Hmm as to the tank question, very true. A halide would not provide enough power to power one. As to personal use on your homes, thats a different story.
You can actually with enough investment(I did not say they were cheap at all) put on your home depending on your location enough solar panels to power your home and sell power off to the grid and they have to buy it from you. I have noticed here in FL several gas station awnings with their flat roofs completely covered in solar panels for this reason. I also requires your house roof be facing the right direction. Eventually with energy credits they will pay themselves off. This stuff is not cheap however, and you still have night time issues. There are a couple websites out there that tell what regions of the country get what degree of solar energy. Obviously the best place to live if I remember right is the Arizona, NM, SW Texas region, followed by Southern Fl.
Next time you are at a Seafood Resturaunt, ask for grilled Atlantic lionfish. Lets get this badboy on the menu.