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These rates are somewhat useful if you have a flexible fossil backup, as wind and solar are not always available. If you are going 100% wind and solar, you nee

These rates are somewhat useful if you have a flexible fossil backup, as wind and solar are not always available. If you are going 100% wind and solar, you need to factor in the cost of energy storage as well as efficiency of storage. Then they will be much more expensive than gas.

kitkat_new 5y ago
please factor in the damage done by emitting CO2 into the atmosphere
cinntaile 5y ago
The optimal energy mix from a cost perspective is probably not 100% wind and solar so this doesn't sound like a realistic scenario. I am not aware of any good research that has tried to model that scenario but it probably exists. Some of the assumptions, like how much storage you would need, will have a huge impact on the outcome.
- pydry 5y ago
  You'd also need to take into account that a lot of demand can be time shifted to account for variability.
- pfdietz 5y ago
  The 100% renewable situation has indeed been modeled. Getting to 100% likely requires some kind of long term storage, like hydrogen. You can play with the numbers yourself using real weather data: https://model.energy/ https://model.energy/
simonh 5y ago
Which is why the title calls out battery storage, and the article spend about a third of it's word count talking about it. The price of battery storage has also fallen dramatically. One knock often made against solar+battery is the cost of replacing battery storage over the lifetime of the plant, but such criticisms often don't take into account the fact that replacement batteries in 5 and 10 years will likely cost a fraction of what they do now. The fact is a lot of countries already have enough gas plant capacity to act as 'peaker' plants to top up solar+battery.
- pfdietz 5y ago
  The cost of electrolysers is also falling rapidly, with China exports available for less than $300/kW. Green hydrogen is at the moment cheaper than gray hydrogen in Europe and the Middle East(!), and China. https://www.rechargenews.com/energy-transition/ukraine-war-green-hydrogen-now-cheaper-than-grey-in-europe-middle-east-and-china-bnef/2-1-1180320 https://www.rechargenews.com/energy-transition/ukraine-war-g...
  - pydry 5y ago
    Electrolysis was never the issue. The high cost of storing hydrogen and the high level of wastage is the main problem.
    - pfdietz 5y ago
      Hydrogen is very cheap to store, when stored underground, two orders of magnitude cheaper than storing energy in batteries (per kWh of storage capacity). As for wastage, if you are talking about round trip efficiency, that becomes relatively unimportant when renewable energy is cheap and the storage use case has few charge/discharge cycles (not daily storage, but long term, even seasonal, storage, and rare event backup, and of course supplying hydrogen to already existing industrial users of the gas.) Capital cost of electrolysers was indeed the issue, if you want to use overproduction from renewable sources to power them.
tim333 5y ago
You can start doing some interesting things if the cost of wind/solar is a half or quarter of regular power. Like using it to refine aluminium and then using that in batteries to generate energy https://news.ycombinator.com/item?id=26463249 https://news.ycombinator.com/item?id=26463249 That can store pretty much unlimited quantities though is not very efficient in terms of energy in and out.

kitkat_new 5y ago

please factor in the damage done by emitting CO2 into the atmosphere

cinntaile 5y ago

The optimal energy mix from a cost perspective is probably not 100% wind and solar so this doesn't sound like a realistic scenario. I am not aware of any good research that has tried to model that scenario but it probably exists. Some of the assumptions, like how much storage you would need, will have a huge impact on the outcome.

pydry 5y ago
You'd also need to take into account that a lot of demand can be time shifted to account for variability.
pfdietz 5y ago
The 100% renewable situation has indeed been modeled. Getting to 100% likely requires some kind of long term storage, like hydrogen. You can play with the numbers yourself using real weather data: https://model.energy/ https://model.energy/

simonh 5y ago

Which is why the title calls out battery storage, and the article spend about a third of it's word count talking about it. The price of battery storage has also fallen dramatically. One knock often made against solar+battery is the cost of replacing battery storage over the lifetime of the plant, but such criticisms often don't take into account the fact that replacement batteries in 5 and 10 years will likely cost a fraction of what they do now. The fact is a lot of countries already have enough gas plant capacity to act as 'peaker' plants to top up solar+battery.

pfdietz 5y ago
The cost of electrolysers is also falling rapidly, with China exports available for less than $300/kW. Green hydrogen is at the moment cheaper than gray hydrogen in Europe and the Middle East(!), and China. https://www.rechargenews.com/energy-transition/ukraine-war-green-hydrogen-now-cheaper-than-grey-in-europe-middle-east-and-china-bnef/2-1-1180320 https://www.rechargenews.com/energy-transition/ukraine-war-g...
- pydry 5y ago
  Electrolysis was never the issue. The high cost of storing hydrogen and the high level of wastage is the main problem.
  - pfdietz 5y ago
    Hydrogen is very cheap to store, when stored underground, two orders of magnitude cheaper than storing energy in batteries (per kWh of storage capacity). As for wastage, if you are talking about round trip efficiency, that becomes relatively unimportant when renewable energy is cheap and the storage use case has few charge/discharge cycles (not daily storage, but long term, even seasonal, storage, and rare event backup, and of course supplying hydrogen to already existing industrial users of the gas.) Capital cost of electrolysers was indeed the issue, if you want to use overproduction from renewable sources to power them.

tim333 5y ago

You can start doing some interesting things if the cost of wind/solar is a half or quarter of regular power. Like using it to refine aluminium and then using that in batteries to generate energy https://news.ycombinator.com/item?id=26463249 https://news.ycombinator.com/item?id=26463249 That can store pretty much unlimited quantities though is not very efficient in terms of energy in and out.