It's going to have to be both. Many homes don't have suitable roofs for supporting enough solar to go totally off the grid. Even those that do often don't have storage systems so still draw from the grid at times.

What I take from this is that we need to have a better way for people to sell excess power back to the grid, or have hybrid systems so they can alternate between their generated power and power from utility companies. Right now utilities buy power from individuals at a significantly reduced rate, which negates most of the value.

Besides that, generating power far away from populations means you're going to have more loss in transmission. Generating it at the site it is needed will reduce the total generating capacity required.