Solar and wind are intermittent
Solar and wind are as noncompetitive as they are intermittent.
Solar and wind alone can’t quickly replace all coal power plants, due to their main downside: intermittency, i.e., when the sun doesn’t shine or the wind doesn’t blow.
Compensating for such downtimes can only be achieved with:
-batteries and other solutions to store electricity such as pumped hydro-storage or hydrogen production;
-supergrid expanding the distribution of renewable energy from the US windy Midwest to night-time in the Northeast.