Sunday, October 28, 2012

Rejected Energy ~ A function of process inefficiencies (LLNL)

Lawrence Livermore National Laboratory released their latest report on US Energy usage.  Interestingly, the total is notably less that the 2008 figure (99 vs. 97 Quadrillion BTUs).  Both are presented below.  According to my widget on this blog (originated HERE), the US is on track to an even more significant reduction in energy usage > according to this calculation > 75.6 @ Day 302 of 366 > translates into only 91.6 Quadrillion BTUs for year end.  It may be an expression of somewhat different measures also.

Regardless, my curiosity is keenly engaged when I see that the rejected energy EXCEEDS the energy services - and not by an insignificant amount.  This means that energy released is greater than that we receive from our efforts.  The definition' taken from LLNL's report:
" ... is the division between “useful” and “rejected” energy based on estimates of conversion efficiencies in the various end-use sectors. “Rejected energy” consists primarily of heat losses. Conversion and plant losses at electric utility generation stations that burn fossil fuels are a matter of record, but inputs to total transmitted electricity such as nuclear and geothermal power, are associated with estimated efficiencies of the conversion process to electricity. These estimates vary from 90% in the case of hydroelectric power to 18% for geothermal energy."
Below are the diagrams for 2008 and 2011.  In each example more than 40 Quadrillion BTU's are received in energy services > while more than 50 Quadrillion BTUs are lost, released and ... essentially wasted.  If our capital systems worked that efficiently, we'd already be broke ~ wait - maybe there's something to that thought?!

Regardless, there has to be a better way ~ particularly in light of the significant challenges we see with modern society and the likelihood of continued growth by both developed and undeveloped nations.

No comments: