Resilience assessment insights based on the energy balance in drinking water networks

Abstract

The current paper primarily discusses the interconnection between water, energy and resilience, revisits the energy balance, proposes a modified calculation approach and metrics to assess system resilience criteria: energy efficiency and service flexibility. A sensitivity analysis is carried out considering: i) reference elevations, ii) levels of water losses, iii) contribution of shaft energy and pumping groups and iv) impact of water and energy efficiency improvement measures. The modified approach provides a realistic energy balance, while the original approach provides an ideal (no water losses) energy balance. Both approaches provide similar information for surrogate resilience metrics, but offer complementary information for the surplus energy index. Energy in excess per authorised consumption is most suitable to evaluate energy efficiency. Both the ratio between surplus energy and energy in excess and the surplus energy index are complementary in assessing service flexibility. Water and energy efficiency improvements should contribute to energy efficiency, ensuring service flexibility.