Is beaming power through atmosphere even feasible? If it is feasible, why aren't we beaming power at least across sea like Mediterranean for example, where laying cable will be expensive. I always thought space beaming power is just science fiction thing.
I think the atmospheric attenuation problems for a horizontal path are much worse than vertical, not to mention the horizon which would mean many relay stations along a surface path to bend the beam along the curved surface.
However, a bigger problem or question to me is what wavelengths can carry useful amounts of energy and be kept in a narrow beam to have high transmission and conversion efficiency from source to collector. Everything from microwaves up to visible light is going to be quite susceptible to atmospheric moisture. Even microwave and infrared communication links can suffer with rain, clouds, or fog.
If you can get down to radio frequencies, I don't know whether a narrow beam is really possible. I've seen some hints at the development of rasers (coherent, stimluated emission like lasers and masers but down into "radio" frequencies). But I am not a physicist and do not really understand how such an emission would behave. Could a useful amount of energy be targeted on a "small" receiving antenna without leaking out to other accidental recipients...?
Also, for power levels useful to the utility grid, any beam alignment or scattering errors would mean extremely lethal and destructive energy going off-target. Straight down from space, you might delineate a concentric safety exclusion zone around and above a ground station. If beaming horizontally, wouldn't you have to exclude a large wedge of ground and a huge conical section of airspace both before and after the ground site?
From what I can tell, space solar power would be competitive in those places where the alternative is to fly in fuel for generators. For example military forward operating bases, isolated Northern communities, et cetera.
