It's not quite that simple!
If you stop expecting the lights to come on when you hit the switch,
of stop expecting your refrigerator to stay cold, or your HVAC to work, maybe, but until then,
we need a replacement ready, before we "stop using coal"!
I acknowledge that my earlier explication was too laconically presented. I was alluding to the principles of "goal setting 101."
Of all the steps in the process, be they steps that provide alternative energy sources or any other, the key step that hasn't yet been taken is the first one: Decide to stop using coal. Unless and until that step is taken, whether any one or any several individuals/organizations, to say nothing of a nation as a whole, replaces coal is little more than serendipity.
I know step one seems obvious, at least it does to me, given that replacing coal on the scale I believe you have in mind is much like going to the Moon. Curiously, while "step one" is among the least complicated and easiest to perform step in any process, certainly it is in the process of replacing coal, it's the one that far too many people overlook. One result of that omission is that the nature, extent and alacrity of outcome achievement suffers. To wit, if Kennedy hadn't made it a national goal
and priority, there's no telling whether we'd have done.
AFAIK, however, step one in the process of achieving the outcome you've identified -- replacing coal -- has yet to be made formally, which is why I mentioned it. Yes, of course, there are subsequent steps after step one -- things like identify alternative energy sources, design, build, test and deploy alternative energy solutions, etc. -- but the fact remains that the single most important step in achieving any given outcome is to define doing so as an irrevocable goal, and in the U.S., at least, no such goal has, by leaders who can make it happen, been defined, even though some folks, maybe even leaders, have done so in an unconcerted way.
