Coal, gas and oil fired generators have inbuilt redundancy, and not being stuck high up in the sky on a tower, are more accessible for ongoing routine maintenance. Now if all renewables had reliable backups, it would not be such a problem, but they don't, and if it was mandated that they did, they would be an even less affordable source of electricity than what they are currently.
This image illustrates just how little renewables contribute despite the hugh cost that has been imposed on the consumers, so if doesn't take much imagination to work what the cost would be to have renewables responsible for producing a significant amount of electricity, and remember, this image is of a period of low demand.
Whilst there has always been technical solutions invented to solve most problems, only those that are economically affordable survive. On that basis coal is going to be around well into the foreseeable future. The 700 new coal fired units currently under construction globally, and the thousand odd that are well advanced in planning are going to be using coal to produce cheap reliable electricity over the next few decades for those governments and populations that are not being blinded by the religion of climate change, to the reality of life. Demand, and the price of coal, is currently undergoing a strong recovery now that such realities are being increasingly recognised.
