Being able to see when the sun is down and the power is out is usually not a big deal. Emergency lighting in most buildings and the flashlight feature on millions of smart phones around the globe is enough for the general populace.
The main problem with that is if the loss of power lasts for more than a couple days, you are stuck in the dark and have no back up. Flashlights and even candles have a finite amount of time before their fuel has been consumed and you are left in the dark again.
With a little ingenuity, and a handy step by step guide, you can turn those little solar yard lights you see in yards all over in suburbia into an emergency light source. With a few simply modifications, you can install a on/off switch that will allow you to not only harness the power of the sun and use it normally but also save it for when you need it!