Why put this at L1? Rather have a Starlink-style massive fleet of low orbit satellites. Picture something like a mylar-sheet with a tensioned outer rim that c

Why put this at L1? Rather have a Starlink-style massive fleet of low orbit satellites. Picture something like a mylar-sheet with a tensioned outer rim that can be folded small and then pop open after release and placement in orbit. For bonus marks make it controllable by interacting with the earth's magnetic field - a current in the outer rim could be used to align it relative to the earth's magnetic field. If the surface is mirrored and they are controllable you could use it to reflect sunlight onto areas to heat them - so you could heat bodies of water to increase vaporisation and you might be able to create air movement by setting up temperature gradients. You basically want an artificial ring - a set objects in orbits that can dim the sun by up to about 2% in the brightest part of the path of light from the sun to the earth.