Among noveltechnologiesforproducingelectricityfromrenewableresources,anewclassofwind
energy convertershasbeenconceivedunderthenameofAirborneWindEnergySystems(AWESs).This
new generationofsystemsemploys flying tetheredwingsoraircraftinordertoreachwindsblowingat
atmosphere layersthatareinaccessiblebytraditionalwindturbines.ResearchonAWESsstartedinthe
mid seventies,witharapidaccelerationinthelastdecade.Anumberofsystemsbasedonradically
different conceptshavebeenanalyzedandtested.Severalprototypeshavebeendevelopedalloverthe
worldandtheresultsfromearlyexperimentsarebecomingavailable.Thispaperprovidesareviewofthe
different technologiesthathavebeenconceivedtoharvesttheenergyofhigh-altitudewinds,specifically
including prototypesdevelopedbyuniversitiesandcompanies.Aclassification ofsuchsystemsis
proposed onthebasisoftheirgenerallayoutandarchitecture.Thefocusissetonthehardware
architectureofsystemsthathavebeendemonstratedandtestedinrealscenarios.Promisingsolutions
that arelikelytobeimplementedintheclosefuturearealsoconsidered.
& 2015TheAuthors.PublishedbyElsevierLtd.ThisisanopenaccessarticleundertheCCBYlicense
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