Not all signs face one direction. Some are sideways along a roadway to show information to people traveling in either direction. There are also ones that show a welcome on the entrance side and a thank you on the exit side. No matter what your sign says, lighting it at night will provide the information to the passersby’s no matter when they go by.
You can mount a single solar array to power a fixture on both sides of the sign. This design doubles the amount of solar required; however, it will provide the best option for these types of signs. Having a solar for each fixture doubles the maintenance and overall cost of the system.
You can even do the same with an internally illuminated sign that shines the light out through both sides evenly. Either with LEDs or Fluorescent lamps, a single solar power system can provide the power for the light fixtures to provide lighting for both sides of a sign.
The solar power assembly can be located beside the sign, attach to the top of the sign, or even be placed up to 100 feet away so as to allow direct sunlight all day. The solar power system should be sized to provide a minimum of five days autonomy to allow for times of inclement weather and never allow your sign to be left in the dark. So next time you need that double sided sign lit up, consider using solar power to provide the needed energy and a green solution.