Metrics for wise water management earns award for ASU doctoral student

Arizona State University engineering doctoral student Elizabeth Martin is a winner of a Central Arizona Project  (CAP) 2012 Award for Water Research.

The award recognizes excellence in graduate or undergraduate research in areas related to water challenges facing Arizona, California and Nevada. CAP is the steward of the largest resource of renewable water supplies in Arizona.

Martin is pursuing her doctorate in civil engineering through the School of Sustainable Engineering and the Built Environment, a part of ASU’s Ira A. Fulton Schools of Engineering.

Her second-place award from CAP was based on her research paper “Value Intensity of Water Used for Electrical Generation in the Western U.S.; An Application of Embedded Resource Accounting.”

Martin is doing the research under the direction of assistant engineering professor Benjamin Ruddell, who is her doctoral studies faculty adviser. The winning paper describes Martin’s examination of the water challenges likely to increase with the expected impacts of climate change and growing demand for water.

Available water supplies will be affected by increasing temperatures and evaporation, decreased rainfall, and more intense droughts in the Southwest. At the same time, as population and industry continue to grow, resource demands will increase and become more concentrated around urban areas – particularly demands for electrical energy.

Water resources are critical for electrical energy production. In the United States, a larger percentage of water is withdrawn from supply sources for electrical energy production than for any other single purpose.

Climate change coupled with growing demand for resources means that “reallocation of water supplies, in addition to the redistribution of the production of electrical energy and other resources, will be necessary to adapt reduced supplies to meet changing resource demands,” Martin says.

Her research explores the “water-energy nexus” in terms of water-for-energy – or the amount of water “embedded” in electricity – meaning the water consumed in the process of generating electricity.

“We combine this information with retail prices paid for electricity, and evaluate it over the electricity trade network within the western United States,” Martin explains.

The results are a network of resource flows (flows of electricity, currency, and embedded water) across the region.  This allows for determination of a “value intensity” of the water embedded in electricity.

“Value intensity is not a price of the embedded water, but a metric we can use to identify patterns in changes of value intensity of embedded water resulting from electricity trade on the power grid,” she says.

These patterns of change in the value intensity, caused by the trade in electricity, provide useful information.

The results of this analysis show that “an implicit trade in embedded water appears to exist in the western United States, and that this trade appears to benefit both importing and exporting states because exporters increase and importers decrease the value intensity of water embedded in traded electricity,” Martin says

This information, and the methodology used to obtain it, can be used to help managers of water and energy systems adapt to changing climate conditions and growing demand.

Her analytic methods can also help establish value intensities of resources other than water, and can be applied to small-scale or large-scale resource systems.

Her CAP award includes a $500 prize and the opportunity to present her research at the Arizona Hydrological Society Annual Symposium in September, where she will be formally presented the award.

Martin's paper will be published in the conferences proceedings journal and on the CAP website.