If the sun isn't shining and there isn't sufficient buffered storage (batteries, etc) then even if the solar panels are a penny each, their kwh costs are infinite until the sun shines again.

If you can cover 95% of the time but still need a natural gas power plant for the last 5%, you haven't saved any money except the cost of the natural gas itself. In the US, it is stupid cheap, so you haven't saved much at all.

This is not about distribution. When sun is not shining, there is no solar energy to distribute. You can build as much solar as you want, but you won’t get any electricity from it during the night. Peak demand, however, is right after sunset, and only slowly peters out until midnight. Where are you going to get energy during that time? If you build enough wind all across the country, so that it is by itself enough to cover the peak demand even during low wind conditions, then it could work — but it’s cost prohibitive, and you wouldn’t then build any solar anyway (if wind was enough to cover peak demand in the evening, it would also be enough to cover demand during the day, no solar necessary).

In practice, until cheap storage is invented, and as long as nuclear energy is eschewed, renewables will be paired up with fossil, and prices will stay up.