for solar, a 5km diameter solar farm might hold 10m square meters of panels. at 250w each, 2.5gw solar farm. 4 times a full moon, is 1/100000th the rated capacity (noon at equator) of panels, and so 25kw of power. At 10c/kwh electricity revenue potential, such a farm (exists only in China) could break even offering to rent night light at $2.50/hour.

Batteries charged by solar can deliver profitable electricity at night for far less than 10c/kwh.

If you just want more light somewhere, it would be far cheaper to do from ground systems.