A recently published report reveals that water managers across the country are missing significant opportunities to save water, energy, and ultimately money. The report, 'Water and Energy Nexus: A Literature Review,' published by Water in the West, a center for water research based at Stanford University, examines how much water is used to extract natural resources such as coal, oil and natural gas, as well as the amount of water used to generate power.

According to co-author Cynthia Truelove, a research associate at Stanford Woods Institute for the Environment, the report highlights “robust opportunities for reductions in greenhouse gas emissions, as well as for the conservation of scarce water resources, coupled with the potential for generating significant new renewable energy resources.”

The report is a comprehensive review of papers and reports that focus on government policy, together with scientific and technical research on the link between water and energy, published by academic institutions, government departments and non-profit organizations over more than two decades between 1990 – 2013.

“This report summarizes the tremendous breadth and depth of research and analysis that have explored the interrelationship between water and energy,” said Andrew Fahlund, executive director of Water in the West. “Nevertheless, it also points out a number of significant gaps in our understanding of the nexus of water and energy and points to important needs for future study.”

The report is comprised of two main sections: 'Energy for Water,' which examines energy consumed by the water and wastewater sectors, and 'Water for Energy,' which assesses water use by the energy sector. The report adopts a full life-cycle approach to illustrate the fundamental connection and interdependency between water and energy – water is essential for energy production, and energy is essential for water delivery.

Key Findings

1. Current water and energy management regulations make it exceedingly difficult to assess the substantial amount of power and natural gas used to extract, convey, treat and distribute drinking water across the US. While California has been pressing water managers to use energy more conservatively – and is the only state to do so – local regulations are still a stumbling block. Presently California uses 19% of its power and over 30% of its natural gas supply for extracting, treating, and distributing water, which presents a significant opportunity to conserve energy.
2. The assumption that fuels with lower carbon emissions are better for the environment may be unsound. While natural gas is thought to burn cleaner than fossil fuels, a significant amount of water is used during the fracking process to extract this gas, and the impact on water resources – both in terms of quantity expended and the impact of potential contamination to the quality of water resources – has not been adequately assessed.
3. Managers in the water and wastewater sector could feasibly generate substantial amounts of renewable energy, which will enhance the reliability of the power grid in states such as California. By restructuring energy tariffs and applying transmission regulations, together with the implementation of innovative methods of water and wastewater treatment, the water sector could be encouraged to significantly enhance its capacity to generate renewable energy sources from hydro, wind, solar, biomass or biogass.
4. The report highlights a number of areas that future research should focus on, including:

• the water demands of emerging technologies – noteably hydro-fracking;
• energy saving opportunities that can be realized from water treatment and distribution systems;
• technological innovations that could facilitate the extraction of energy from wastewater;
• Marketing mechanisms that would allow for more cost-effective water trading and transactions.

Download the full report: "Water and Energy Nexus: A Literature Review".