5 ms·

Capital cost is the initial cost to build this system. The figure for comes from figure 14. The cost estimates are $3,000 with current technology. This works ou

Capital cost is the initial cost to build this system. The figure for comes from figure 14. The cost estimates are $3,000 with current technology. This works out to $500 per KWh 20 years system. To match the lifespan of a nuclear plant (typically 60 to 80 years), this works out to $1,500 to $2,000 per KWh when factoring the limited life span of the storage. Regarding the reply with no response, timestamps get more coarse grained the further in the past you get. This reply could easily be weeks after my initial comment, and I would have explained how I arrived at these figures if I has read it. Meanwhile, glaring inaccuracies like calming that existing natural gas infrastructure can be used to transport hydrogen go unmentioned. Or that "hardly anyone is building nuclear" when in fact most of the world by population is. And if we're talking about cherry-picking pfdietz incessantly cherry picks the Vogtle and Flamanville plants as though they're representative of historic nuclear costs. You arrive at the conclusion that I'm arguing in bad faith, while conveniently ignoring these issues with the claims I'm arguing against. This exchange makes me sad, too. Solar and wind serve as useful temporary mitigation of carbon output, even though they don't pave a way to full decarbonization. A hydrogen economy has a place to fulfill demand where energy density is necessary, like in transportation. But trying to advocate pipe-dream projects like storing tens of terawatt hours worth of energy in hydrogen really makes me wonder whether solar and wind advocates really have a grasp on the engineering challenges they're facing. Especially when these plans rest on outright falsehoods, like the claim that we can using existing natural gas pipes for hydrogen.

reitzensteinm 6y ago
Right, that's the wrong figure to use in the context of the linked debate. It's the cost to operate the plant, including buying power at market rates. The "spilled wind" costs are the cost of the plant itself used in the manner described, which equals $1400/kW - actually, this is probably where you got the number originally - or $233/kWh. However, this is over the lifetime of the plant, meaning the storage is closer to $12/kWh per year. That's not exactly cheap. You have to overbuild renewables to have the extra energy to store in it, and it's probably only going to cycle a few dozen times a year. Plus the $12/kWh figure likely represents (the study does not specify) the energy of the gas before conversion back to electricity which is lossy. But adding extra storage is cheap compared to adding extra power, so unlike with lithium ion batteries you can actually feasibly build weeks worth of storage in to the system. So, I'm not trying to say the numbers are great. I'm not saying this is what we should do. But there's a vast gap between the $1400 you quoted and the $12 figure which - at least I believe - is the correct number to use for this discussion. There are absolutely tons of people (especially on HN) that trivialize the problems around rolling out renewables. Probably the majority of my posts on the topic have actually been on the other side, pointing out issues or complaining about subsidies instead of carbon taxes. But I really think you've gone 180 degrees in the other direction and the numbers you use make it seem an order of magnitude harder than it is. I think even more extreme than using the worst Western nuclear cost overruns as representative of the intrinsic cost of nuclear.
- pfdietz 6y ago
  For other cost figures for hydrogen storage, see the options and linked references at https://model.energy/ https://model.energy/ You can also use that site (and its weather time series) and play with the assumptions to see when nuclear can be made competitive with renewables + storage at supplying steady power output in various places, under a set of simplifying assumptions that tend to favor nuclear. You will find that hydrogen tends to be more important in high latitude places using wind.
- Manfredo_1 6y ago
  $12 per kilowatt hour, per year. You then need to multiply by the number of years that this storage system needs to be online. Again, if we're comparing against the alternative of building a nuclear plant, this is 60 to 80 years. Neglecting to factor in the required lifespan artificially deflates the price drastically. And again this figure of $12 per KWh per year is for the "spilled wind" scenario - that is, the assumption that the electricity input is provided at zero cost. The other poster also did more than just cherry pick particularly expensive plants. Among other things, they claimed that existing natural gas infrastructure can be used to transport hydrogen. This is simply untrue, hydrogen would corrode metal pipes used for natural gas. There's a factor of 2,000 less hydrogen pipelines. Probably even less overall infrastructure if you count natural gas transported by rail and LNG shipping.
  - pfdietz 6y ago
    > they claimed that existing natural gas infrastructure can be used to transport hydrogen. Are you referring to me there? Because I never said that.
    - Manfredo_1 6y ago
      > Geological formations suitable for storage of hydrogen are quite widespread. They're basically identical to the formations that are already used to store natural gas. https://news.ycombinator.com/item?id=24621709 https://news.ycombinator.com/item?id=24621709 > Not really. It has lower energy/mole. There is the possibility that if CO2 is present that microorganisms could react the two to make methane. But aside from that, where is this much greater complexity coming from? The equipment required for storing either is similar. https://news.ycombinator.com/item?id=24626876 https://news.ycombinator.com/item?id=24626876 > And did you read my post? There is already a great deal of equipment for manipulating hydrogen on an industrial scale. What, did you think they rip that stuff out every month? The issue you are raising is already well solved. https://news.ycombinator.com/item?id=24633530 https://news.ycombinator.com/item?id=24633530

