Reality check:
Cap & trade isn't about fuel supply at all, let alone a limitation on it.
We're not going to stop burning fossil fuels anytime in the near future. Maybe not the in the forseeable future at all. It's not just power generation. It's cars. Millions of them on the road this second, just in the US. People still heat their homes & cook with it.
This isn't France. The government doesn't supply our utilities. Personally, I like the French system, but it can't work with a free market grid, & Americans are still hung up in cold war rhetoric to the point that a socialized power grid isn't going to happen.
When you burn fossil fuels, there's going to be emmissions. The trick is to recapture those emmissions, reprocess them, & resell the products created from that process. There's already working prototypes that separate chemical compounds & make organic agricultural fertilizers. The current scrubbers recapture sulpheric acid & the flyash that carries it. Both are resold for a multitude of purposes, & flyash has been a boon to the cement industry. The possibilities are practically endless. It's just a matter of dragging corporate America, kicking & screaming if necessary, into the modern world.
Will speculators be getting involved in trading the caps? Of course they will. This is America. Welcome to the world of capitalism.