Performance assessment and life cycle analysis of potable water production from harvested rainwater by a decentralized system
Journal of Cleaner Production
Open access. Under a Creative Commons license: https://creativecommons.org/licenses/by/4.0/
Decentralized rainwater harvesting (RWH) from roof runoff can complement the centralized supply of mains (drinking) water for a range of contexts, to assist in alleviating issues of water security. However, treatment to potable standard of harvested rainwater is not widespread. Consequently a comparative life cycle analysis (LCA) of decentralized and centralized potable water supply has not previously been undertaken. In this paper we describe a novel point-of-use (POU) treatment device, which was used to treat harvested rainwater to potable standard. We then provide a performance assessment for this system and an LCA with a comparison to centralized supply. Results of the performance assessment indicate a water saving efficiency (E T ) of between 0.6 and 100%, depending on rainfall (0.6 from April when rainfall was significantly below average). This highlights that the POU device was able to deal with the scale of roof runoff supply originating from a RWH system at a commercial building scale. The LCA results suggest that potable water produced from this decentralized RWH POU system currently performs more poorly than centralized water from an environmental perspective. Its impacts in most categories would be significantly reduced if the electricity consumed by the system were supplied from a renewable source such as solar PV or wind turbines instead of the UK grid. Priority should be given to optimizing the energy efficiency and exploring opportunities for combined use with renewable energy technologies in order to improve the environmental performance of POU treatment devices.
This research was funded by the European Commission’s Eco-Innovation programme (ECO/12/332899) and supported by Ozone Industries Ireland Ltd, the University of Exeter, Flextronics International, Greenlife and Kiwa.
This is the final version of the article. Available from Elsevier via the DOI in this record.
Published online 25 November 2017