Most grid tie systems have no storage capability either, its a cost save, batteries and charge controllers and such are expensive.
Power usually goes out in a storm when there is a lack of sun.
I was looking at solar for a cabin on the farm and was researching and on differnet forums and some forums are very pro grid tie and anti sotrage, better to share the excess produced energy with others via the grid and not have bateries which will eventually need disposed/recycled and use resources to manufactur. They couldn't get past the fact that I wanted storage based rather then having to cut miles of trees down to run electric lines to connect to a rural grid which is down more than up in the winter. I don't hang out on that forum much anymore.