(this is my attempt to understand and summarize in less than 500 words, in order to make it accessible to as many people as possible, a very important issue I’ve read about in the sources quoted below. Comments and corrections are very welcome)

EROI (energy return on energy invested) is the ratio between the energy available for the economy and the energy it takes to produce that energy. An EROI of 100:1 means that the world gets 100 KWh for every KWh consumed to extract, process and distribute oil, carbon or any other power source, including renewable ones. High EROI, good. Low EROI, bad. For everybody.

According to some experts (see links below):

• worldwide, the average EROI of oil today is 20:1. Eighty years ago it was 100:1

• the estimated EROI for new oil, which often is five miles under the ocean or inside tar sands, is just 5:1.

• EROI for renewable energy sources is around 17:1. Better than future oil, but still (much) less than current and past oil.

This is terribly important for everybody because, if this is how things are today:

1. we will live the rest of our lives with material living standards lower than today simply because of lower EROI, that is even without financial crises, bailouts and attempts to avoid them via pension cuts, more taxes, privatizations and so on.

2. that is a purely physical, not political cause. What we do and use today needs a high EROI that doesn’t exist anymore, no matter who’s in power. Voting for another party doesn’t make oil easier and cheaper to extract

Point 1 is due to the fact that, as EROI decreases, the (current) economy loses capacity to generate wealth, because more and more energy every year goes away to produce… energy, instead of goods and services as in the past.

Point 2 means that it will make little or no difference if, for example, health care, schools, roads and other essential infrastructures will be run by governments or as private, for-profit businesses. In both cases, everything we’ll need in the future will have to become compatible with a much smaller EROI, or disappear.

That’s why those experts say that burning fossil fuel, ignoring climate change, and refusing to invest in renewable energy infrastructures is a sure way to make or keep a country “too poor to repair its buildings and bridges, too poor to educate its young to the highest standards”.

Instead, they say, regardless of national debts and related concerns (or, more exactly, because they’d be more symptoms than real causes) the only way to make sure we’ll have a decent standard of living in the next decades is to:

• remodel the whole society and all its infrastructures to work with the EROI rates of renewable energy sources (also because they could, over time, increase more than all the others).

• use as much fossil energy as possible, until it’s still around, for that purpose, instead of continuing to waste it as we are doing today, since coping with decreasing EROIs is the first priority.

Sources

• Is the austerity wave related to Peak Oil and a lower return on energy?

• The New Austerity and the EROI Squeeze

• The Link Between Peak Oil and Peak Debt. Part 1 and 2