"U.S. citizens may indirectly depend upon as much water turning on the lights and running appliances as they directly use taking showers and watering lawns." Sandia National Laboratories
The water requirements of energy production, whether for coal-fired power plants, biofuels, or other energy sources, are receiving increased attention as society grapples with the complex problem of meeting our growing energy needs in a sustainable way.
"Right now, we're on the cusp of real change so if we're going to reinvent ourselves, people are saying let's be a little smarter about it," says John Pellegrino, a CU-Boulder research professor involved in the Environmental Engineering Program.
That means considering the water use of our energy options using life-cycle analysis and coming up with new ways to recycle water quickly and reduce the overall water requirements through new technologies.
To this end, CU-Boulder's Environmental Engineering Program has introduced a new Energy Option for undergraduates. The curriculum, which includes courses from several different engineering disciplines, is generating a lot of interest among students.
"I believe that if we can change how we use and make energy, this transition to a green energy economy will have the greatest impact on the environment going forward," says undergraduate Kitty Stevenson. Noting that the curriculum includes the study of solar, wind, algae, hydrogen, geothermal, and many other potential forms of energy, she says, "The EVEN energy option allows me the greatest overview of what our energy future may look like. " The most recent data from Sandia National Laboratories indicate that electricity production from fossil fuels and nuclear energy requires 190 billion gallons of water per day, accounting for 39 percent of all freshwater use in the nation. The problem is projected to increase due to population and economic growth, with some regions like the desert Southwest facing a particularly dire forecast of water shortages.
Advanced cooling technologies for thermoelectric power plants are needed, along with renewable electric power to minimize water usage. Wind, solar-photovoltaics, air-cooled geothermal, run-of-river hydroelectric, and oceans energy systems can play important roles as they consume no fresh water during operation, according to the U.S. Department of Energy's December 2006 Report to Congress.
Some other alternative fuels, such as corn ethanol, biodiesel made from soybeans, and hydrogen (especially that produced through natural gas steam reformation), currently have high water requirements although that could change in time.
"These benchmarks will change if we do things right," Pellegrino says. If biofuels can be produced from crop or forestry waste, switchgrass, or algae, for example, the potential reduction in water use will be great. But such factors as location, processing methods, and infrastructure will make a great differenceall areas where environmental engineers can complement the work of other energy experts to decrease our environmental footprint. Pellegrino has supervised a number of undergraduates through the college's Discovery Learning Apprenticeship Program in research on polymer membranes that could be used in the production of biofuels from corn stover and other cellulose-rich waste materials. The research aims to develop methods to recover multiple parts of the mixture for various purposes and to recycle the water and electrolytes back to the waste conversion process.
Students in Professor Angela Bielefeldt's freshman environmental engineering course, meanwhile, are studying ways to turn municipal solid waste into energy, such as using anaerobic digesters to produce methane or hydrogen from wastewater and animal manure. And some senior design teams are working on design upgrades to water treatment plants that will minimize energy consumption.
In addition, Halliburton, a U.S.-based oilfield services corporation with operations in more than 70 countries, is sponsoring a college-wide design competition this spring in which it is offering scholarships to the student team that can propose the best solutions for meeting the world's future energy demands while maintaining the smallest environmental footprint possible.