So, at a time the entire planet is trying to cool off here comes a geezer with a plan to redirect energy that was bypassing the Earth.
Yes I see that the energy providing street lighting could be turned off, but the mirror isn't just illuminating the necessary bits, it's energy is being scattered across the whole city, and not just the streets.
In order that the light be sufficient to turn off street lighting, about 90% of the city that was in darkness will now be absorbing the Sun's energy 24/7.
Ah! but that would mean a lowering in energy required to heat buildings. True, but just as much energy is used to cool them too.
It's a fine idea, but after giving it some thought, it is bonkers mad.