8 ms·

If solar were free, but we still needed to pay for battery storage, how would it then compare in cost to fuel-based alternatives (fossil fuel, nuclear etc)?

kragen 6y ago
It's a little hard to predict how the price of battery storage will change as demand for it increases by orders of magnitude, and also how energy usage patterns will change as the relative cost of nighttime energy usage goes up. I've explored these themes in the past in a number of notes. https://dercuano.github.io/topics/solar.html https://dercuano.github.io/topics/solar.html and in particular https://dercuano.github.io/notes/energy-storage-efficiency.html https://dercuano.github.io/notes/energy-storage-efficiency.h..., https://dercuano.github.io/notes/heliogen.html https://dercuano.github.io/notes/heliogen.html, and https://dercuano.github.io/notes/lithium-supplies.html https://dercuano.github.io/notes/lithium-supplies.html. https://dercuano.github.io/notes/balcony-battery.html https://dercuano.github.io/notes/balcony-battery.html and https://dercuano.github.io/notes/the-suburbean.html https://dercuano.github.io/notes/the-suburbean.html explore the question at the household scale. More recently, https://news.ycombinator.com/item?id=26219344 https://news.ycombinator.com/item?id=26219344 and https://news.ycombinator.com/item?id=26229595 https://news.ycombinator.com/item?id=26229595 explore this question in more detail, and https://news.ycombinator.com/item?id=26308189 https://news.ycombinator.com/item?id=26308189 explores specifically what it would cost for California to switch to an all-solar grid with only battery storage over the next decade. David MacKay wrote a wonderful and highly accessible overview of the topic in 02009 as part of his excellent book, Sustainable Energy Without the Hot Air, which is specifically about sustainable energy in Britain. Unfortunately it needs to be updated—in particular, it doesn't consider utility-scale battery facilities at all—and he is sadly no longer in a position to update it. The license does permit third parties to provide an updated version, but he did not publish the source code. Still, here it is: https://www.withouthotair.com/c26/page_186.shtml https://www.withouthotair.com/c26/page_186.shtml
- jessaustin 6y ago
  ...how energy usage patterns will change as the relative cost of nighttime energy usage goes up. My fondest dream is that they'll stop dotting the countryside with those ridiculous pole-mounted "security" lights, and we'll be able to experience nighttime again.
  - kragen 6y ago
    I would love this, but battery costs and solar-panel costs are nowhere near high enough to cause it to happen in order to save on the power bill. They probably never will be.
  - sparker72678 6y ago
    I think our best hope for this working out is from the (very slowly) growing view of light pollution as the actual _pollution_ that it is. I would absolutely love this, but I still find it hard to imagine this changing in any significant way in the next 25 years.
kleton 6y ago
Would need $20/KWh battery storage to be competitive with nuclear for baseload according to https://www.cell.com/joule/fulltext/S2542-4351(19)30300-9 https://www.cell.com/joule/fulltext/S2542-4351(19)30300-9 At the moment, we're at about $800/KWh.
- jxidjhdhdhdhfhf 6y ago
  Aren't car battery packs under $100/KWh? Is there some other factor which drives up the price for grid level storage?
  - manfredo 6y ago
    The factor that drives up price for grid level storage is scale. Only ~300 GWh worth of batteries is produced globally each year. The world uses 2.5 TWh of electricity each hour. If anyone tries to install battery storage at a significant scale, demand will vastly outstrip supply and drive prices up.
    - deleted 6y ago
      [deleted]
    - jeremysalwen 6y ago
      Assuming there aren't economies of scale. Demand for solar had gone way up in recent decades (e.g. in germany, before it was cheap), and the price subsequently went down.
      - mlyle 6y ago
        It's not clear batteries will do the same. While there's been effort to make batteries less reliant on scarce natural resources and mining, there's no guarantee we really get there. If we don't, price can be expected to go up, not down, with scale. I would bet on price going down slightly with scale, but one can't really tell now what will happen: it might go up a lot, it might go down a lot, or it might stay flat.
