Solar energy will not burden Arizona’s water resources in the foreseeable future, according to research presented by University of Arizona experts.

Three researchers discussed solar energy and its effects on local water resources, "A Drop in the Bucket: Making the Connection between Solar Energy and Water Use in Arizona," last week at the Yuma Agricultural Center Auditorium.

Gregg Garfin, a member of the UA School of Natural Resources and the Environment, explained the reason for the "research hits the road" discussion is because he has encountered "people concerned with drought and solar energy and how much water it will suck up."

Data indicates a developing dry period coupled with long-term increases in temperatures. "With that we see a greater demand for energy," Garfin said.

Research also shows water availability in 2060 in the Southwest (Arizona, New Mexico and southern Nevada) will be 20 percent below today’s water availability, noted Ardeth Barnhart, program director for renewable energy at the UA Institute of the Environment.  In addition, Arizona is one of the fastest-growing states, with a projected 10.7 million population by 2030.

"An increase in population means an increase in demand for energy," Barnhart said. But solar technology is very costly. "That’s why we don’t see a lot installed in Arizona," she said.  So why the sudden interest in solar technology when it’s so expensive?

The Arizona Corporation Commission approved a Renewable Energy Standard in 2006, requiring regulated electric utilities to generate 15 percent of their energy from renewable resources like solar and wind by 2025.

Not surprisingly, studies show that Arizona is ideal for solar technology, not only because it’s sunny but because of access to high-voltage transmission lines.

This could have a positive impact on economic development if the state met its own energy needs and imported unused energy, Barnhart said.

George Frisvold, a professor and extension specialist with the UA Department of Agricultural and Resource Economics, noted that meeting the 2025 renewable energy standard will require a "negligible share" of Arizona’s consumptive water use.

As an example, said Frisvold, concentrating solar power (CSP) trough technology typically uses a high volume of water in comparison to other solar technologies. He said if only CSP is used, it would require 35,000 acre-feet of water in 2025 to meet Arizona’s standard, 0.5 percent of current demand.

Noting that one teaspoon equals .4928 percent of a liter, "if Arizona’s current water use were represented by a two-liter bottle of water, CSP water use would only reach two teaspoons by 2025."

Two solar projects are located in the region. In Gila Bend, the Abengoa "Solana" plant uses 75 percent less water than the farm it replaced. The Agua Caliente solar project in Yuma County is under construction on 2,400 acres of former farmland. Frisvold also noted that water is needed to produce energy and energy is needed to get water. "It’s nothing new. It’s an age-old problem."