Current design of the 7.58 MW we used shuts down at 34 m/s. We tested
this case and the case where the design was altered to allow it to stay
on until the destruction speed of 50 m/s. In both cases, there was a
significant benefit due to the feedback to the central pressure, and the
wind speed never reached the destruction wind speed of the turbine in
either case. This is all described in the paper and supplementary
information.
On 2/28/14 9:29 AM, Christopher Green, Prof. wrote:
I was under the impression that turbines have to shut down ("cutout") as wind
speeds approach gale level. I take it I am mistaken.
Chris Green
-----Original Message-----
From: [email protected] [mailto:[email protected]]
On Behalf Of Mark Z. Jacobson
Sent: Friday, February 28, 2014 11:02 AM
To: Hawkins, Dave; Jim Fleming
Cc: Geoengineering
Subject: Re: [geo] Wind turbines as hurricane tamers?
Dear all, the paper is located at
http://www.stanford.edu/group/efmh/jacobson/Articles/I/WindHurricane/WindHurric.html
The turbines would be installed primarily to generate electric power year around and
would pay for themselves over time doing this. There is a cost analysis in the paper
assuming 1-2 hurricanes striking a given area over 30 years. The cost benefit of the
turbines per kWh averaged over this time is much smaller than the air pollution cost
reduction benefit, which is why the primary purpose is to generate electricity/offset
fossil fuels. Hurricane dampening would be a secondary "free" benefit, unlike
sea walls, which cost $30 billion for one city but don't pay for themselves or reduce
wind speed (only storm surge).
Sincerely,
Mark Jacobson
On 2/28/14 7:07 AM, Hawkins, Dave wrote:
True enough. Suggests that hurricane taming would be at best a secondary
factor in size and location of offshore wind farms. One could do a
probabilistic analysis and see if the hurricane taming potential had noticeable
economic value.
Typed on tiny keyboard. Caveat lector.
On Feb 28, 2014, at 3:56 PM, "Jim Fleming"
<[email protected]<mailto:[email protected]>> wrote:
This analysis assumes you know where "upstream" of a city actually is.
See the attached map of Florida landfalling hurricane
trajectories.<tracks of hurricanes.jpg>
James Fleming
On Sabbatical
STS Program
Colby College
Web:
http://www.colby.edu/profile/jfleming<http://web.colby.edu/jfleming>
Toxic Airs (March 2014)
http://www.upress.pitt.edu/BookDetails.aspx?bookId=36392
On Fri, Feb 28, 2014 at 9:39 AM, Hawkins, Dave
<[email protected]<mailto:[email protected]>> wrote:
Interesting analysis suggesting an action that is both a type of
geo-engineering and emissions mitigation.
Abstract of Nature Climate Change paper
Hurricanes are causing increasing damage to many coastal regions worldwide.
Offshore wind turbines can provide substantial clean electricity year-round,
but can they also mitigate hurricane damage while avoiding damage to
themselves? This study uses an advanced climate–weather computer model that
correctly treats the energy extraction of wind turbines to examine this
question. It finds that large turbine arrays (300+ GW installed capacity) may
diminish peak near-surface hurricane wind speeds by 25–41 m s−1 (56–92 mph) and
storm surge by 6–79%. Benefits occur whether turbine arrays are placed
immediately upstream of a city or along an expanse of coastline. The reduction
in wind speed due to large arrays increases the probability of survival of even
present turbine designs. The net cost of turbine arrays (capital plus operation
cost less cost reduction from electricity generation and from health, climate,
and hurricane damage avoidance) is estimated to be less than today’s fossil
fuel electricity generation net cost in these regions and less than the net
cost of sea walls used solely to avoid storm surge damage.
REFERENCES:
* Mark Z Jacobson, Cristina L Archer, Willett Kempton, Taming hurricanes with
arrays of o ffshore wind turbines, Nature Climate Change, 2014, DOI:
10.1038/NCLIMATE2120<http://dx.doi.org/10.1038/nclimate2120>
Sent from my iPad
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Mark Z. Jacobson
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Director, Atmosphere/Energy Program Phone: 650-723-6836
Stanford University Fax: 650-723-7058
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Mark Z. Jacobson
Professor of Civil and Environmental Engineering
Director, Atmosphere/Energy Program Phone: 650-723-6836
Stanford University Fax: 650-723-7058
Yang & Yamazaki Environ. and Energy Bldg [email protected]
473 Via Ortega, Room 397 Twitter: @mzjacobson
Stanford, CA 94305-4020 www.stanford.edu/group/efmh/jacobson/
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