Decision-making at the Water-Energy Nexus

UV Disinfection at Seymour Capilano Filtration Plant, Vancouver BC

Energy considerations represent a major area of concern that must be addressed by water service providers if they hope to sustain current levels of service to customers. The ability of urban water systems to provide water services is currently being challenged by a range of factors including: population-driven escalation in demand; pressure on traditional water sources due to pollution, over-extraction, climate variability, and competing demand from other sectors; more stringent environmental regulations; and volatility in energy supply and prices. Whereas many water providers exercise strict control over water supplies, water quality, water treatment, and water operations, few manage energy as rigorously despite significant energy consumption and costs. Urban water systems require substantial energy inputs, and most new water supply solutions and treatment technologies involve additional energy inputs. Energy is required for all stages of the urban water cycle, from the collection, pumping, and treatment of drinking water to the transmission and distribution of supply to customers and the collection and treatment of wastewater. Energy use in the water and wastewater sector will grow by 40 percent over the next 20 years, driven by new regulations and population growth. Moreover, the anticipated introduction of energy-intensive technologies, such as desalination, will further increase energy use.

Energy considerations are also present when resolving problems such as providing safe drinking water, generating power with low greenhouse gas emissions, and managing ecosystem needs. Provincial and Federal greenhouse gas reduction goals create conflicting water allocation priorities. For instance, between promoting independent hydroelectric power projects and managing environmental impacts for rivers and streams. Underlying this issue of water management is governance and how to prioritize water allocations to meet conflicting community goals. Greenhouse gas mitigation and adaptation to global climate change are emerging as two of the most pressing issues facing Canadian water managers. Energy is now a key decision factor for managing water allocations and climate change has the potential to negatively affect both energy and water availability as many communities struggle to meet growing clean energy demands while facing uncertainty about the adaptability of aging water and wastewater infrastructures.

The water sector tends to prioritize water allocation and drinking water protection, so energy management efforts typically aim to minimize the large energy consumption in these two areas. Service providers balance competing goals in trying to achieve increasingly stringent water quality standards, while at the same time aiming to reduce energy consumption. However, climate change, uncertainty of supply, and recent greenhouse gas policies have prompted new research in water-energy decision-making, water-energy generation impacts, customer water use and its affect on energy/greenhouse gas emissions in urban water systems, and institutional arrangements between energy providers and water service providers.

Steve Conrad, chair of the Water Research Group, is currently leading research about utility energy decision-making. As principal investigator, under contract to EMA Inc, for the Water Research Foundation project 4090, he lead a multinational team researching the development of an energy management decision support system to help water utilities manage the complex trade-offs involved in sustainable energy management. Working with the Australian Commonwealth Scientific and Industrial Research OrganisationNational Center for Atmospheric Research, and New York State Energy Research and Development Authority, the research team is developing methodologies to identify economic, environmental, and social issues regarding water-energy management, and necessary parameters and methods for analysis of energy management options. Special attention is being given to developing approaches that incorporate climate and greenhouse gas emission policies into the decision support system. 

A final report is available by request to Steve Conrad or from the Water Research Foundation. Steve recently published a synopsis on decision-making at the water-energy nexus in:
Conrad, S. 2012. “Decision-Support for the Water–Energy Nexus: Examining Decision-making in the American West” in Kenney, D. The Water-Energy Nexus in the American West.