“#Energy Inputs in #Food Crop Production in Developing and Developed Nations,” Pimentel’s #EROEI #paper where he found about four joules returned per joule spent on industrialized #agriculture, #CC-BY, Energies 2009, 2(1), 1-24; https://doi.org/10.3390/en20100001
on 02022-05-21“George Jetson” gets the #EROEI of industrial agriculture badly wrong: he quotes Pimentel as saying the EROEI of industrialized agriculture is about 0.25:1, but what Pimentel actually found was 1:0.25, four joules returned per joule spent. Consequently Jetson’s entire point about “The EROI of global food production” is wrong. #food #energy #agriculture
on 02022-05-21Tom Murphy worrying about economic #collapse from an #energy crunch in 2011, using NREL #EROEI figures about #photovoltaic modules from 2000. From my point of view, a 4-year energy payback time is the same as a 25% limit on the annual economic growth rate: if energy is like super expensive and PV is the only way to get it, then making PV cells will consume nearly all of the energy produced with them, and we can expect the amount of PV power available to double every three years under those circumstances, even if no fossil fuel is available. In 2010 the world produced 31.4 TWh of #solar energy and marketed 148000 TWh of all energy, so about 12 doublings were needed for solar to reach world marketed energy consumption. At three years per doubling, that would be around 2046. The availability of some fossil fuels can only accelerate that trend, under capitalism, anyway. (He makes a good point that a central planner might very easily prefer to devote today’s energy to today's needs instead of investing it to produce returns tomorrow.)
on 02015-08-15