More on Ammonia
The Engineer Poet is dismissive of chemical energy transporters for renewable energy, whether hydrogen or ammonia (which after all, is a convenient way of transporting hydrogen). He has a point: direct use of electricity in, for example, fuel cells has much better efficiencies and therefore shouldbe cheaper.
Certainly generating electricity and then producing hydrogen by electrolysis is not on, in efficiency or cost terms. For thermochemical production of hydrogen using S-I or Ca-Br as a catalyst, however, from solar heat or off-peak nuclear, theoretical efficiencies are in the 40-50% range, which compares with electricity generation. These technologies have not yet been developed outside the lab. Why? –because steam cracking of natural gas to make hydrogen (the process used today) is 70-80% efficient, but that produces CO2, and would be pointless for a fuel anyway (just use the natural gas directly)
The key fact however is that there will be a continued need for chemical storage of energy . Most renewables are intermittent and/or a long way from the consumer, given long distance power transmission losses (or not even feasible – Australian solar power sold to China?) Direct distribution and storage of hydrogen is a nightmare. There seems no potential alternative for planes to a chemical fuel, and the elites of the world would rather wreck the world’s climate than give up flying. Yes, oil is a better storage medium than ammonia, but if anyone can come up with a better alternative that does not have those dratted C atoms somewhere in the molecule, please let me know.
Theoretical efficiency isn’t everything, otherwise the internal combustion engine and the steam turbine would be long gone. We have been promised fuel cells and high capacity traction batteries for decades – where are they? The world has got to change its whole energy and transportation within two decades or we are climatically wrecked - the less technological change or technical risk involved, the more likely this is to happen. This path minimises the risk, even if it less than ideally efficient.
Certainly generating electricity and then producing hydrogen by electrolysis is not on, in efficiency or cost terms. For thermochemical production of hydrogen using S-I or Ca-Br as a catalyst, however, from solar heat or off-peak nuclear, theoretical efficiencies are in the 40-50% range, which compares with electricity generation. These technologies have not yet been developed outside the lab. Why? –because steam cracking of natural gas to make hydrogen (the process used today) is 70-80% efficient, but that produces CO2, and would be pointless for a fuel anyway (just use the natural gas directly)
The key fact however is that there will be a continued need for chemical storage of energy . Most renewables are intermittent and/or a long way from the consumer, given long distance power transmission losses (or not even feasible – Australian solar power sold to China?) Direct distribution and storage of hydrogen is a nightmare. There seems no potential alternative for planes to a chemical fuel, and the elites of the world would rather wreck the world’s climate than give up flying. Yes, oil is a better storage medium than ammonia, but if anyone can come up with a better alternative that does not have those dratted C atoms somewhere in the molecule, please let me know.
Theoretical efficiency isn’t everything, otherwise the internal combustion engine and the steam turbine would be long gone. We have been promised fuel cells and high capacity traction batteries for decades – where are they? The world has got to change its whole energy and transportation within two decades or we are climatically wrecked - the less technological change or technical risk involved, the more likely this is to happen. This path minimises the risk, even if it less than ideally efficient.
Labels: Energy, Environment
posted by Total Issues at 10:47 pm
1 Comments:
We have been promised fuel cells and high capacity traction batteries for decades – where are they?
For my father-in-law's 90th birthday, in 1905, I gave him a reprint of a 1905 picture book of view of New York, his birthplace. The cover showed flying cars whizzing over the city at some future date now long since past.
Maybe the fuel cells and high capacity traction batteries are being withheld pending development of the flying cars. :-)
Best regards,
Collingwood
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