Solar Lights? Hmm, uh, well, leg's see. It was the Soviet Space Station which made the best use of Solar power, keeping the entire space station going on batteries. Solarpower can be freely generated & temporarily stored, for use a bit later. I have seen a solar battery used by a Mennonite man who was quite progressive! Oh yeah, I have several of them in my front yard along my driveway. They light the area afater dark till about 3-4 in the morning. The elec company wants $78 from me for the elec I used inside the house for last month. If I could, I would use all the solar power I could, & just use the elec backup when there is not enough light to recharge the battery cells. Not to mention the extreme dangers all day every day, with many of the nuke & fossil fuel power plants in service today. Solar is an unending supply--except when it is too cloudy, & then it usually is sunny again in a couple of days in my part of the country. I haven't used a battery powered little calculator in 20 years!