AWE Lightning                   [Stop animation with Esc key. Start with "refresh page")]

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 decision.

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 Dacron® 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 fluctuating charge on the line as clouds floated by.

CoolIP                       ~Dave Santos            March 19 , 2010          M3228   

Comment and development of this topic will be occurring here.       
All, send notes, drawings, and photographs!

Terms and aspects:   

• static wicks
• static discharger     wiki  
• 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 here.   
• Counterpoise
• lightning rod
• Lightning arrester
• ground, grounding
• capacitance
• inductance
• voltage
• current
• 
•  

Related links:

• Links
  • http://www.physlink.com/education/askexperts/ae568.cfm  "static wick"
  • Lightning (folder of links in forum)
  • Vaisala Thunderstorm Total Lightning Sensor LS8000
  • Tesla coil    wiki 
  • Atmospheric electrical generator   [consider kite or kytoon in applicant's teaching]
  • Expert comment invited: Is there a place in AWECS for: Click for full instruction.
     
  • Energy harvesting
    
     
• Images
• Files
• Forum posts
  • v
  • v
  • v
  • v
  •  

Commentary is welcome:

• The whole realm of atmospheric electricity is larger than the lightning-event sector.     ~JoeF
• 
  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 ???   
  • http://www.vias.org/radioanteng/rae_01_12_04.html
  • Counterpoise (ground system)
• 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 AWE
  operations we propose. KiteLab Ilwaco has twice encountered a less dangerous
  electric hail with St. Elmo's fire, resulting in one breakaway.
  
  Robert is right that even a plastic non-conducting line can become conducting,
  especially by salt vapor and wet. We do not have data to establish what level of
  risk a plastic line in good condition has, but its seemingly far less than the
  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 build-up.
  9. Keep away from surface equipment during lightning hazard.
  10. In salty air, perform periodic fresh-water rinsing of kites and lines.
  
  By following these methods the lightning risk becomes very low.          ~DaveS
   
• 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 damaged.

  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                 http://flygenkite.com  
   

• 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
  predict strikes.
  http://www.blitzortung.org/Webpages/index.php
  http://ukweatherworld.co.uk/forum/category-view.asp
  http://www.estofex.org/
  http://www.lightningwizard.com
  etc.           ~ RobertC
   
• July 18, 2011:     Continuing the theme of danger, a kite can also accumulate
  static electricity and by landing can be quit strong
  discharge.     ~AlexM    
   
• .