102 comments on Understanding the current energy crisis in South Africa
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Forbes keeps featuring economists who say that fuel and GNP have decoupled to a greater degree in recent years in the U.S. But when you really look at the figures, it looks to me like the economic decoupling was based on increased debt, and is not sustainable. I expect we are reverting to the Hall & Cleveland model you cite.
They cite some efficiency improvements:
1. The switch from coal to oil gives a BTU to GNP boost (not good news for a future switch from oil back to coal).
2. The switch from coal or oil to electricity gives a BTU to GNP boost (great news for wind, nuke, solar PV).
But the main differences are explained away by looking at embodied energy in goods, which economists don't care to track, and household uses of energy, which don't impact GNP as much as industrial/commercial energy use.
So it is part hopeful (the future is electric!) and part not (GNP will decline with lower energy). But it would be very nice to have updated papers. I wish there was a 2007 version of the book!
"The switch from coal or oil to electricity gives a BTU to GNP boost"
This defies logic and is not true for coal. In switching from a primary fuel source, such as coal or oil, to a converted form of energy always results in energy losses. For example using electricty for boiler heat requires twice as much base energy (turning coal's btu's into electricity is only 35% efficient considering steam cycle losses, line losses and transformation losses) as compared with burning the coal for that same process heat. Home heating with electric heat pump using ground source would be about same efficiency as burning coal if heat pump has COP of at least 3.
Always? Surely it depends on the end use. Consider a train hauled by a coal fired steam locomotive, a diesel locomotive and an electric locomotive.
If the power station has a higher eficiency than an internal combustion engine or an open coal fire...
Most important.
Electricity is a carrier.
Like Hydrogen.
""The switch from coal or oil to electricity gives a BTU to GNP boost"
To which mbnewtrain replied,
"This defies logic and is not true for coal. In switching from a primary fuel source, such as coal or oil, to a converted form of energy always results in energy losses."
Correct. The primary fuel switch was the one to attribute the gain in BTU to GNP boost, i.e., natural gas.
RC