6 ms·

Why is using stored renewable energy (e.g., chemical, physical) not an option?

by RandomLensman 2y ago

CamperBob2 2y ago
I don't know. Why aren't they? We could be using them now at scale, if they were, but we're not.
- RandomLensman 2y ago
  I guess, fair amount of NIMBY there (if you don't like wind power next to you, you also don't like storage next to you in a lot of cases), some subsidies might also have had some effects on storage vs production built. Not everything is capital efficient in all places, too, of course.
- oezi 2y ago
  But we are. The world is moving rapidly there. 66% of daily electricity in Germany is renewable. California is building batteries at neck breaking speeds: https://www.gov.ca.gov/2024/04/25/california-achieves-major-clean-energy-victory-10000-megawatts-of-battery-storage/ https://www.gov.ca.gov/2024/04/25/california-achieves-major-...
  - Manuel_D 2y ago
    The point is, removing the remaining 1/3rd of fossil fuel production becomes a lot harder. The issue is that renewables other than hydro and geothermal are all intermittent. Build as many solar panels as you want, you're not going to satisfy nighttime demand without massive storage facilities. 10 GWh of storage is peanuts. That's what one nuclear plant produces in about 5 hours. The USA uses 500 GWh of electricity per hour.
    - oezi 2y ago
      The first step is just to build enough renewables and enough battery to last one average day. That gets you to 95% of reducing CO2. Then you can think about if it even makes sense to replace those cloudy yet/windless days. We just need to spend on the most economic places to save CO2.
      - Manuel_D 2y ago
        World electricity consumption is 60,000 GWh per day. "Last one average day" is much greater than existing battery production can satisfy - it's around 40x annual battery production to achieve just 12 hours of storage. And that's ignoring the fact that electric vehicles are consuming the vast majority of battery production. Making any serious efforts towards grid-storage would set back EV adoption.
        oezi 2y ago
        It doesn't have to be so bleak. - Every EV purchased can be part of the solution by supporting vehicle to grid charging. - Annual production capacity can increase. IEA estimates 6,000 GWh per year will be manufactured in 2030. I am sure it will grow further. - We need way less than 60,000 GWh to provide batteries for an average day, because solar, wind, hydro are covering part of this.
        Manuel_D 2y ago
        Using EV as grid storage is not feasible. One, many vehicles are used for business, utilities, and public transit. So they'll be driven during the day, and charged at night. This is going to increase load during hours of non-production, the opposite of storage. Two, no san grid operator is going to accept a situation where much of their storage capacity will just drive away for vacation, or in anticipation of a disaster. The predicted exponential rise is still an order of magnitude less than the scale required, and the vast majority of it is not going to grid storage. Wind is subject to intermittency, too. It's not a magic bullet that eliminates storage. Unless you're overprovisioning wind by a factor of 10 (in which case it's not cheap anymore), you'll still have weeks-long stretches where there is insufficient energy. Hydro is really the only non-intermittent carbon-free energy source besides geothermal and nuclear power. The reality is that wind and solar are only cheap in the context of a non-intermittent source that can fill in for the intermittency of renewable production. Running a minority of your grid on solar and wind, supplementing gas plants is one thing. Running a grid mostly wind and solar is totally different beast.
  - lucidludic 2y ago
    > But we are. The world is moving rapidly there. 66% of daily electricity in Germany is renewable. In 2023 renewables made up 52% of power production in Germany: https://www.cleanenergywire.org/factsheets/germanys-energy-consumption-and-power-mix-charts https://www.cleanenergywire.org/factsheets/germanys-energy-c... The remainder being almost entirely fossil fuels including 25.6% from burning coal, largely necessary because Germany chose to phase out nuclear energy. Electricity is not the whole story either. Renewables accounted for less than 20% of Germany's primary energy consumption in 2023.
godelski 2y ago
It is. But the issue is that storage systems are quite expensive and not nearly as green as what feeds them. Interestingly when you include these nuclear is much more competitive. But this depends on the studies and you should pay very close to the assumptions those studies make. Regardless, these are always in aggregate. So even with biases the case always is made that when considering the heterogenous nature of environment that some places will favor nuclear and others will favor renewables (which is again nonhomogeneous as wind and solar aren't always strongly coupled and certainly hydro isn't available everywhere). This is true for the studies that show the best results for nuclear and the studies that show the worst. A major problem with these discussions is people are operating on aggregate assumptions and acting as if it's one or the other. One interesting part that people might not be aware of is hydrogen production. Nuclear is often argued as a base load so the question is what to do when the sun is shining and wind is strong? You can throttle nuclear but this is not cost effective. But you can in turn produce hydrogen, which can even be used to cheapen and make renewable storage more green. One of the biggest concerns here though is that hydrogen production might be so valuable that nuclear producers might favor that over providing base load. So as everything, the reality is much more complicated than our general conversations reveal. It's even far more complicated than what can be included in a HN reply. But I hope I gave a sufficient response than can also point to more information.
- natmaka 2y ago
  Obtaining electricity thanks to industrial renewable (see Lazard's LCOE) is way (and more and more) cheaper than with nuclear. There are many ways to alleviate unwanted impacts of 'intermittency' (PEM membranes, central plant enabling many sites exposed to different wind regimes to feed it, batteries...) Hydrogen overproduction (from the grid perspective) isn't a challenge because various industries need huge amounts (~94 millions metric tons/an) of it. Therefore the 'hydrogen' approach favors renewable sources.
  - yawaramin 2y ago
    Most of what you are talking about is theoretical and the real costs will become apparent only once someone tries actually doing it. Meanwhile, nuclear power is proven technology for decades, worldwide.
Manuel_D 2y ago
Hydropower storage is geographically limited. Chemical storage is not available at the scale required. Plus most batteries produced are going to EVs. Remember, the world uses ~60 TWh of energy per day. And it's not not the day and night cycle that needs to be smoothed out, it's also seasonal fluctuations that can last for weeks. All the other options haven't been built at scale. Hydrogen storage, giant flywheels, compressed air have all been suggested, but aren't deployed widely enough to prove viability.

