electricity, space heating, domestic hot water). A viable HRES is a most economically and practically feasible and environmentally friendly solution. However, the existing studies have not explored the optimal HRES for the UK retrofitted domestic buildings using the multi-criteria decision-making method. The different aspects need to be considered simultaneously in the multi-criteria decision-making process, resulting in the exploration of the HRES performance from different perspectives, thereby strengthening the reliability of the decision-making results. The consideration of multiple criteria ensures that the identified HRES reflects real needs. Furthermore, it will holistically align the retrofitted buildings with the current energy policy and the climate change targets. This research has created a multi-criteria decision-making framework that considers the criteria/indicators aligned with the associated UK energy policy, climate change targets and existing assessment standards. The framework helps collect the viewpoints of householders and build a weighting system to quantify and rank the collated multiple viewpoints using Fuzzy-AHP (Fuzzy-Analytical Hierarchy Process). The framework helps householders easily compare the advantages of using the suggested renewable systems and the existing energy systems, encouraging householders to invest only in viable systems. It also evaluates the feasibility and effectiveness of using renewable systems to change domestic buildings towards the net-zero target. The framework outcomes will also help policymakers enhance the relevant energy policy and the corresponding financial incentives. In addition, the results drive the new energy policy development that supports renewable energy systems, an affordable and practical energy supply strategy for buildings, moving steadily on the net-zero pathway forward.