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November 30, 2010

Nuclear Power should close the fuel cycle and energy return on fossil fuels has a large economic impact

1. Carey King at the University of Texas at Austin tries to make a case that is common at Peak Oil websites - lower energy return on fossil fuels causes economic recessions.
The worst recessions of the last 65 years were preceded by declines in energy quality for oil, natural gas, and coal. Energy quality is plotted using the Energy Intensity Ratio (EIR) for each fuel. Recessions are indicated by gray bars. In layman's terms, EIR measures how much profit is obtained by energy consumers relative to energy producers.The higher the EIR, the more economic value consumers (including businesses, governments and people) get from their energy.

In a paper published this November in the journal Environmental Research Letters, King introduced a new way to measure energy quality, the Energy Intensity Ratio (EIR), that is easier to calculate, highly correlated to EROI and in some ways more powerful than EROI. EIR measures how much profit is obtained by energy consumers relative to energy producers. The higher the EIR, the more economic value consumers (including businesses, governments and people) get from their energy.


EIR is proportional to EROI, meaning they rise and fall together, but the basic data behind the EIR calculations come out annually as opposed to every five years for EROI. EIR also gives insight into different parts of the supply chain such as at the refinery or at the gas pump, which are harder to study with EROI.

King's analysis suggests if EIR falls below a certain threshold, the economy stops growing. For example, in 1972, EIR for gasoline was 5.9 and in 2008 it was 5.5. During times of robust economic growth, such as the 1990s, EIR for gasoline was well over eight. Compare that to some estimates of EROI and EIR for corn ethanol of around one, and it's clear why corn ethanol has been widely criticized as a low quality energy source.

To get the U.S. economy growing again, King says Americans will have to produce and use energy more efficiently. That's essentially what the U.S. did after the last energy crisis by raising fuel efficiency standards for cars, increasing use of natural gas for electric power generation and developing new technologies such as Enhanced Oil Recovery to coax more oil out of the ground.

"If we aren't fundamentally changing the way we produce or consume energy now, don't expect the economy to grow as much as the past two decades," he says.

2. Benefits and concerns of a closed nuclear fuel cycle The article does not look at more advanced reactors but the existing reprocessing technology.

Reprocessing SNF into MOX fuel for LWRs can decrease the amount of fresh uranium ore needed annually by 25%. In addition, a single recycling of plutonium increases the energy derived from the original uranium by some 12%, and if the reprocessed uranium is also recycled by reenrichment by as much as 20%

If the additional cost is $450/lb of nuclear fuel separated, reprocessing technology will not be competitive until the price of natural uranium exceeds $160/lb

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