Real-world sustainability analysis of water and related energy saving schemes for the built environment

Abstract

Reduced mains water consumption and renewable electricity generation in the built environment are key sustainability challenges for a rapidly urbanising global population. This dissertation assessed the performance of various technological and management solutions for saving mains water and generating solar electricity in the urban environment. Three student accommodation blocks and two Green Gown Award winning buildings of Newcastle University in the UK, and India’s first 5-star Green Rating for Integrated Habitat Assessment (GRIHA) campus provided unique case studies for the real-world performance assessment of sustainability solutions such as smart sensor systems, rainwater harvesting systems, wastewater reclamation systems, ultralow water use appliances, and photovoltaic panel systems. The related mains water and grid electricity savings, operational and repair costs and payback periods for capital expenditures were collated. Interviews with building managers provided insight into asset management challenges. Recurring themes from the case studies were the high costs of rainwater harvesting systems, and significant water savings opportunities via better management which were revealed by consumption monitoring. In the Indian case study, better water management to address leakage, and more drought-tolerant landscaping in a semi-arid climate, could reduce blue water use by up to 52% and reduce operational costs by up to 23%. In the UK student accommodation case study, up to 50% of potable water use was caused by malfunctioning toilets. In the UK mixed use building case study (office/teaching/laboratory), significant performance gaps of green building assets arose from technical and social issues (pump failures, leakages, poor alignment of demand and supply with limited storage, low photovoltaic panel efficiency, poor user acceptance, etc.), but the consequences were exacerbated by inadequate asset management that resulted in long system downtimes. Overall, it was concluded that better monitoring, maintenance, and management are the most cost-effective ways of improving water use sustainability in the built environment