reitzensteinm 6y ago

Right, that's the wrong figure to use in the context of the linked debate. It's the cost to operate the plant, including buying power at market rates. The "spilled wind" costs are the cost of the plant itself used in the manner described, which equals $1400/kW - actually, this is probably where you got the number originally - or $233/kWh. However, this is over the lifetime of the plant, meaning the storage is closer to $12/kWh per year. That's not exactly cheap. You have to overbuild renewables to have the extra energy to store in it, and it's probably only going to cycle a few dozen times a year. Plus the $12/kWh figure likely represents (the study does not specify) the energy of the gas before conversion back to electricity which is lossy. But adding extra storage is cheap compared to adding extra power, so unlike with lithium ion batteries you can actually feasibly build weeks worth of storage in to the system. So, I'm not trying to say the numbers are great. I'm not saying this is what we should do. But there's a vast gap between the $1400 you quoted and the $12 figure which - at least I believe - is the correct number to use for this discussion. There are absolutely tons of people (especially on HN) that trivialize the problems around rolling out renewables. Probably the majority of my posts on the topic have actually been on the other side, pointing out issues or complaining about subsidies instead of carbon taxes. But I really think you've gone 180 degrees in the other direction and the numbers you use make it seem an order of magnitude harder than it is. I think even more extreme than using the worst Western nuclear cost overruns as representative of the intrinsic cost of nuclear.

pfdietz 6y ago
For other cost figures for hydrogen storage, see the options and linked references at https://model.energy/ https://model.energy/ You can also use that site (and its weather time series) and play with the assumptions to see when nuclear can be made competitive with renewables + storage at supplying steady power output in various places, under a set of simplifying assumptions that tend to favor nuclear. You will find that hydrogen tends to be more important in high latitude places using wind.
Manfredo_1 6y ago
$12 per kilowatt hour, per year. You then need to multiply by the number of years that this storage system needs to be online. Again, if we're comparing against the alternative of building a nuclear plant, this is 60 to 80 years. Neglecting to factor in the required lifespan artificially deflates the price drastically. And again this figure of $12 per KWh per year is for the "spilled wind" scenario - that is, the assumption that the electricity input is provided at zero cost. The other poster also did more than just cherry pick particularly expensive plants. Among other things, they claimed that existing natural gas infrastructure can be used to transport hydrogen. This is simply untrue, hydrogen would corrode metal pipes used for natural gas. There's a factor of 2,000 less hydrogen pipelines. Probably even less overall infrastructure if you count natural gas transported by rail and LNG shipping.
- pfdietz 6y ago
  > they claimed that existing natural gas infrastructure can be used to transport hydrogen. Are you referring to me there? Because I never said that.
  - Manfredo_1 6y ago
    > Geological formations suitable for storage of hydrogen are quite widespread. They're basically identical to the formations that are already used to store natural gas. https://news.ycombinator.com/item?id=24621709 https://news.ycombinator.com/item?id=24621709 > Not really. It has lower energy/mole. There is the possibility that if CO2 is present that microorganisms could react the two to make methane. But aside from that, where is this much greater complexity coming from? The equipment required for storing either is similar. https://news.ycombinator.com/item?id=24626876 https://news.ycombinator.com/item?id=24626876 > And did you read my post? There is already a great deal of equipment for manipulating hydrogen on an industrial scale. What, did you think they rip that stuff out every month? The issue you are raising is already well solved. https://news.ycombinator.com/item?id=24633530 https://news.ycombinator.com/item?id=24633530