Thomas Casten, Chairman of Recycled Energy Development LLC has published an article on Energy Pulse titled Mitigating Climate Change: Asking the Right Question. He provides a good analysis of the benefits of smaller power plants that are able to use by-product heat recovery systems.
He then compares the climate changing emissions of these systems to large, central station power plants that must consider that heat as a true waste product that must be removed by smokestacks and cooling systems.
It is a good article with a useful discussion building on it. It is always useful to get such information from people who have done the numbers about energy systems carefully enough to confidently go out and use them as the basis for starting and operating a business. Go check it out.