The Environmental Cost of Electricity

>> Aug 25, 2010

You probably check your utility bill monthly to find out how much your television, toaster, computer and refrigerator are costing you to run.  

The question you should also be asking yourself is: how much does my energy cost in terms of the natural world? Because thermoelectric power plants, be they nuclear, coal, natural gas, or oil, create varying amounts of pollution, and use vast quantities of water  . In fact, almost 40 percent of freshwater withdrawals   in the U.S. are the result of power generation. 

Thermoelectric power plants are those plants which burn a fuel to create steam to drive a turbine, which in turn spins a generator to create electricity. But “green” energy sources are not exempt, either. From hydroelectric through geothermal and solar thermal, water use rises, culminating in solar thermal technologies. Even traditional silicon solar photovoltaic (PV) panels use water in their manufacture, and additional water in cleaning, especially in a large field array.  

cwi Included in this water use is the amount of water   needed to extract and process the various fuels, from natural gas through tar sands to fuel ethanol and biodiesel.  

There can never be too much said about the pollutive effects of power generation, but most people are now aware of these issues, from the toxicity of burning coal to the residual land effects of producing uranium – not to mention the Chernobyl-type effects when we lose control of the fission genie.  

Yet few people consider power generation’s effect on water, even though the typical, 500 megawatt coal-fired power plant uses about 2.2 billion gallons of water   each year. This is enough to serve the needs of a city of 250,000, and causes the deaths of about 21 million fish eggs, fish fry and fish larvae as the tiny creatures are drawn through the pumping equipment and expelled dead in heated water at the end of the process.  

In addition, according to the U.S. Environmental Protection Agency, up to 1.5 million adult fish die as a result of getting trapped against intake screens, where pump pressure acts like a suction device, preventing fish from swimming and moving their gills, thus literally drowning them.  

This water use is so extensive and pervasive that one scientist for the Virginia Water Resources Research Center calculated that 1 kilowatt-hour of electricity uses 95 liters (25 gallons) of water. One kilowatt-hour is the amount of energy it takes to run your coffeemaker   for a month, though the actual water used to make that coffee is only 15 gallons (8 cups per day over 30 days, based on 16 cups in a gallon).  

Now, at the beginning of the 21st century, with the world on the cusp of climate change and dwindling fresh water resources, it’s time to realize that our “electric agenda” is profligate, and we need to find ways to cut back this aspect of modern civilization if the planet is to survive us.  

There are ways to use less water, even without ditching the existing infrastructure, and in New York State the Department of Environmental Conservation is looking at   some of those ways. Called, “Best Technology Available for Cooling Water Intake Structures”, the study   scrutinizes the “once-through” cooling systems on 25 power plants operating within the state.  

cwi2 These systems take in huge amounts of water, use it to produce steam and cool the plant’s equipment, then dump the heated water back into a lake or river, where the water’s elevated temperature and lowered oxygen levels seriously impact aquatic populations.  

They do this because, when these power plants were being built, no one really thought about fresh water as a finite resource. Now, when it’s painfully apparent what a short leash mankind is on in terms of potable water, the problem is going to cost more to fix than it would have to prevent; about $8.5 billion more, to be exact.  

The state has, however, added several caveats to its retrofit demand. One exempts power plants which can’t accommodate onsite cooling towers; another exempts peaking plants and other power plants that traditionally have supplied only a modest amount of power (15 percent or less); and there is a final exemption for plants where the cost of converting to closed-loop is “wholly disproportionate” compared to any water conservation benefits derived.  

The latter exemptions are not New York’s way of favoring power plant owners, however. They are aimed at the 6.5 million electric consumers, who would end up paying exorbitant electricity rates if the exemptions weren’t provided, since most power plant infrastructure costs are passed on to consumers as higher rates, and not taken out of the dividends of shareholders.  

New York electricity consumers grumble, but like the rest of us they need to realize that we have benefited from cheap power for a very long time, and now the fiddler – in the form of Mother Nature – is holding out the hat.

Source: celsias,  Jeanne Roberts

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