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http://www.nytimes.com/2011/06/08/opinion/08bryce.html?hpwhttp://www.blogger.com/img/blank.gif
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IN April, Gov. Jerry Brown made headlines by signing into law an ambitious mandate that requires California to obtain one-third of its electricity from renewable energy sources like sunlight and wind by 2020.
But there’s the rub: while energy sources like sunlight and wind are free and naturally replenished, converting them into large quantities of electricity requires vast amounts of natural resources — most notably, land.
Consider California’s new mandate. The state’s peak electricity demand is about 52,000 megawatts. Meeting the one-third target will require about 17,000 megawatts of renewable energy capacity. Let’s assume that California will get half of that capacity from solar and half from wind. Most of its large-scale solar electricity production will presumably come from projects like the $2 billion Ivanpah solar plant, which is now under construction in the Mojave Desert in southern California. When completed, Ivanpah, which aims to provide 370 megawatts of solar generation capacity, will cover 3,600 acres — about five and a half square miles.
The math is simple: to have 8,500 megawatts of solar capacity, California would need at least 23 projects the size of Ivanpah, covering about 129 square miles, an area more than five times as large as Manhattan.
Wind energy projects require even more land. The Roscoe wind farm in Texas, which has a capacity of 781.5 megawatts, covers about 154 square miles. Again, the math is straightforward: to have 8,500 megawatts of wind generation capacity, California would likely need to set aside an area equivalent to more than 70 Manhattans. Apart from the impact on the environment itself, few if any people could live on the land because of the noise (and the infrasound, which is inaudible to most humans but potentially harmful) produced by the turbines.
Unfortunately, energy sprawl is only one of the ways that renewable energy makes heavy demands on natural resources.
Consider the massive quantities of steel required for wind projects. The production and transportation of steel are both expensive and energy-intensive, and installing a single wind turbine requires about 200 tons of it. Many turbines have capacities of 3 or 4 megawatts, so you can assume that each megawatt of wind capacity requires roughly 50 tons of steel. By contrast, a typical natural gas turbine can produce nearly 43 megawatts while weighing only 9 tons. Thus, each megawatt of capacity requires less than a quarter of a ton of steel.
Such profligate use of resources is the antithesis of the environmental ideal. Nearly four decades ago, the economist E. F. Schumacher distilled the essence of environmental protection down to three words: “Small is beautiful.” In the rush to do something — anything — to deal with the intractable problem of greenhouse gas emissions, environmental groups and policy makers have determined that renewable energy is the answer. But in doing so they’ve tossed Schumacher’s dictum into the ditch.
Published Letter Responses From This Article:
ReplyDeletehttp://www.nytimes.com/2011/06/14/opinion/l14energy.html?hpw
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The toll that fossil fuels take on our health, economy and climate has been devastating.
Especially as technology evolves, it would be a horrible mistake to ignore the tremendous job-creating potential that exists in developing clean energy like wind and solar....
Presenting false choices about renewable energy will only distract us from the important task that lies ahead. --VANESSA PIERCE
Deputy Director, Sierra Club’s Beyond Coal Campaign
Farmers and ranchers around the country till fields and graze cattle amid the wind turbines on their land. Each turbine takes up a quarter of an acre. If California used today’s 3-megawatt turbines, it would need an area about the size of Central Park to site 8,500 megawatts of power — hardly equal to 70 Manhattans. And it would create enough power for about 2.5 million California households.
Mr. Bryce also compares the steel demands of wind- and gas-based power. He does not mention gas-based electricity’s share of the 800,000-plus miles of steel pipes used for gas drilling and transporting gas to market.
Wind turbines recover their full life-cycle energy inputs within the first seven months of operation. --PHILIP WARBURG, author of the forthcoming book “Harvest the Wind.”
We do not need vast new tracts of land to install solar and wind power. We have acres and acres of buildings that are perfectly situated for rooftop collection systems and “small wind” generation.
Not only does this avoid the disturbance of new land but it also generates the power in the same location as it is consumed, avoiding the need for long-distance transmission, with its inherent power loss and ecological footprint issues. --GUY GUIER
Mr. Bryce’s cost-benefit analysis does not take into account the cost of nonrenewable fuels themselves. For example, natural gas turbines might be cheap to build, but running them requires a constant supply of natural gas, which is costly, and will only become more costly as it becomes more scarce. On the other hand, operating solar panels requires only sunlight.
Regardless, the cost issue is moot. If we rely on nonrenewable energy, we will eventually run out of fuel, at which point we will be forced to construct solar and wind installations anyway. In the end, we will only have postponed the inevitable for a little while, incurring vast economic and environmental costs in the process. --BRIAN SEEVE