Why is using stored renewable energy (e.g., chemical, physical) not an option?

CamperBob2 2y ago

I don't know. Why aren't they? We could be using them now at scale, if they were, but we're not.

RandomLensman 2y ago
I guess, fair amount of NIMBY there (if you don't like wind power next to you, you also don't like storage next to you in a lot of cases), some subsidies might also have had some effects on storage vs production built. Not everything is capital efficient in all places, too, of course.
oezi 2y ago
But we are. The world is moving rapidly there. 66% of daily electricity in Germany is renewable. California is building batteries at neck breaking speeds: https://www.gov.ca.gov/2024/04/25/california-achieves-major-clean-energy-victory-10000-megawatts-of-battery-storage/ https://www.gov.ca.gov/2024/04/25/california-achieves-major-...
- Manuel_D 2y ago
  The point is, removing the remaining 1/3rd of fossil fuel production becomes a lot harder. The issue is that renewables other than hydro and geothermal are all intermittent. Build as many solar panels as you want, you're not going to satisfy nighttime demand without massive storage facilities. 10 GWh of storage is peanuts. That's what one nuclear plant produces in about 5 hours. The USA uses 500 GWh of electricity per hour.
  - oezi 2y ago
    The first step is just to build enough renewables and enough battery to last one average day. That gets you to 95% of reducing CO2. Then you can think about if it even makes sense to replace those cloudy yet/windless days. We just need to spend on the most economic places to save CO2.
    - Manuel_D 2y ago
      World electricity consumption is 60,000 GWh per day. "Last one average day" is much greater than existing battery production can satisfy - it's around 40x annual battery production to achieve just 12 hours of storage. And that's ignoring the fact that electric vehicles are consuming the vast majority of battery production. Making any serious efforts towards grid-storage would set back EV adoption.
      - oezi 2y ago
        It doesn't have to be so bleak. - Every EV purchased can be part of the solution by supporting vehicle to grid charging. - Annual production capacity can increase. IEA estimates 6,000 GWh per year will be manufactured in 2030. I am sure it will grow further. - We need way less than 60,000 GWh to provide batteries for an average day, because solar, wind, hydro are covering part of this.
        Manuel_D 2y ago
        Using EV as grid storage is not feasible. One, many vehicles are used for business, utilities, and public transit. So they'll be driven during the day, and charged at night. This is going to increase load during hours of non-production, the opposite of storage. Two, no san grid operator is going to accept a situation where much of their storage capacity will just drive away for vacation, or in anticipation of a disaster. The predicted exponential rise is still an order of magnitude less than the scale required, and the vast majority of it is not going to grid storage. Wind is subject to intermittency, too. It's not a magic bullet that eliminates storage. Unless you're overprovisioning wind by a factor of 10 (in which case it's not cheap anymore), you'll still have weeks-long stretches where there is insufficient energy. Hydro is really the only non-intermittent carbon-free energy source besides geothermal and nuclear power. The reality is that wind and solar are only cheap in the context of a non-intermittent source that can fill in for the intermittency of renewable production. Running a minority of your grid on solar and wind, supplementing gas plants is one thing. Running a grid mostly wind and solar is totally different beast.
- lucidludic 2y ago
  > But we are. The world is moving rapidly there. 66% of daily electricity in Germany is renewable. In 2023 renewables made up 52% of power production in Germany: https://www.cleanenergywire.org/factsheets/germanys-energy-consumption-and-power-mix-charts https://www.cleanenergywire.org/factsheets/germanys-energy-c... The remainder being almost entirely fossil fuels including 25.6% from burning coal, largely necessary because Germany chose to phase out nuclear energy. Electricity is not the whole story either. Renewables accounted for less than 20% of Germany's primary energy consumption in 2023.