andechs 6y ago
Not all battery storage needs to be electrochemical - hydroelectric dams work amazingly as pumped storage batteries (although site specific).
- amelius 6y ago
  What is the typical efficiency of a charge-discharge cycle?
  - vkou 6y ago
    It's relatively high, the problem is that building new dams is an environmental disaster, and existing dams are two orders of magnitude below needed capacity. Also, hydro dams kill a lot of people when they have accidents.
    - chrisco255 6y ago
      Do you have to dam a river to store energy in this way? Can they just build water towers that pull water from underground up into a tank and release it via gravity to generate power when needed?
      - marvin 6y ago
        Not enough energy. Hydropower reservoirs are typically many square kilometers of water surface, depth > 10 meters on average and a height differential on the order of 100 meters or more. Vary parameters according to geography, but it's not something that can be built without using geology for support.
        chrisco255 6y ago
        Yeah but in this case, the hydropower is being used for power generation, not as a battery supplement for solar/wind, right? Does it need to be so massive to act as a replacement/alternative for Lithium battery banks?
turtlebits 6y ago
People use way too much power for battery storage to be viable. The average household consumes 28.9kwh in a day (in 2017), which is way more than rooftop solar can provide. Maybe when we have smaller houses and don't have a bajillion devices plugged in all the time.
- cronix 6y ago
  It's amazing how much less of something you use when you don't have basically an endless, cheap supply of it. You tend to conserve a lot more because you know it's finite and will run out if you use too much.
- coderintherye 6y ago
  The majority of solar comes from Utility scale about 60/40 vs. rooftop solar: https://en.wikipedia.org/wiki/Solar_power_in_the_United_States#Solar_PV_by_type https://en.wikipedia.org/wiki/Solar_power_in_the_United_Stat...
  - flgb 6y ago
    Not in Australia, where we have much more roof-top solar (and which is less than half-the-price installed of roof-top in the US)
    - kragen 6y ago
      Interesting! Do you have any idea why it's so much cheaper?
      - dragonwriter 6y ago
        Shipping costs from China, who is the source of key materials?
        kragen 6y ago
        You might think so, but no. It's the wrong order of magnitude. That could add maybe US$2000 per TEU, which is 21 tonnes of cargo such as solar panels. You can ship a TEU anywhere in the world for US$3000 or less. A 1m² solar panel might weigh 20 kg, so that's roughly 1000 solar pannels, or US$2 per solar panel. That solar panel is about 200 Wp, so this works out to US$0.01 of shipping cost per peak watt. Or less. The solar module itself costs some US$0.18/Wp wholesale (the article cites higher prices, but see http://pvinsights.com/ http://pvinsights.com/ https://www.solarserver.de/pv-modulpreise/ https://www.solarserver.de/pv-modulpreise/ https://www.energytrend.com/solar-price.html https://www.energytrend.com/solar-price.html for more detailed and reliable pricing info), and the whole installation including the panels maybe US$0.50/Wp. So there's no way that an extra US$0.01/Wp could double the cost of the installation. Bump it by 2% maybe. China isn't the source of key materials. There aren't any key materials; the ingredients in PV cells, except for silver, are abundant everywhere. It's the source of the fully manufactured photovoltaic modules, a finished product that you can prop up in the sun and connect to a battery through a diode. If shipping costs were so high relative to the value of the finished product, every country would have its own solar-cell manufacturing plants, the way every country has its own liquid-oxygen plants, and there wouldn't be such a thing as a worldwide concentration of PV manufacturing in China.
jxidjhdhdhdhfhf 6y ago
Might be of interest to you: the think tank Rethinkx is forecasting wind and solar + lithium ion batteries will be cheaper than continuing to run already existing coal and gas power plants by 2030. They believe this will cause the capital invested in other types of power plants to become "stranded". https://youtu.be/6zgwiQ6BoLA https://youtu.be/6zgwiQ6BoLA
pfdietz 6y ago
https://model.energy/ https://model.energy/ Play with the assumptions and find out.

