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Green hydrogen is the only realistic alternative to nuclear in areas which rely on wind power for renewable energy. Li-ion batteries can not economically create

by belorn 5y ago

Green hydrogen is the only realistic alternative to nuclear in areas which rely on wind power for renewable energy. Li-ion batteries can not economically create weeks long capacity of stored energy with a charge cycle of a few times a year. Wind does not have a day cycle as solar has. What green hydrogen need to do is become economical, and to my knowledge it is even more expensive per w/h then nuclear is.

ars 5y ago
Methane is a better fuel for that than hydrogen, you can make it from air plus energy (although not easily - there's not enough CO2 in the air for that). Or, more practically, coal and water and energy.
the8472 5y ago
"only realistic alternative" isn't quite right since it's one of several grid-scale storage options none of which have yet proven themselves to be economical.
Hermitian909 5y ago
For context, I'm a software developer who works with a lot of battery researchers. My understanding from them is that while Li-ion batteries cannot create weeks long capacity, rust batteries may be able to in the future. Check out Form Energy[0] for an early version of this, they're claiming ~100 hours of storage right now and if they're right about the science and can manage the engineering it could grow past a month. These batteries are challenging to run, a bit like a mini-chemical plant, but they do actually seem plausible. (No personal association with the company, some of my coworkers know the founders though) [0] https://formenergy.com/ https://formenergy.com/
- elihu 5y ago
  Interesting. Is the idea just that they're optimizing for cost, rather than optimizing for watt-hours per kilogram? I.e. if it doesn't matter how much it weighs, you can use a simple, cheap sort of battery that wouldn't be practical in a phone or a car?
  - Hermitian909 5y ago
    The price point is attractive but this is more than a clever insight into optimizing for different use cases. Previous attempts at these batteries have run into a lot of operational problems and have had trouble keeping the batteries up and running long enough for them to be useful. There's a lot of novel engineering and chemistry that's gone into operationalizing the system.
- belorn 5y ago
  Maybe you can answer a few question since the public available information is a bit limited. With a solar + Li-ion battery solution currently in use I often hear about 4hrs capacity at 80% output. How many years does it take for such installation to get a complete return of investment on the batteries, and how on average how low do they need to discharge every day? With those number we can then look at rust batteries. If we take a country like Germany we can estimate the longest period of low wind conditions in order to estimate how long capacity is required to have the country exclusively run on wind+batteries, and how often such periods occur to calculate the charge cycle. Can rust batteries create an return of investment within a reasonable time frame (with nuclear energy prices as the economical limit for what the market will bear). It would be very interesting to read a reply.
  - Hermitian909 5y ago
    I can't give you dollar values, but I think there are some ideas that might be informative: 1. The cost of these iron flow batteries is almost entirely in operations, the cost of battery material is negligible. It's early days so it's really hard to say how low ongoing costs for things like valves, pumps, control systems, etc. are going to be. 2. In principle, flow batteries shouldn't need to discharge at all. This is why researchers are confident they can create batteries with multi-month capacity.
    - belorn 5y ago
      I think there is a misunderstanding. If a battery solution is going to produce revenue outside of subsidizes it need to generate power. The number I would look towards is how many time the battery need to be charged and then discharged in order to repay the operational and initial construction costs. No discharge would mean no revenue and so either I am misunderstanding you or you me. If the cost can be reduced so much that a single discharge is all that is required to both repay the production cost and charge costs (assuming reasonable sell price for the energy) then it would be like a fuel and could be stockpiled as much as could be expected to be used. If the technology is so much in early development that there aren't much concrete numbers, could you at least give a suggestion about where the costs are right now? How far the economics of nuclear is the technology? For context of why I am asking this, my country has set the date 2030 as the year when no more IC cars might be sold. We do not have a date for IC power plants and we really should have. It is wrong to continue to burn fossil fuels just because the alternatives are more expensive.
p_l 5y ago
Dunno how it goes for other countries, but I spoke with someone who did professional analysis on green hydrogen from renewables for Poland... and it's not a good outlook. Essentially, in order to produce it in any reasonable quantity, assuming highest available efficiencies, required such massive overbuilding of renewables that economics started to take second position to just plain "zomg" effect. It got better if you combined it with nuclear, but there the free market that EU insists on in energy actually made it harder to achieve anything useful, so you end up with massive overbuilding still. It had a little chance if you overbuild wind & solar while also making it so you had nuclear providing close to 100% of the "base load" (defined as "floor in daily electricity consumption") while possibly providing green hydrogen as extra sink for renewables to recoup costs... but it still was problematic economically :(

by belorn 5y ago

ars 5y ago

Methane is a better fuel for that than hydrogen, you can make it from air plus energy (although not easily - there's not enough CO2 in the air for that). Or, more practically, coal and water and energy.

the8472 5y ago

"only realistic alternative" isn't quite right since it's one of several grid-scale storage options none of which have yet proven themselves to be economical.

