Lighting up the streets with solar power
The Canadian company, Pure-Tek Earth, has designed a solar powered LED street light where the switch, converter, controller, the wiring and the solar battery fit into a metal box that is mounted on the individual street light pole.
Pure-Tek Earth describes on their website how the solution can save thousands of dollars in electrical costs and save the world from one ton of CO2 emission per light, per year.
There is no mentioning of centralized control of the street lights, so it is unclear whether this is an option. Also, the ROI is not described, perhaps because it is unreasonably long? Equipping every single street light with both solar batteries, controllers, switches, etc. must be rather costly.