Let There be Light

I know its corny but I find myself going in and out of the downstairs bathroom. we installed a sensor that automatically turns the lights on and then turns them off 15 seconds after leaving the room. If you have kids, then these are essential to saving energy. They cost 15 dollars and are installed in about 30 minutes (if you are good at electronics a lot faster). Anyway, we figure there are lots of rooms and closets where the automatic lights can help. we'll need every bit of help as we'll need to cut our family's energy use by 25% in order to have zero electric bills after our solar panels are installed in about two weeks!