You may have missed it. It takes a lot of energy to make electricity.
A nifty NY Times metric early this summer shows that about two-thirds of the energy released in the process of generating electricity is lost - mostly in the form of heat. It creates steam to spin turbines. Then, mostly, it is lost through smokestacks. Distribution line losses equal about 3 percent of the energy coursing down the highway.
So the residential consumer ends up with the equivalent of 4.6 quadrillion British thermal units of energy. The commercial sector gets 4.4 quadtrillion Btu. And industry takes 3.4 quadrillion Btu.
That leaves 28 quadrilliong Btu lost. Squandered. Gone. There is promise that boosting the efficiency of the power generation process is doable. The objective is to move the conversion efficiency needle from 36 percent to closer to 50 percent.
It may not be as nifty as planting solar panels in the Sahara, or wind turbines off the Nordic coast. But tinkering with a steam turbine configuration, the design parameters of a power line, the greater use of combined-cycle like technology that makes extra efforts to extract heat from exhaust gases - can be hugely significant.
Now who exactly are the political and industry leaders who are going to put some research dollars into such hard but imprortant work? Anyone?
It has been acknowledged for a number of years, mostly by the engineering community at large, that approximately 50% of the thermal energy present in the fuel is wasted, meaning that it is not converted to electricity. This loss is shared between the stack (10%) and the cooling system (40%), and this is where Martin inadvertently erred. This fact proves why combined heat and power (CHP) systems are so much more efficient; after the electric power has been generated the heat, that otherwise would have been wasted, is used in some drying or other industrial process, or to heat one or more buildings.
Martin has hit the nail right on the head! This is an often overlooked aspect of thermal energy conversion, as we generally practice it in this day and age, and one which deserves much more attention. I intend expanding on this theme in the future posts I refer to above, just as soon as time permits.
Also remember renewable energy such as wind, solar and geo-termal don't have waste heat, they don't use water to make energy and the fuel is free from the Sun just when we need and use it most. Hydro fills in the base loads.
Renewables also don't make pollution like coal, NG and Nuclear.
My first comment focused entirely on the heat released into the atmosphere by thermo electric power stations via their cooling systems, whether by cooling towers or once-through cooling, Coal-fired, gas-fired, combined cycle, nuclear, and wood chip fired, all come under this heading. By capturing this wasted heat and converting it to electric power we would gain an additional 241,271 MW by the year 2030 (extracted from 2006 EIA figures). And, since no fuel would be consumed, this would significantly offset greenhouse gases (GHGs) while creating a substantial positive cash flow for the power generators involved. True zero-emissions power generation.
To quote the last paragraph of Martin Rosenberg's blog ("How Do You Spell E F F I C I E N C Y ???", August 29, 2008), "Now who exactly are the political and industry leaders who are going to put some research dollars into such hard but important work? Anyone?" I see that as a challenge. Let those with the foresight, and the courage to take some risk, and above all, those who have faith in American engineering, please step forward and let us at least make a start on all that has to be done. As they say, "Time is of the essence!".