It is not a new idea, but to generate energy in space with solar arrays may be now possible to SpaceX.
The constraints always were the cost of bring the necessary equipment into space…Thank’s do SpaceX, the cost now it is significantly lower and it is dropping (BFR).
The advantages of generating energy in space are huge…. 55 to 60% of sun energy is lost in ground based solar panel, through the reflection and absorption and of course it would not be needed to use larges areas with solar panels.
The energy would them be beamed back to earth wiressly using microwaves.
I think this technology would not be used for home energy, we have SolarCity for that…but for industrial activities, it would be great. the problem that humanity needs to solve, is energy. With unlimited energy we can do anything, end the hunger, wars and etc.