You may have heard statements like ‘the age of cheap energy is over’. Here’s why.
This little graphic shows equivalent returns on investment (EROI) for a range of energy sources. In 1930, for every unit of energy you spent prospecting and drilling, you’d get 100 back in gushing oil. Nowadays you have to drill deeper and search for longer, so you only get a return of 20:1 on your average oilfield.
Compare oil to the alternative fuels, and you’ll notice two things. 1) Oil is amazing. 2) Business as usual is going to be impossible after peak oil. Biodiesel only has a 2:1 return. Corn ethanol is actually energy negative, taking up more energy in plowing, fertilizing and harvesting than it gives back in fuel. There is no fuel that can take the place of oil and allow us to keep driving the way we do.
Electric cars might get us a little further, but we rely on coal and natural gas for electricity. Natural gas is the same as oil at around 20:1, coal slightly better, but a move to renewables would have to be absolutely massive to allow us to carry on living energy-intensive lives.
In short, there’s no shortcut here, no quick switch to renewables or alternative energy sources. The end of easy and cheap oil means changes to our lifestyles. Some of this will be efficiency gains, tightening up miles per gallon, better appliances, smarter homes. Some of it will be more radical change, re-designing cities so people live closer to work, re-localizing services, or eliminating wasteful trade (Britain imports the same amount of potatoes as it exports, for example).
This is why I choose not to fly, why I’m involved in Transition Towns, why I try to eat more seasonal food and grow more of my own – not out of some kind of eco-guilt or misplaced desire to save the planet, but because that’s the way the future lies.
EROI are notoriously difficult to work out, and estimates vary considerably. The ones in the graph are from the Transition Handbook. The Oil Drum has slightly different and more detailed figures here.