A number of people have suggested wind energy as a means of meeting our energy needs, so let me offer a cautionary note. Wind turbines are starting to show up on ridge tops in Pennsylvania. Besides the problem that this causes for migrating birds and bats, there are some other things to consider. The cost of purchasing and erecting a single 2 MW turbine is over $2 million, and would be prohibitively expensive if not for federal wind energy tax credits. Even in the best locations in Pennsylvania (ridge tops), these turbines only operate at an average of 30% efficiency. In theory, even at 30% efficiency, a single turbine should provide enough power for 600 homes. However, most of that electricity is produced during the spring and fall months, and power demand is highest in the summer. In theory, it would take over 5000 turbines to provide the energy equivalent of one coal fired power plant. However, to meet peak summer demand, it would take over 9000 turbines. Turbines are usually placed a minimum of 200 meters apart (8 per mile). That translates into over 1000 miles of ridge top to replace one power plant. Even if we ignore the ecological costs, there simply aren't enough ridge tops for wind to meet more than a small percentage of our electricity demands. The equation gets better in places like North Dakota that have more consistent winds, but then you face issues of energy loss during transmission to areas where electricity is needed (not to mention all the immense power lines needed). So while wind may play a role in meeting our energy demands in the future, it will not "solve" our energy problems. I haven't done the math, but I wonder how much energy could be saved if the same $2 million spent on one turbine were used replace a bunch of standard incandescent light bulbs with energy-efficient compact fluorescent light bulbs.
Tim. ------------------------------------------- Tim Maret Department of Biology Shippensburg University Shippensburg, PA 17257 717/477-1170 [EMAIL PROTECTED] -----Original Message----- From: Ecological Society of America: grants, jobs, news [mailto:[EMAIL PROTECTED] On Behalf Of David Bryant Sent: Friday, February 02, 2007 1:43 PM To: ECOLOG-L@LISTSERV.UMD.EDU Subject: Re: [ECOLOG-L] Ethanol (in)efficiency One observation keeps me skeptical of ethanol: photosynthesis is only 1% efficient at converting sunlight to biomass. So regardless of how many resources are used to produce biomass of any kind for energy production, the same area covered with solar PV cells is 10-15 times more efficient. Now if we can just resurrect the electric car and convince ADM to grow polysilicon. ;-) It has been hypothesized that the surface area of Arizona covered with PV could supply the US with all it's electricity needs. Along similar lines: wind power in the Dakotas could do likewise. While I understand the limitations, logistic and political issues of these proposals the point is that A) these technologies are practical and available, not as low percentage contributors, but replacements for fossil fuels. One additional advantage of wind over bio-fuels is that wind is a simultaneous adjunct to agriculture, producing both energetic and economic benefits to farmers, and the general population. With these power sources in place other renewable bio-fuels could replace fossils for transportation. And lets now forget the most immediate energy source: conservation! David David Bryant [EMAIL PROTECTED] 978-697-6123 On Jan 29, 2007, at 7:00 AM, Maiken Winter wrote: > Hi all, > > We just had a discussion on ethanol on the Tompkins Sustainability > listserv, and I would like to share one of the most interesting > inputs from > an employee of an independent energy firm in our area: > > At Cornell, a study has shown the inefficiency of ethanol; please see: > > <http://www.news.cornell.edu/stories/July05/ > ethanol.toocostly.ssl.html>http://www.news.cornell.edu/stories/ > July05/ethanol.toocostly.ssl.html > > "It seems as if the final word on energy efficiency is still out. > Pimental, who is widely and correctly quoted, is viewed as an > extremist. > ( He may still be right), Most research indicates a tiny bit of > positive > energy produced with corn to ethanol9 10-20%, and a little better for > Biodiesel from soybeans. > > Some interesting articles are listed below: > > Drunk on Ethanol- Audubon Society: > <http://magazine.audubon.org/incite/incite0408.html>http:// > magazine.audubon.org/incite/incite0408.html > "But the reformulated-gasoline program has turned out to be a colossal > failure, and the ethanol industry has transmogrified into a > sacrosanct, > pork-swilling behemoth that gets bigger and hungrier with each > feeding. > Ethanol dirties the air more than it cleans it. Its production > requires > vast plantings of corn, which wipe out fish and wildlife by destroying > habitat and polluting air, soil, and water. Of all crops grown in the > United States, corn demands the most massive fixes of herbicides, > insecticides, and chemical fertilizers, while creating the most soil > erosion." > > "Does it take more energy to make ethanol than is contained in > ethanol? > That question continues to haunt the ethanol industry even after 27 > years of expanding production. Over the years more than 20 scientific > studies have examined the question. This document contains links > to the > major studies of the subject completed during the last decade." > <http://www.newrules.org/agri/netenergy.html>http:// > www.newrules.org/agri/netenergy.html > > > Here is a good article from renewable energy access, by LesterBrown of > Worldwatch. > <http://www.renewableenergyaccess.com/rea/news/reinsider/ > story;jsessionid>http://www.renewableenergyaccess.com/rea/news/ > reinsider/story;jsessionid > =DDB1143EA1BF449D5EFC92ADE6723FDE?id=47092 > > "The U.S. Department of Agriculture (USDA) projects that distilleries > will require only 60 million tons of corn from the 2008 harvest. But > here at the Earth Policy Institute (EPI), we estimate that > distilleries > will need 139 million tons -- more than twice as much. If the EPI > estimate is at all close to the mark, the emerging competition between > cars and people for grain will likely drive world grain prices to > levels > never seen before. The key questions are: How high will grain prices > rise? When will the crunch come? And what will be the worldwide effect > of rising food prices? > "From an agricultural vantage point, the automotive demand for fuel is > insatiable. The grain it takes to fill a 25-gallon tank with ethanol > just once will feed one person for a whole year. Converting the entire > U.S. grain harvest to ethanol would satisfy only 16 percent of U.S. > auto > fuel needs. > > The competition for grain between the world's 800 million motorists > who > want to maintain their mobility and its 2 billion poorest people > who are > simply trying to survive is emerging as an epic issue. Soaring food > prices could lead to urban food riots in scores of lower-income > countries that rely on grain imports, such as Indonesia, Egypt, > Algeria, > Nigeria, and Mexico." > > Today's Ithaca Journal has a report on "Mexican President tries to > contain tortilla prices" due to a surge in corn prices driven by > the US > ethanol industry. Seems like the riots are about to start... > > And Iowa may have to import corn next year, from who knows where? > <http://www.farmandranchguide.com/articles/2007/01/05/ag_news/ > letters_and>http://www.farmandranchguide.com/articles/2007/01/05/ > ag_news/letters_and > _editorial/letter02.txt > > According to IATP numbers, the biofuel boom - if fulfilled - will > require Iowa to import 200 million bu. of corn, rather than export 670 > million bu. as it did in 2005/06. Nebraska would need even more, 421 > million bu., to fill its ethanol-made hole." > > Now, here is just one sentence from myself: > If - as it seems - ethanol is a hoax, shouldn't we speak up, also > for the > sake of the remaining prairies that might be at stake? > Maiken > > Maiken Winter > Cornell Laboratory of Orntihology > Ithaca, NY 14850 David Bryant [EMAIL PROTECTED] 978-697-6123
