Industrial waste heat is 7 quads in the USA. There is more waste heat from power plants and from cars. Capturing 20% of that waste heat is 1.4 quads every year. 1.4 quads is double all of the wind energy generated in the USA from 2003 to 2006. Further down this article is diagrams and descriptions of the many ways to capture waste heat in cars and trucks (not just thermoelectrics). The positioning of where the temperature differentials are is explained.
This will mean 15% more fuel efficient cars and trucks starting in 2011-2012 and better air conditioners and refridgerators that do not need R134 gas. Applying to our current power plants would be like adding 10-30 nuclear power plants and 150-375 coal plants and 500-1500 natural gas plants that would not use any more fuel because it would be from more efficient use of existing power plants.
This is all very well and good, but it falls far short of where we need to get to in order to mitigate global climate disruption and to live intelligently on “Spaceship Earth”.
If today’s coal plant is around 30% efficient, then adding 15 points to this will bring it all the way up to 45%. That is, we will still be throwing away as “thermal waste” over half of the energy in the coal. Now add in losses in distribution and we start to see the truth of the matter. In a very crude way this is a form of thermodynamic economics. If we want to get to a better place, if we want a good ride on spaceship earth, we need to apply thermodynamic economics system wide to make better informed choices for the possibility of a better future.
Would it, for example, make more sense to pick a system with an end-to-end thermodynamic efficiency factor of 80%? Or pick one of less then 40%? If this were a comparison of rates of returns on money invested in mutual funds, the fund offering only a 40% return would quickly go out of business. So why do we accept such gross in efficiencies in a fundamental building block of our society: our electrical infrastructure?
How high an end-to-end thermodynamic efficiency factor should we demand from our systems and products? How should the thermodynamically informed market “punish” energy wastrels with end to end efficiencies below, say, 80%?
In addition to improving our accounting of how well and how intelligently we use our natural resources, we should look just as hard at reducing our use of energy by at least a factor of 8. We can, for example, build houses today that require no furnaces and can be heated with 1 ton of biomass fuel. This is a 9X reduction in fuel required, which suggests that an 8X reduction overall is not out of the question.
In the end, we must address the fact that we are trying to fill a too big bucket with too many leaks with the wrong stuff. How fast can we reduce the size of the bucket by a factor of 8, eliminate 80% or more of the leaks, and change the “stuff” we use to fill our new and improved bucket?
As for picking a system with at least 2X more thermodynamic advantage, the example I have in mind is Combined Heat and Power and more especially Micrpo-CHP for the 100 million homes in America. We know that it is much more efficient to create the supply at the point of demand. It would, of course, be very advantageous to minimize our use of the grid, reduce as far as possible its inherent thermodynamic waste, and to maximize the productive use of the energy in the fuels we burn. This is the foundation of both what Al Gore calls the “Electranet” and his new goal of fossil fuel free electricity within 10 years. It is also the basis for a new world view that frees us from the shackles of the now dysfunctional Cold War world view.