The Complex Relationship and Looming Crisis Between Our Thirst For Water and Our Hunger for Energy
July 3rd, 2012
Via Think Progress, another look at a recent report on the watergy nexus:
The 20th century was characterized by the frenzied acquisition, storage, and use of oil. But many experts believe that the 21st century will be remembered as the century of water.One of the most alarming emerging issues is the symbiotic — and often conflicting — relationship between electricity generation and water.
A new report called “Burning Our Rivers: The Water Footprint of Electricity” details this relationship, illustrating the massive amounts of water resources used for electricity generation — particularly from fossil fuels and nuclear.
An average U.S. household’s monthly energy use (weighted by cooling technology and fuel mix) requires 39,829 gallons of water, or five times more than the direct residential water use of that same household…. Electricity—as we generate it today—depends heavily on access to free water. The impact to our freshwater resources is an external cost of electrical production. What the market considers ‘least cost’ electricity is often the most water intensive.
According to the U.S. Geological Survey, 53 percent of all the fresh surface water withdrawn for human consumption in 2005 was used for electricity generation.
While consumption in the U.S. is falling, coal is still the most dominant source of power in the country. It is also the single largest consumer of water resources:
A MWh of electricity generated by coal withdraws approximately 16,052 gallons and consumes approximately 692 gallons of water…. On average (a weighted average taking into account the current mix of cooling technologies being used at coal plants in the U.S.), coal-fired electricity requires the withdrawal of approximately 13,515 gallons and the consumption of 482 gallons of water per MWh for cooling purposes.
The water not used directly for power generation is used in mining coal and other treatment before burning, creating millions of gallons of “sludge” that can potentially pollute freshwater supplies.
Nuclear power is not much better:
Similar to coal-fired power plants, nuclear power plants traditionally operate with single-cycle cooling technologies, which are systematically more water intensive than all other thermodynamic cooling technologies. Additionally, because nuclear fission is less thermodynamically efficient than the combustion of coal, the water required to generate nuclear power is slightly greater than that of coal-fired power.
According to the report, Nuclear power plants “(withdraw) approximately 14,881 gallons and (consume) 572 gallons of water per MWh.” Large amounts of water are also used in the uranium mining process and for storage of fuel rods. In Georgia, for example, two large nuclear power plants use more water than all the water used by people living in Atlanta, Augusta and Savannah combined.
Non-fossil fuel power alternatives offer some hope for decreasing our water consumption. Increasing the penetration of photovoltaic solar and wind power “to 40% of the grid would … reduce consumptive water use by 11%.” However, we must be careful not to assume that all green power sources are water efficient. “Every day, approximately 9 billion gallons of water— enough to meet the daily demands of more than 50 million Americans—evaporates from reservoirs behind hydroelectric dams.”
Water and energy are mutually dependent resources. There will always be trade-offs for various energy technologies. But if we want to get serious about reducing our demand for precious water resources, we need to transition away from the most water intensive resources.
This entry was posted on Tuesday, July 3rd, 2012 at 7:52 pm and is filed under Uncategorized. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
Leave a Reply
You must be logged in to post a comment.
Educated at Yale University (Bachelor of Arts - History) and Harvard (Master in Public Policy - International Development), Monty Simus has held a lifelong interest in environmental and conservation issues, primarily as they relate to freshwater scarcity, renewable energy, and national park policy. Working from a water-scarce base in Las Vegas with his wife and son, he is the founder of Water Politics, an organization dedicated to the identification and analysis of geopolitical water issues arising from the world’s growing and vast water deficits, and is also a co-founder of SmartMarkets, an eco-preneurial venture that applies web 2.0 technology and online social networking innovations to motivate energy & water conservation. He previously worked for an independent power producer in Central Asia; co-authored an article appearing in the Summer 2010 issue of the Tulane Environmental Law Journal, titled: “The Water Ethic: The Inexorable Birth Of A Certain Alienable Right”; and authored an article appearing in the inaugural issue of Johns Hopkins University's Global Water Magazine in July 2010 titled: “H2Own: The Water Ethic and an Equitable Market for the Exchange of Individual Water Efficiency Credits.”