I wasn't particularly interested in energy. But no-one at Uni told me that in the time it took the global economy to double, world energy use quadrupled*. That would have been relevant. And I like to eat, but no-one told me that it takes 10 units of energy on the farm to produce every unit of energy of food**. I think I would have taken notice of energy then.
Now I think that the growth in the global economy was from the bonanza of accessing fossil fuels, especially petroleum. It's highly portable and super concentrated, and still very cheap, for now...
I've learnt that net energy is everything. Net energy is: how much energy does it take to find and access or produce the energy? Alternatively, net energy is the energy that remains after the energy production costs have been deducted.
Unsurprisingly, we took the cheap and easy oil first. When first discovered in US in the 1930s the estimated energy return of oil finds was in excess of 100:1. That is, the energy returned from that early drilling was 100 times the energy that it took to build the wells etc. What a bonanza! Now the global average is about 20:1, with new oil fields considerably lower.
The net energy concept also applies to electricity generation. Beyond Zero Emissions (BZE) are doing the country a huge favour by co-ordinating volunteers to do the numbers on moving to 100% renewable energy sources. (What are the CSIRO paid to do?)
I went to a recent BZE presentation held in Newport and hosted by the Greens. I feel confident someone at BZE knows the net energy return of their recommended wind and solar thermal technologies. The presenter had done the BZE training and done 100 or so presentations before. But he didn't know the answer to my question about their net energy return. I'm not criticising him. I think it shows our society believes that technology will come to the rescue of our energy problem.
When our community achieves energy literacy (archived copy) net energy will be at the forefront of BZE's presentation.
* I remember reading this at Chris Martenson's the crash course, but can't find it easily again, sorry
** Seems to originate in Bill Mollison's work.
Written by Kate Leslie (links updated 22 August 2014)