Understanding the Crucial Connection Between Water and Energy
A number of prominent water scientists and activists—prominently including the Pacific Institute’s Peter Gleick and Columbia Water Center’s own Upmanu Lall— have for some time called attention the crucial link between the global water and energy issues.
But while awareness of the water-energy nexus is growing, in many parts of the world policy affecting both energy and water remains shortsighted at best and dangerously counterproductive at worst.
Here are some of the myriad ways in which water and energy use are intimately interlinked, what it means for the global sustainability movement, and what can be done.
The way we use water consumes energy.
In the United States, about 4 percent of power generation is used for water supply and treatment, according to a report from Sandia National Laboratories to Congress; domestic hot water heating accounts for some 9 percent of domestic energy use.
However, the amount of energy that goes to water use varies considerably from region to region. In California, for example, moving, cleaning and heating water around accounts for a 19 percent of the state’s electricity consumption and 30 percent of its natural gas. Southern California in particular pumps substantial amounts of water from great distances to meet local water demand.
Given both the emerging constraints on global energy production and climate stress caused from burning fossil fuels, it would makes sense to both conserve water and do whatever we can to make water use less intensive.
Unfortunately, many proposed solutions for acute water shortages around the world are actually much more energy intensive than what we are currently doing. For example, governments from California to Israel to Saudi Arabia are turning to massive desalination projects as a holy grail to solve persistent water problems. But as a 2007 report by the California Public Utilities Commission pointed out, “Producing fresh water from sea water by desalination is a highly energy intensive process and should be utilized only when no other economical water supplies are available.”
According to the commission, Catalina Island, off the coast of Southern California, produces 25 percent of its fresh water from desalination–but that same desalination accounts for nearly 70 percent of the island’s energy use.
Other high-energy solutions include pumping water from distant places. The Southern Nevada Water Authority, for example, has plans to build a 285-mile pipeline to pump water to parched Las Vegas, a desert city in a drought that gets most of its water from quickly sinking reservoirs fed by the Colorado River. Pumping water over long distances is extremely energy intensive.
Conventional energy production is crucially dependent on abundant supplies of freshwater.
Thermoelectric water use—essentially, the boiling of water to turn turbines to make electricity or using water to cool power equipment—accounts for a stunning half of total water withdrawals in the United States. The vast majority of electricity generation comes from these steam driven turbines, whether one is using coal, natural gas, oil or nuclear fuel to heat the water.
Once used, power plants release whatever water has not been lost to evaporation back into the environment—at a much higher temperature, a practice which can seriously damage the ecosystems of waterways.
But that’s not the only problem. It turns out that the extreme water-intensity of thermoelectric production means that that water needs could easily collide with energy demands in coming years. In a 2009 article for the Columbia Journal of Environmental Law, Benjamin K. Sovacool and Kelly E. Sovacool made the case that the convergence of population growth, rising electricity demand and drought in some areas “could threaten to cause massive shortages of water, while forced shutdowns could occur due to lack of water in others.”
Yet, “despite the seriousness of water concerns associated with electricity use, most electric utilities continue to propose water-intensive power plants as the best way to meet demand projections.”
The other major source of electrical energy that is threatened by water shortages is hydroelectric. Some 20 percent of the world’s electricity comes from large-scale hydroelectric dams—dams that require steady, large flows of water.
But as the world climate and water cycles are disrupted, energy from large hydroelectric plants is threatened. To give just one example, low water levels at Lake Mead threatens to shut down power at the Hoover Dam, a major source of electricity for Las Vegas and Southern California.
The risk to electricity from diminishing water is a global problem. In the Philippines this summer drought caused the National Grid Corp to cut electricity in half in some areas as reservoir levels fell to unprecedented lows.
Meanwhile, a study from Switzerland predicts that Alpine glacier melt could cause steep declines in hydroelectric power there—from nearly 60 percent now to 47 percent in 2035.
India and other countries that get substantial power from the glacier-fed rivers of the Himalayas is also at risk.
The quest for new sources of cheap, abundant energy threatens existing water sources.
We have known for years that reckless coal mining contaminates ground and surface water. We all know that coal is a dirty fuel, however; but what about “clean-buring” natural gas? Recent advances in hydraulic fracturing (hydrofracking) technology have created the potential for industry to exploit vast, previously untapped reserves of natural gas across the United States and the world.
But as the recent documentary Gasland showed, hydrofracking presents a serious risk to water, as the millions of gallons of water, sand and toxic chemicals it takes to frack a well seep to the surface, poisoning the ground and surface water of surrounding communities.
In Canada, meanwhile, the mining of oil sands has become a major source of “non-conventional” crude oil, touted as a way to offset declines in conventional oil production. But in addition to other problems, producing oil sands consumes tremendous amounts of water, mostly diverted from the Athabasca River.
Oil shale, frequently touted as another vast, non-conventional oil resource of the future, would also require staggering amounts of water to produce. Given that most oil shale in the U.S. lies in already water-stressed regions and would rely on heavy withdrawals of water from the already drying-up Colorado river, it is difficult to see how a collision between water needs and energy can be avoided here as well.
Finally, the seemingly unending cascade of oil spills, large and small, threaten freshwater resources and seawater alike—from Newtown Creek in the heart of New York City, poisoned by a 17-30 million gallon oil spill 57 years ago to the Deepwater Horizon, to the recent spill in Michigan.
It’s not just fossil fuels that threaten water, though. Even something as seemingly benign as corn-based ethanol requires tremendous amounts of water to grow—not a sustainable solution for parts of the country that depend on irrigation from fossil aquifers like Ogallala of the Great Plains.
Use of fossil energy is warming the climate—which disrupts the water cycle and threatens both water and energy resources.
Insofar as much climate can be described as largely the form and movement of water over the earth, climate change can also be seen as fundamentally a water issue, manifesting in strong storms, more drought, and rising sea levels (all hydrological issues).
Climate change, therefore, is likely to add additional pressure to both water and energy resources.
What is to be done?
Of all energy sources, photovoltaic solar power and wind generation by far depend the least on water consumption to produce; according to the American Wind Energy Association, wind power uses 1/500th as much water as coal per unit of electricity produced.
But more important than switching energy sources is curtailment and conservation—of both energy and water consumption. Given the connection between water and energy, it follows that lowering our collective carbon and non-renewable energy footprint is one of the best ways to protect water resources; similarly, cutting water consumption is a key way to cut our carbon and energy footprints.
Such solutions don’t depend only on the actions of individuals, but can easily be seen as functions of policy as well.
For example, in Gujarat, India, electricity for farmers is subsidized to such a degree that both water and energy consumption is practically free—a serious problem for a country that by all accounts faces acute water shortages in the coming years.
One project of the Water Center’s key projects involves examining the subsidy structure for the state’s electricity to see if, in concert with water-saving technology and crop selection, the subsidy can be altered to give farmers incentives to conserve both water and energy.
But India is not the only place that can benefit from a dual energy/water saving strategy. Erica Gies of the New York Times reports that from 1993 to 2006, the Santa Clara Valley Water District “saved approximately 1.42 billion kilowatt-hours of energy, equivalent to the annual power used by 207,000 households, through financial incentives, advisory programs and infrastructure investments that cut water consumption.”
It would seem, then that the most important step is simply one of awareness—to recognize that the energy-water nexus is ever-present, and to design both water and energy solutions with the entire system in mind.
Today is Blog Action Day, and the issue is water.