Perhaps it is a commentary on the standards of contemporary journalism that it was difficult to distinguish between Keller's article (How useful are wind-energy plants? 8/4/06) and a wind developer's marketing brochure. The short answer is not very.

Comparing wind power to conventional hydro power is specious. Hydro power is available when it isn't raining that's what dams are for. Wind energy isn't controllable. More to the point: wind energy's achilles' heel its intermittency limits its capacity value and its impact on emissions. As an intermittent/variable

electricity source, wind energy has not and cannot replace conventional sources (coal, nuclear power and natural gas) of base-load electricity generation. These sources must continue to be maintained and built as our electricity demand grows regardless of the amount of wind energy facilities constructed.

Furthermore, as an intermittent/ variable electricity source, wind energy must be backed up by standby dispatchable generation (usually natural gas) for other than modest amounts of production.

As wind energy penetration grows, the need for backup

and the associated emissions largely offset the purported emissions savings.

In short, modest wind energy production doesn't make much of a difference in reducing emissions, and meaningful levels of production have, at best, a negligible positive impact.

This may help explain why opposition to industrial wind energy is growing so rapidly. Opposition is about more than aesthetics and wildlife, though these are, of course, important issues.

Wind energy's benefits as an energy source and a means of addressing emissions are insignificant and public policies promoting wind energy, however well-intentioned, are simply ill-conceived.

Readers who want the real scoop on wind energy might find Liz Minchin's piece ' Air power will only blow hot and cold as state seeks grid boost' (The Age 8/5/06; http://www.theage.com.au/n ews/national/feathers-flyagain in-battle-of-the-parrots/ 2006/08/04/115419833 1845.html?page3Dfullpage#co ntentSwap2) a worthwhile read. Ms. Minchin has done her homework.

The website of the Industrial Wind Action Group, www.windaction.org, is also a useful resource. Hugh T. Kemper Londonderry, Vermont

--o--

In response to the recent article How useful are wind-energy plants? (August 3, 2006)

I found that the writer kept an even keel on both the pros and cons of the debate. I applaud the local agencies for debating the issue rather than rely on one side or the other. I did find that Ken Nolan, director of resource planning for Burlington Electric Department is out of date with the current thinking in the wind industry. Whoa, let me back up and say that I am as out of step and out of date. As a local municipal staff in an American suburb, I would not have put into writing what he did, highlighting his lack of knowledge. Hopefully within an hour or two he can be up to speed with the latest thinking and hopefully a little less prone to using ten year old theories and thoughts.

I would direct him to the two links, the first are a series of articles that have appeared in some juried magazines lately.

http://www.stanford.ed u/group/efmh/winds/

The second is the email for one of the authors so that he may ask more questions should they arise.

I would encourage the writer of the article to also delve into these studies. While they are a little dry and full of calculations, I believe the reasonable mind will see what the data is saying and what the authors are promoting.

Decentralized wind farms of turbines placed approx. 80 meters or thereabouts can produce reliable, consistent energy.

Cristina L. Archer, PhD

Consulting Assistant Professor

Department of Civil and Environmental Engineering Tel: 415 749 5149 Stanford University Fax: 415 749 4741 Stanford, CA 94305-4020 Email: lozej@stanford.edu

Good luck and thanks for the balanced reporting.

Matt Overeem

via e-mail