Hermitian909 5y ago

For context, I'm a software developer who works with a lot of battery researchers. My understanding from them is that while Li-ion batteries cannot create weeks long capacity, rust batteries may be able to in the future. Check out Form Energy[0] for an early version of this, they're claiming ~100 hours of storage right now and if they're right about the science and can manage the engineering it could grow past a month. These batteries are challenging to run, a bit like a mini-chemical plant, but they do actually seem plausible. (No personal association with the company, some of my coworkers know the founders though) [0] https://formenergy.com/ https://formenergy.com/

elihu 5y ago
Interesting. Is the idea just that they're optimizing for cost, rather than optimizing for watt-hours per kilogram? I.e. if it doesn't matter how much it weighs, you can use a simple, cheap sort of battery that wouldn't be practical in a phone or a car?
- Hermitian909 5y ago
  The price point is attractive but this is more than a clever insight into optimizing for different use cases. Previous attempts at these batteries have run into a lot of operational problems and have had trouble keeping the batteries up and running long enough for them to be useful. There's a lot of novel engineering and chemistry that's gone into operationalizing the system.
belorn 5y ago
Maybe you can answer a few question since the public available information is a bit limited. With a solar + Li-ion battery solution currently in use I often hear about 4hrs capacity at 80% output. How many years does it take for such installation to get a complete return of investment on the batteries, and how on average how low do they need to discharge every day? With those number we can then look at rust batteries. If we take a country like Germany we can estimate the longest period of low wind conditions in order to estimate how long capacity is required to have the country exclusively run on wind+batteries, and how often such periods occur to calculate the charge cycle. Can rust batteries create an return of investment within a reasonable time frame (with nuclear energy prices as the economical limit for what the market will bear). It would be very interesting to read a reply.
- Hermitian909 5y ago
  I can't give you dollar values, but I think there are some ideas that might be informative: 1. The cost of these iron flow batteries is almost entirely in operations, the cost of battery material is negligible. It's early days so it's really hard to say how low ongoing costs for things like valves, pumps, control systems, etc. are going to be. 2. In principle, flow batteries shouldn't need to discharge at all. This is why researchers are confident they can create batteries with multi-month capacity.
  - belorn 5y ago
    I think there is a misunderstanding. If a battery solution is going to produce revenue outside of subsidizes it need to generate power. The number I would look towards is how many time the battery need to be charged and then discharged in order to repay the operational and initial construction costs. No discharge would mean no revenue and so either I am misunderstanding you or you me. If the cost can be reduced so much that a single discharge is all that is required to both repay the production cost and charge costs (assuming reasonable sell price for the energy) then it would be like a fuel and could be stockpiled as much as could be expected to be used. If the technology is so much in early development that there aren't much concrete numbers, could you at least give a suggestion about where the costs are right now? How far the economics of nuclear is the technology? For context of why I am asking this, my country has set the date 2030 as the year when no more IC cars might be sold. We do not have a date for IC power plants and we really should have. It is wrong to continue to burn fossil fuels just because the alternatives are more expensive.

p_l 5y ago

Dunno how it goes for other countries, but I spoke with someone who did professional analysis on green hydrogen from renewables for Poland... and it's not a good outlook. Essentially, in order to produce it in any reasonable quantity, assuming highest available efficiencies, required such massive overbuilding of renewables that economics started to take second position to just plain "zomg" effect. It got better if you combined it with nuclear, but there the free market that EU insists on in energy actually made it harder to achieve anything useful, so you end up with massive overbuilding still. It had a little chance if you overbuild wind & solar while also making it so you had nuclear providing close to 100% of the "base load" (defined as "floor in daily electricity consumption") while possibly providing green hydrogen as extra sink for renewables to recoup costs... but it still was problematic economically :(