Net Energy & Embodied Energy: Subverting the Industrial Paradigm

Cliff Harper, Liberated Terrace (1970s)

[part 4 of my introduction to Ecology 101]


Net energy is the energy provided by any activity or technology after the total energy needed to produce and maintain the activity or technology itself has been subtracted from the energy provided. Also known as the EROEI rate (Energy Return on Energy Invested). Net energy or EROEI analysis thus also looks at the embodied energy (or hidden energy subsidies) within the activity or technology itself to measure REAL energy efficiency over its whole life cycle from mining to decommissioning.

This kind of analysis can be very subversive of the whole industrial and hi-tech paradigm because it helps calculate the real world costs and inefficiencies of industrial production. The basic fact is that ALL energy pollutes: even the materials for renewable energy technology need to be mined and industrially produced. Since most industrial, hi-tech activity and technology has high embodied energy (usually fossil) and is extremely energy-intensive, its pollution-intensity is often much more, and thus its REAL net energy yield often much less, than that of more ‘primitive’ methods of production.

For example, whereas labour-intensive, low-tech food production can produce positive energy yields (e.g. I calorie of input can produce 10-50 calories of food output in much indigenous and peasant farming), energy-intensive industrial agriculture and consumption inputs like machinery, fertilizers, chemicals, transport, refrigeration often produce negative energy yields.

For example, in the US food system as a whole it takes on average of over 7 calories of input to produce 1 calorie of food output. Thus, in net energy terms, small peasant agriculture is much more energy efficient than modern industrial agriculture and food distribution. (It is also usually more productive in terms of yield per acre). The same goes for small-scale fishing versus deep-sea trawling.

So what? Such real energy inefficiency means both a profligate waste of energy and more climate- changing carbon emissions. 17% of US energy goes into agriculture. The ‘feedlot and 5000 mile hamburger’ is not only full of unhealthy fat and sugar calories but also full of embodied fossil fuel energy that has contributed to the greenhouse effect. Half that can of coke is actually embodied oil. Mining, making and transporting the aluminium for the can caused immense carbon pollution. Drinking from cans and eating feedlot hamburgers helps create climate chaos. We are eating and drinking oil.

Another example is nuclear energy. Nuclear energy adherents are fond of presenting nuclear energy as ‘clean’ and ‘free of carbon emissions’. Their first rhetorical trick is to focus attention solely on the single nuclear plant and conveniently exclude the whole necessary nuclear cycle. (They of course also disregard the whole range of even more serious issues associated with radioactive emissions, meltdowns, waste disposal, weapons proliferation etc).

The second trick is to disregard embodied energy. When net and embodied energy analysis is applied to the whole nuclear cycle from uranium mining through fuel production and reprocessing via the power plants to waste ‘disposal’ and eventual decommissioning, immense amounts of fossil fuel subsidies are revealed which make nuclear energy highly polluting even in the greenhouse gas sense (and even questionable in some analyses in the pure net energy sense, especially if using low- grade uranium fuels).

The subversiveness of net and embodied energy, whole life cycle, analysis is thus obvious. Its core message is that there are no quick technical fixes, especially not large-scale, centralised highly energy-and capital-intensive ones. This of course also applies to large-scale, centralised renewable energy projects, the hope of many mainstream environmentalists.

Net energy analysis thus complements ecological arguments in other areas (e.g. food production, waste treatment) for more small-scale, decentralised, low-energy and direct-democratic solutions to the global eco-crisis. Small is indeed beautiful. Net energy analysis provides rational, quantitative support for local community empowerment and more democratic forms of production.

~ by Peter Lach-Newinsky on August 20, 2012.

2 Responses to “Net Energy & Embodied Energy: Subverting the Industrial Paradigm”

  1. Thanks Pete really enjoying this series, will try and share them with others

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