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Yes, it is conceivable that you could use cheap electricity from renewables, but it would have to be a lot cheaper than electricity from natural gas for it to m

by xyzzyz 6y ago

Yes, it is conceivable that you could use cheap electricity from renewables, but it would have to be a lot cheaper than electricity from natural gas for it to make economic sense, probably something on the order of 5-6x cheaper. You get a factor of 3x just by using natural gas to heat directly, and then you need to account for bigger capital expenses for building plant and storage, because the cheap renewables are not available round the clock, so your production capacity must be significantly higher to produce more when they are available, to match the same average production of a standard natural gas plant, which can have smaller reactors etc but work around the clock. I think hitting 5-6x cheaper costs on average might be hard.

ncmncm 6y ago
It is a mystery to me why you keep talking about heat. Heat is the lowest grade of energy, and least useful. Not taking a wasteful detour through heat is the first rule of efficient conversion. While duty cycle of solar is under 50%, when there is not sunshine there is very often wind. So 50% idle capacity is unlikely. Catalytic conversion of electricity to hydrogen will probably exceed 90% efficiency in short order, and from H2 back to electric via fuel cell is already over 90%. Liquified and pumped into aircraft, nothing comes close to H2 for efficiency. Likewise, in rockets. When we finally get sensible carbon taxation, 6x cheaper than CH4 will be easy to achieve.
- xyzzyz 6y ago
  It is a mystery to me why you keep talking about heat. Heat is the lowest grade of energy, and least useful. Not taking a wasteful detour through heat is the first rule of efficient conversion. That’s because the alternative process to electrolysis of producing hydrogen, the steam reforming, uses heat, not electricity. I keep talking about heat, because electricity from solar or wind is competing not with electricity from natural gas, but with heat from natural gas. Given typical conversion efficiency of 20-30%, this means that the heat from natural gas is at the very least 3-5 times cheaper than electricity from natural gas, and in fact it’s even cheaper than that, because you don’t need expensive turbines to generate heat from natural gas, reducing your capital and maintenance costs even more. EIA doesnt expect costs of electricity from solar to go below electricity from natural gas by 2040 at all, much less 6 times. When we finally get sensible carbon taxation, 6x cheaper than CH4 will be easy to achieve. Yes, if you put a finger on a scale, you can achieve any result that you want.
  - ncmncm 6y ago
    I guess you meant to say "finger off the scale", after carbon burners are no longer permitted to externalize environmental damage for free. If it had been collected starting when we knew it would cause catastrophe, and commensurate with the catastrophe, we would be carbon-negative by now. Clawing it back, retroactively, from those enriched by causing the catastrophe would be helpful even now.

by xyzzyz 6y ago

ncmncm 6y ago

It is a mystery to me why you keep talking about heat. Heat is the lowest grade of energy, and least useful. Not taking a wasteful detour through heat is the first rule of efficient conversion. While duty cycle of solar is under 50%, when there is not sunshine there is very often wind. So 50% idle capacity is unlikely. Catalytic conversion of electricity to hydrogen will probably exceed 90% efficiency in short order, and from H2 back to electric via fuel cell is already over 90%. Liquified and pumped into aircraft, nothing comes close to H2 for efficiency. Likewise, in rockets. When we finally get sensible carbon taxation, 6x cheaper than CH4 will be easy to achieve.

xyzzyz 6y ago
It is a mystery to me why you keep talking about heat. Heat is the lowest grade of energy, and least useful. Not taking a wasteful detour through heat is the first rule of efficient conversion. That’s because the alternative process to electrolysis of producing hydrogen, the steam reforming, uses heat, not electricity. I keep talking about heat, because electricity from solar or wind is competing not with electricity from natural gas, but with heat from natural gas. Given typical conversion efficiency of 20-30%, this means that the heat from natural gas is at the very least 3-5 times cheaper than electricity from natural gas, and in fact it’s even cheaper than that, because you don’t need expensive turbines to generate heat from natural gas, reducing your capital and maintenance costs even more. EIA doesnt expect costs of electricity from solar to go below electricity from natural gas by 2040 at all, much less 6 times. When we finally get sensible carbon taxation, 6x cheaper than CH4 will be easy to achieve. Yes, if you put a finger on a scale, you can achieve any result that you want.
- ncmncm 6y ago
  I guess you meant to say "finger off the scale", after carbon burners are no longer permitted to externalize environmental damage for free. If it had been collected starting when we knew it would cause catastrophe, and commensurate with the catastrophe, we would be carbon-negative by now. Clawing it back, retroactively, from those enriched by causing the catastrophe would be helpful even now.