Tuesday, May 5, 2009
The Energy-Water-Technology Triangle - Part I
Energy and water. The two are inextricably bound because the generation of the former requires a staggering volume of the latter. And getting maximum power from the least amount of water while producing effluents that meet acceptable government standards -- that's a monumental task, demanding technologies which don't currently exist.
In 2000, thermoelectric power generation in the United States used 195,000 million gallons of fresh water per day - that's enough to supply Ann Arbor, Michigan, with drinking water for more than 30 years. In addition to using vast supplies of fresh water, power plants consume energy as they bring the water from the source. In other words, it takes energy to make energy.
Furthermore, pollutants build up in a power plant's boilers and cooling systems, creating highly saline solutions. If the plant discharges that water into a lake or river, the contaminants could harm fish and plants. At the same time, burning fossil fuels to generate electricity releases greenhouse gases that acidify bodies of water and can affect air quality hundreds of miles away. If rain falls on coal stored in piles outside power plants, the runoff can wash out heavy metals, such as arsenic and lead, and carry them into nearby bodies of water or into the ground water. To say that the interrelated problems are complex is an understatement.
University of Michigan engineering professors Peter Adriaens and Christian Lastoskie have put together a team to take on water-energy challenges.
"Technology is key," Adriaens said. "But supplying the energy grid in a sustainable manner is equally an issue of public health, business entrepreneurialism, environmental law and public policy - they're all aspects of the problems and solutions associated with water and energy. The University of Michigan is traditionally strong in all of those areas, so we're well-equipped to address the issues. And they're important issues. It's no exaggeration to say that sustainable economic growth depends on solving the problems related to the energy-water connection."
The competition for fresh water is fierce - thermoelectric generation uses 40 percent, agriculture devours another 40 percent, and about 20 percent finds its way to other segments, all of which are integral to daily life. This competition will become even more ferocious as energy demands increase and freshwater water supplies shrink, and the population not only grows but migrates to the southwest United States, where water is already scarce. Plus, environmental regulations will become more stringent, leading to new constraints on the operation of existing power plants and the construction of new ones.
"The problems become more dramatic when you consider that, by the year 2020, our population will require an additional one hundred and fifty new high-output power plants," Adriaens said. "So we're looking at an elaborate scenario in which we'll need innovative water technologies, new environmental restrictions, new public policy and legal approaches, and an energy model that provides incentives for the power industry to continue evolving, improving its output and efficiency - it's unfortunate, but once a facility achieves a certain performance standard, there currently is little incentive to become even more productive and efficient."
The issues are significant and a comprehensive program is required to address them.
Part II: The Energy-Water Nexus Program