Professor Harold Sabbagh (my favorite teacher at Purdue in the 50’s (a couple years before the first LASER was demonstrated) proposed a wireless energy transmission scheme based on using solid-state diodes to capture the energy of a focused beam of RF energy. The primary obstacles: material costs, system inefficiencies – particularly pathway obstructions such as dust, water vapor, birds, etc., limited component lifetimes, and unpredictable regulatory obstacles.

Since you’re already considering at least one LTA application, you might want to add http://www.naval-airships.org to your rolodex.

Aerostats, airships, and balloons provide two unique advantages compared to the Space elevator and other aircraft: They provide large targets capable of supporting powerful receiver arrays; They can productively employ (and rapidly dissipate) the heat produced at the receiver interface.

UPSHIP,

Albert H. Robbins
CDR USNR(Retired)
Indianapolis, IN 46226

p.s. If the pointing mechanism becomes sufficiently agile you might be able to discourage large birds from frequenting airports.