I'm not sure I recall the exact size of the panels, but they are roughly 30" by about 52". I have 54 of them each rated at 185watts. They connect to 4 Sunnyboy inverters and as you guessed are grid-tied, so the grid is my battery. Battery systems are very expensive and not that reliable as the batteries have to be periodially replaced. I was adviced not to install such a system, and if we had problems of power failures it would be cheaper and better to install an auxilary generator. Check out the NJ state webpage to get the link to their clean energy site - it has great information on solar power systems.