Sorry I was mixing Neon and Helium there. I meant Helium of course.
I think this also brings up an interesting subject; as some of these buoyant gases are also climate gases (methane 28-36x global warming potential compared to CO2 according to ChatGPT, hydrogen and ammonia small potential). So if Methane was selected as a gas, the leaks worldwide would in sum over time contribute to significant global warming. So a renewable energy world would probably not be built predominantly on methane as an energy carrier.
Ammonia still seems borderline usable though it seems issues with smell, toxidity, corrosiveness and flammability make it a non starter for many applications.
I would like, though to compare flammability of ammonia vs hydrogen. Hydrogen is flammable in concentrations 4% to 75% mixed with air, but the same number for ammonia is 15% to 28%, making it easier to deal with. For example, if a cylinder was filled with “100%” ammonia gas, you would have to mix a significant amount of air and also have an ignition, before the cylinder exploded. Such a leak would probably be detectable through pressure drops if the internal pressure was higher than atmospheric pressure.
So while Helium is both cheaper and better in almost all respects, if it can’t be used, the options seem difficult to implement. And if lighter than air AWE is to give a significant power contribution to the earth, vast amounts would be used.
Lets estimate how much gas is necessary. Lets use the Wind Fischer MAG100 as an example. It is 160 m3 volume and lets assume it produces 100 kW [I did not find any stated power on the web page]. In 2023, 1 terrawatt of wind energy was installed over the world. Lets assume we double that by installing MAG100s. That would require 1.630.000.000 m3 of Helium gas just for the initial fill. This represents (according to ChatGPT) 5% or the world’s Helium gas reserves…