Peer review

http://www.arpa.mil/sto/smallunitops/vhesc.html
Gives specifications on how to get a really accurate solar panel. I could not get the rest of the article, but it seems very promising to look further into.

http://repository.up.ac.za/upspace/bitstream/2263/6510/1/Coetzee.pdf
This one caught my eye from the start with a very common question, "Solar Panel Traffic Signals". 629-644pg. Goes in depth with the power usage of all the traffic lights (halogen and LED versions) and the savings. Gives the most effective locations, and how much it would cost to fit those locations with solar panel traffic lights. It also states in the conclusion that solar panels will help the traffic lights in the event of a blackout, which could provide to be quite useful in some cases.

http://ehp.niehs.nih.gov/members/2007/115-4/innovations.html
Even though this is criticized in places where electricity is readily available, this option still proves useful everywhere else. As the article explains, the Vaccines need to be cooled to 3~5 degrees Celsius, without power variation for the best results. Unfortunately, this is good news for places where power is hard to some by, and has a lot of sun.