by gego » Sat 16 Dec 2006, 04:45:48
Earlier I posted a little table showing the percentages of gross production that would be left after paying the cost of production in energy terms.
I have been thinking about this and wanted to highlight the idea because I think that the dry presentation of the table may not have the impact that it should.
If you notice going from a 100:1 to a 50:1 EROEI (a halving) only changed the % we had available from 99% to 98%, not much of a loss in net production available. Assuming 1,000,000 barrels of production instead of having 990,000 left, we would have had 980,000 left or only experienced a loss of 10,000 from this halving. Note that this change in EROEI really happened from 1930 to 1950 according to the original post in this thread.
It is a little unclear where we are today as far as the EROEI for oil, but let us assume that we are near 6.25:1 for the year 2010. (If anything we are lower than that.) In going from 12.5:1 to 6.25:1 from 1990 to 2010 the loss on 1,000,000 barrels of production would have been 80,000 barrels (920,000-840,000). The EROEI ratio halved, just as it did going from 100:1 to 50:1, but the loss of available production because of increased energy cost was 80,000 barrels instead of 10,000 barrels.
If the EROEI falls by 1/2 again from 2010 to 2030, going from 6.25:1 to 3.125:1 the loss in on 1,000,000 barrels of gross production would be 160,000 barrels (840,000-680,000). At a ratio of 3.125:1, the available production out of 1,000,000 barrels is only 680,000 after subtracting the barrels that must be used to produce that 1,000,000 barrels.
Another halving from 3.125:1 to 1.5625:1 gives an astounding loss of 320,000 barrels out of 1,000,000 and at 1.5625:1 all that is available out of 1,000,000 barrels for human use is 360,000 barrels; remember that at 100:1 back in 1930, 990,000 barrels were left.
I am sorry to labor into all these numbers, but I suspect that if you wade through this, you will be as astounded as I am at what a dramatic effect on net energy available these low EROEI ratios have. I doubt seriously that when people hear that the era of cheap oil is gone that they really have a clue what that means.
And again, this escalation of cost will continue irrespective of peak oil; all the cheap oil has been found. Add the loss in gross production after we hit peak, and the "perfect storm" does not nearly convey the true picture.