Solar input in orbit is higher than what is received at ground, but similar order of magnitude. I am not sure there are real world designs for beaming power 100km from space, but you are going to take some amount of loss in transforming the power to a transmissible form, beaming it through the atmosphere, and reassembling it on the ground. Unless you have a pin point death beam, the power is going to be transmitted to a relatively large area, requiring a large amount of land to receive it. Why not just build solar panels there?
Seems far easier to overbuild panels on the ground + batteries.