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A simple "lightning detector" is subject to a prankster with a spark gap
or a non-threatening super strike many miles away downwind, so we need the
fancier lightning-mapping detection that comes with aviation radar. The
rain returns are constantly refreshed but the radar keeps a memory going
of the strikes. You would need to process this data for a smart retract
Aircraft use static wicks to keep charge from building too high & there is
no reason we can't put little wicks on lines & kites. We could also
actively cancel charge so that the semiconductive line remains invisible
to the lightning. Similarly the kitefield surface charge could be actively
canceled and lightning encouraged to strike elsewhere, but active
cancellation is an uncertain trade-off, probably favored in high lightning
zones like Florida.
Large meshed arrays of multi-tethered kite elements would tolerate
considerable local lightning damage and remain flying. Low mass kites
disabled by lightning are far less dangerous in a crash than high mass
kite crashes. Whatever the mishap mode, replacement cost is far lower for
a cheap rag wing than a fancy composite structure wing. During lightning
risk, we might also launch lightning-rod kites on piano-wire to shield
nearby arrays of critical kite systems, but this is pretty awkward.
I have experienced electric hail twice while kite flying, experiencing
sparking, and once even bathed in
St. Elmo's fire. The second time a
DacronŽ tether long exposed to salt vapor burned through, but would
probably have held if it had been rinsed. An electroscopic charge detector
on the kite and line will detect precursor charges before lightning
strikes, but also less scary "electric hail" and ionized dust. I
made a simple tinfoil-vanes-in-a-jar electroscope and found it sensitive to
charge on the line as clouds floated by.
~Dave Santos March
Comment and development of this topic will be occurring here.
All, send notes, drawings, and photographs!
Terms and aspects:
- static wicks
- static discharger
- retract decision Decision to bring in
or bring down an energy kite system is a retract decision.
- St. Elmo's fire (also St. Elmo's light)
- active lightning cancellation
- Disambiguation on "electric hail". Consider:
Volta's "electric hail" and
- lightning rod
- ground, grounding
- Forum posts
Commentary is welcome:
- The whole realm of atmospheric electricity is
larger than the lightning-event sector.
Click text image for full instruction in a patent application of 2009.
- Mail or chain mail is a type of
armour consisting of
small metal rings linked together in a pattern to form a mesh. The word
chainmail is of relatively recent coinage, having been in use
only since the 18th century; prior to this it was referred to simply as
mail. AWECS ground-station worker clothes?
- The circa 1921
Hermann Plauson direction might be revisited with metallic-threaded
textile parafoil kites or kytoons.
- Counterpoise ???
- Aluminized textile by Festo
- July 18, 2011: There has always been a lot of discussion
of lightning hazard on this forum, but
the review is worthwhile.
Yes, lightning will be a common hazard in the exposed round-the-clock
operations we propose. KiteLab Ilwaco has twice encountered a less
electric hail with St. Elmo's fire, resulting in one breakaway.
Robert is right that even a plastic non-conducting line can become
especially by salt vapor and wet. We do not have data to establish what
risk a plastic line in good condition has, but its seemingly far less
well documented wire-line hazard.
Here is a current KiteLab Lightning Hazard Mitigation Protocol-
1. Avoid conducting line designs.
2. Use redundant lines to reduce runaway risk.
3. Bring airborne elements down well ahead of a storm (add kill-lines).
4. Use every forecasting resource.
5. Be vigilant of "pop-up" storms. Any nearby lightning is a red alert.
6. Ground fixed surface equipment to code standards.
7. Bleed off static charge aloft with TE "whiskers".
8. Use an electroscope (DIY metal foil or FET) to monitor charge
9. Keep away from surface equipment during lightning hazard.
10. In salty air, perform periodic fresh-water rinsing of kites and
By following these methods the lightning risk becomes very low.
- July 13, 2011:
A technician of cable railway indicated to me that often during
thunderstorms the electronic elements _ installed in stations, absorbing
the lightning via wire cables assuring the travel of cabins _ are
So it is possible a similar problem exists for AWECS of type
flygen in regard to reliability. In my opinion, for this but also for
other reasons (losses in the cable, weight aloft) AWECS of type flygen
are good at limited altitudes where it is possible to retrieval quickly
the kite. Otherwise new technologies (nanotube with light non conductive
protection) will be needed. ~PierreB
- July 18, 2011 .....
Having lived in an area with some of highest lightning strike densities
in the world I have learnt to have great respect for its power. I have
been within 200m of strikes and even at that distance it is an
experience you never forget. Even non conducting tethers will collect
dirt and conduct better than air. Tethers of any type will attract
lightning and even a mild strike will break them. Health and safety
legislation is increasingly used by control freaks to massage their egos
so any lightning accidents involving AWE could be bad news for our
cause. There is therefore no option but to be alert for the build-up of
static and to land the kites before the activity gets to dangerous
levels. Fortunately there are experts with websites who can help us
- July 18, 2011: Continuing the theme of
danger, a kite can also accumulate
static electricity and by landing can be quit strong