The optimal and frankly only solution would be the close the coal plant. Arguing that alternative solutions are not "optimal" while continuing burning coal is directly harmful to the environment, green politics and human health.
The first step would be the set a definitive date when the coal plant will get demolished. Once that is done, people can continue to debating what optimal alternative should be constructed but if the date come and there is nothing built then what people get is no power, and the blame then goes to those who refused to build new power plants when they knew ahead that the coal plant is getting demolished.