godelski 2y ago

It is. But the issue is that storage systems are quite expensive and not nearly as green as what feeds them. Interestingly when you include these nuclear is much more competitive. But this depends on the studies and you should pay very close to the assumptions those studies make. Regardless, these are always in aggregate. So even with biases the case always is made that when considering the heterogenous nature of environment that some places will favor nuclear and others will favor renewables (which is again nonhomogeneous as wind and solar aren't always strongly coupled and certainly hydro isn't available everywhere). This is true for the studies that show the best results for nuclear and the studies that show the worst. A major problem with these discussions is people are operating on aggregate assumptions and acting as if it's one or the other. One interesting part that people might not be aware of is hydrogen production. Nuclear is often argued as a base load so the question is what to do when the sun is shining and wind is strong? You can throttle nuclear but this is not cost effective. But you can in turn produce hydrogen, which can even be used to cheapen and make renewable storage more green. One of the biggest concerns here though is that hydrogen production might be so valuable that nuclear producers might favor that over providing base load. So as everything, the reality is much more complicated than our general conversations reveal. It's even far more complicated than what can be included in a HN reply. But I hope I gave a sufficient response than can also point to more information.

natmaka 2y ago
Obtaining electricity thanks to industrial renewable (see Lazard's LCOE) is way (and more and more) cheaper than with nuclear. There are many ways to alleviate unwanted impacts of 'intermittency' (PEM membranes, central plant enabling many sites exposed to different wind regimes to feed it, batteries...) Hydrogen overproduction (from the grid perspective) isn't a challenge because various industries need huge amounts (~94 millions metric tons/an) of it. Therefore the 'hydrogen' approach favors renewable sources.
- yawaramin 2y ago
  Most of what you are talking about is theoretical and the real costs will become apparent only once someone tries actually doing it. Meanwhile, nuclear power is proven technology for decades, worldwide.

Manuel_D 2y ago

Hydropower storage is geographically limited. Chemical storage is not available at the scale required. Plus most batteries produced are going to EVs. Remember, the world uses ~60 TWh of energy per day. And it's not not the day and night cycle that needs to be smoothed out, it's also seasonal fluctuations that can last for weeks. All the other options haven't been built at scale. Hydrogen storage, giant flywheels, compressed air have all been suggested, but aren't deployed widely enough to prove viability.