The issue of energy return on energy investment (EROEI) requires careful handling.
First one thinks that difficult resources, such as tar sands, greatly increase the amount of oil available. One realises that they need a lot of energy to extract the oil. Knowing the history of the industrial revolution, one recalls that the early steam engines, that were used for pumping water out of coal mines, were terribly inefficient, but that didn’t matter very much because they were located at the pit head and had cheap access to the coal that they were helping to mine. So one brushes off concerns about needing to use a lot of oil to extract oil from tar sands.
On second thoughts one sees a potential problem. Where do you get the oil that you use to help you get more oil? If the EROEI is reasonably high this is a minor adjustment. If it takes 1 barrel to extract 10 barrels, you don’t get to ship 10 barrels out of the oil field. You have to replace the barrel you used. You ship 9 barrels for every 10 extracted, a minor correction. Once the EROEI falls to 1.1 your oil industry is in deep trouble. It is taking you 10 barrels to extract 11. What you extract barely covers what you burned to extract it. You only ship 11-10=1 barrel. Extracting 11 barrels to get one is going to push the price up eleven fold and deplete the resource eleven times as fast as you were expecting.
On first thoughts any EROEI above zero is useful. On second thoughts the lower limit is at an EROEI of 1 and actually one needs to be well above that.
On third thoughts one notices that there are other sources of energy than oil. While oil is cheap, it gets used as a general purpose source of energy, but it is only really essential as a transport fuel. France gets 80% of its electricity from nuclear power. I suspect that they are cooking the books and subsidizing nuclear electricity. But notice that countries can only give big, misleading subsidies to minority components of their industrial base. They still have to have viable industries from which wealth can be transferred. If the French government were giving a big subsidy to nuclear power, such that it is misleading about the financial viability of nuclear power, the country would be noticeably impoverished by the economic distortion. It isn’t.
So, on third thoughts, as oil prices rise one moves to getting the energy for extracting oil from other sources. An EROEI of 0.5 implies using 2 Joules of electricity from nuclear fission to get 1 Joule’s worth of oil for transport fuel. On that basis people will continue to drive cars and fly in airplanes, although it gets a lot dearer. Maybe people actually switch to batteries for wheeled transport and save flying for special occasions. The point is that EROEI = 1 doesn’t mark the end of civilisation. It marks the point at which oil stops being a source of energy and becomes an energy storage medium, in direct competition with batteries. It is still available for transport applications which need very high density energy storage for, for example, transatlantic flights.
The issue of energy return on energy investment (EROEI) requires careful handling.
First one thinks that difficult resources, such as tar sands, greatly increase the amount of oil available. One realises that they need a lot of energy to extract the oil. Knowing the history of the industrial revolution, one recalls that the early steam engines, that were used for pumping water out of coal mines, were terribly inefficient, but that didn’t matter very much because they were located at the pit head and had cheap access to the coal that they were helping to mine. So one brushes off concerns about needing to use a lot of oil to extract oil from tar sands.
On second thoughts one sees a potential problem. Where do you get the oil that you use to help you get more oil? If the EROEI is reasonably high this is a minor adjustment. If it takes 1 barrel to extract 10 barrels, you don’t get to ship 10 barrels out of the oil field. You have to replace the barrel you used. You ship 9 barrels for every 10 extracted, a minor correction. Once the EROEI falls to 1.1 your oil industry is in deep trouble. It is taking you 10 barrels to extract 11. What you extract barely covers what you burned to extract it. You only ship 11-10=1 barrel. Extracting 11 barrels to get one is going to push the price up eleven fold and deplete the resource eleven times as fast as you were expecting.
On first thoughts any EROEI above zero is useful. On second thoughts the lower limit is at an EROEI of 1 and actually one needs to be well above that.
On third thoughts one notices that there are other sources of energy than oil. While oil is cheap, it gets used as a general purpose source of energy, but it is only really essential as a transport fuel. France gets 80% of its electricity from nuclear power. I suspect that they are cooking the books and subsidizing nuclear electricity. But notice that countries can only give big, misleading subsidies to minority components of their industrial base. They still have to have viable industries from which wealth can be transferred. If the French government were giving a big subsidy to nuclear power, such that it is misleading about the financial viability of nuclear power, the country would be noticeably impoverished by the economic distortion. It isn’t.
So, on third thoughts, as oil prices rise one moves to getting the energy for extracting oil from other sources. An EROEI of 0.5 implies using 2 Joules of electricity from nuclear fission to get 1 Joule’s worth of oil for transport fuel. On that basis people will continue to drive cars and fly in airplanes, although it gets a lot dearer. Maybe people actually switch to batteries for wheeled transport and save flying for special occasions. The point is that EROEI = 1 doesn’t mark the end of civilisation. It marks the point at which oil stops being a source of energy and becomes an energy storage medium, in direct competition with batteries. It is still available for transport applications which need very high density energy storage for, for example, transatlantic flights.