The first question people usually ask after learning that I have solar panels on my roof is whether I bought a battery backup system as well. This makes sense from a basic off grid viewpoint, but not so much in the real world. Most electrical grids have such low levels of renewable generation right now that they can easily act like huge batteries for the small numbers of people who get solar roofs. For grids like this installing individual battery systems is a waste of resources. In this post I’ll try delve into why most solar homes don’t need their own energy storage yet and how this will change in the future.