Wind and solar are demand independent generators, you need a lot of adapting feedback (like load-based pricing) to integrate that succesfully into an electricity system that is demand driven, and even then it is still a source of distortion, a challenge to the reliability.

Batteries are really lacking, lagging in capacity, compared to size and price to be a viable way forward for this problem. We need leaps forward in battery tech, but only seem to be getting small steps.