There is a solar water heater system. The system has the following: a sealed storage tank, a reflective surface, and a vacuum tube. The sealed storage tank is adapted to retain water. The tank has situated at an outer surface thereof a thermal insulating layer of a closed-cell polyurethane or polyisocyanurate foam having a blowing agent therein having about 60 wt % or more of 1,1,1,3,3-pentafluoropropane therein. The reflective surface is capable of reflecting sunlight. The vacuum tube extends along the reflecting surface between the reflecting surface and the sun. The vacuum tube is in communication with the tank. There is also an outdoor insulative storage tank system.