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One comment I think most would agree with: "Well it's about time such a conference was held".
That was fun and we did get noticed, I see, thanks to the professional PR work of Virginia, PJ, Christina, & crew.
Thanks to all who invited me, helped me get the "Sky Serpent" demo up
and running, and everybody who made the conference possible.
My feedback relates to a few questions posed by conference chairperson Christina Archer regarding:
1) Wind shear issues with regard to Superturbine(R) rotor arrays, meaning a variance in windspeed along the line of rotors;
2) What types of wind speed data, and at what altitudes, would most help get this "industry" "off the ground"?;
3) What about medium altitude "jets"?
I agree that wind shear (variance of windspeed from rotor to rotor, at
various points along the shaft) would be an issue with a
Superturbine(R) driveshaft of, say, a mile length.
Stretched between landforms, such as hilltops, mountain peaks, or
across a canyon, the topography would likely affect both the local wind
speed and direction. Rotors closer to the ends of the driveshaft for
example might see lower windspeeds, since they are closer to land, than
rotors suspended out in space mid-shaft, which might be thousands of
feet high, relative to the local land surface.
Suspended between a ground-based or tower-based generator station
(heavy) and an airborne station, whether supported by an aerostat or
powered into position, we'll tend to see lower wind speeds closer to
the ground, and higher windspeeds at altitude.
I thought about these questions on the drive back to Southern
California, which took me over the Tejon Pass ("The Grapevine"),
through the town of Gorman, CA, known for its high winds. The point was
brought home to me that high winds are often associated with high
elevations (the reason for the conference). At about 4000 feet
elevation, going thru these mountain passes, it was real windy.
Wind shear, or difference between wind speeds at a ground station and
the sky above," might be less if one was deploying from a such a high
altitude base station, such as on a mountain or ridge, or at least a
high altitude area. Then your base station is already "in the sky", in
the sense that it is thousands of feet above sea level, at or above the
altitude of the lowest "jets".
What data would be most helpful for us?
Well, I'm thinking that some data on the "wind jets" somewhere between
the hub heights of today's turbines (300 feet) and 1000 feet, up to say
even a mile or 2 above the local land, would be most helpful to at
least get started and up into the air.
I've heard of these "jets" a few times, including "nocturnal jets" and
would like to know more about them. (Jets lower than "the Jetstream") I
think aviation, especially with regard to small planes, and jetliners
when approaching or leaving airports may have some good data as a
starting place, with regard to these "jets".
For "terrain-enabled" high altitude wind energy, I'd like to know more
about the behavior of the winds through mountain passes. It would be
good to try and identify key mountain passes where a Superturbine(R)
driveshaft could be suspended across for high energy capture, with a
high wind energy content and a place for a base station near existing
power lines, for example.
For floating turbines flown from mountaintop or high-altitude sites,
I'd like to try and identify promising sites with high speed jets in
proximity to high-altitude land base-station sites, again with
proximity to power lines if possible.
Just as terrestrial wind energy started out in a few key mountain
passes in California (San Gorgonio, Tehachapi, and Altamont) that had
wind resources many times the average power level at their
"groundhugger" hub heights, I surmise that, for wind power from the
sky, there would be key locations where the winds at say 1000 feet or
even 5000 feet, relative to local terrain, might be far stronger/more
persistent/reliable than average.
These sites might be the same as existing windfarm sites in some cases
(Suspending turbines miles across the San Gorgonio pass?) or might be
new sites not previously considered for wind energy, such as a high
plain site with a persistent jet above it.
I could see extending the existing "class 1-class7" nomenclature for
high altitude sites, using class 8, 9, 10 and up, or starting our own
new classification system. It seems that extending the existing system
drives home the point that the reason we prospect in high places is the
higher resource to be found there, much as though we'd decided to mine
gold from the seafloor canyons near gold-yielding mountain ranges.
As I pointed out at the conference, the way I look at it, the 20th
century was all about drilling down for energy, the 21st century will
be all about drilling up. And just as the oil industry finds preferred
places to drill, we should be looking at finding preferred sites for
high altitude wind energy. Logic says some sites must be better than
others, and a few sites must be exceptional, if we can find them.
Thanks again to everyone who talked me into coming up to a new favorite
area of California (where's Heulle Howswer when you need him?) that I
really like because unlike down here, it is green.
So working from the standpoint of finding a way to "get there from
here" and the fact that high altitude windpower might be most likely to
"grow "from the ground up", and like most organic growth curves, start
out low and gradually get higher and higher, I think even groups hoping
to harness wind 6 miles and higher, might start out running research
prototypes at say a mile above a land-based site already at 5000 feet
elevation, provided there are persistent strong winds above the site at
a reasonable height. Intuition tells me such sites must exist. I say
let's figure out where these promising sites are.
And let's not forget that the competition is already there: people can
already buy fairly reliable wind turbines, and at some point we need to
have an economical product, actually usable by someone, to fill an
actual power production need, whether for battery-charging at a remote
site, or grid-tied operation connected to powerlines.
This solution must at least match the economics of existing turbines to
be attractive to buyers. Remember, a flying wind turbine is still a
wind turbine and people buy them to make power economically. This
suggests "set-it-and-forget-it" type unmanned operation, as even the
average megawatt turbine makes only about $20/hour: not enough to pay
someone to babysit it full time.
Ideally, we should seek to produce electricity cheaper than current
wind turbines, as an improved wind turbine in general is one that is
more economical over the long haul, than existing turbines, with
generation below 4 cents per kWh being the ideal target. If that's not
what we think we can produce eventually, we're likely in the wrong
business and should be making stunt kites or toys for recreation. The
only reason to take any form of wind energy seriously is if it has the
potential to outproduce the status quo for the dollars invested.
OK that's all for now. Nice to meet everyone in person at the conference.
Doug Selsam |