kragen 6y ago

It's a little hard to predict how the price of battery storage will change as demand for it increases by orders of magnitude, and also how energy usage patterns will change as the relative cost of nighttime energy usage goes up. I've explored these themes in the past in a number of notes. https://dercuano.github.io/topics/solar.html https://dercuano.github.io/topics/solar.html and in particular https://dercuano.github.io/notes/energy-storage-efficiency.html https://dercuano.github.io/notes/energy-storage-efficiency.h..., https://dercuano.github.io/notes/heliogen.html https://dercuano.github.io/notes/heliogen.html, and https://dercuano.github.io/notes/lithium-supplies.html https://dercuano.github.io/notes/lithium-supplies.html. https://dercuano.github.io/notes/balcony-battery.html https://dercuano.github.io/notes/balcony-battery.html and https://dercuano.github.io/notes/the-suburbean.html https://dercuano.github.io/notes/the-suburbean.html explore the question at the household scale. More recently, https://news.ycombinator.com/item?id=26219344 https://news.ycombinator.com/item?id=26219344 and https://news.ycombinator.com/item?id=26229595 https://news.ycombinator.com/item?id=26229595 explore this question in more detail, and https://news.ycombinator.com/item?id=26308189 https://news.ycombinator.com/item?id=26308189 explores specifically what it would cost for California to switch to an all-solar grid with only battery storage over the next decade. David MacKay wrote a wonderful and highly accessible overview of the topic in 02009 as part of his excellent book, Sustainable Energy Without the Hot Air, which is specifically about sustainable energy in Britain. Unfortunately it needs to be updated—in particular, it doesn't consider utility-scale battery facilities at all—and he is sadly no longer in a position to update it. The license does permit third parties to provide an updated version, but he did not publish the source code. Still, here it is: https://www.withouthotair.com/c26/page_186.shtml https://www.withouthotair.com/c26/page_186.shtml

jessaustin 6y ago
...how energy usage patterns will change as the relative cost of nighttime energy usage goes up. My fondest dream is that they'll stop dotting the countryside with those ridiculous pole-mounted "security" lights, and we'll be able to experience nighttime again.
- kragen 6y ago
  I would love this, but battery costs and solar-panel costs are nowhere near high enough to cause it to happen in order to save on the power bill. They probably never will be.
- sparker72678 6y ago
  I think our best hope for this working out is from the (very slowly) growing view of light pollution as the actual _pollution_ that it is. I would absolutely love this, but I still find it hard to imagine this changing in any significant way in the next 25 years.

kleton 6y ago

Would need $20/KWh battery storage to be competitive with nuclear for baseload according to https://www.cell.com/joule/fulltext/S2542-4351(19)30300-9 https://www.cell.com/joule/fulltext/S2542-4351(19)30300-9 At the moment, we're at about $800/KWh.

jxidjhdhdhdhfhf 6y ago
Aren't car battery packs under $100/KWh? Is there some other factor which drives up the price for grid level storage?
- manfredo 6y ago
  The factor that drives up price for grid level storage is scale. Only ~300 GWh worth of batteries is produced globally each year. The world uses 2.5 TWh of electricity each hour. If anyone tries to install battery storage at a significant scale, demand will vastly outstrip supply and drive prices up.
  - deleted 6y ago
    [deleted]
  - jeremysalwen 6y ago
    Assuming there aren't economies of scale. Demand for solar had gone way up in recent decades (e.g. in germany, before it was cheap), and the price subsequently went down.
    - mlyle 6y ago
      It's not clear batteries will do the same. While there's been effort to make batteries less reliant on scarce natural resources and mining, there's no guarantee we really get there. If we don't, price can be expected to go up, not down, with scale. I would bet on price going down slightly with scale, but one can't really tell now what will happen: it might go up a lot, it might go down a lot, or it might stay flat.

andechs 6y ago

Not all battery storage needs to be electrochemical - hydroelectric dams work amazingly as pumped storage batteries (although site specific).

amelius 6y ago
What is the typical efficiency of a charge-discharge cycle?
- vkou 6y ago
  It's relatively high, the problem is that building new dams is an environmental disaster, and existing dams are two orders of magnitude below needed capacity. Also, hydro dams kill a lot of people when they have accidents.
  - chrisco255 6y ago
    Do you have to dam a river to store energy in this way? Can they just build water towers that pull water from underground up into a tank and release it via gravity to generate power when needed?
    - marvin 6y ago
      Not enough energy. Hydropower reservoirs are typically many square kilometers of water surface, depth > 10 meters on average and a height differential on the order of 100 meters or more. Vary parameters according to geography, but it's not something that can be built without using geology for support.
      - chrisco255 6y ago
        Yeah but in this case, the hydropower is being used for power generation, not as a battery supplement for solar/wind, right? Does it need to be so massive to act as a replacement/alternative for Lithium battery banks?

turtlebits 6y ago

People use way too much power for battery storage to be viable. The average household consumes 28.9kwh in a day (in 2017), which is way more than rooftop solar can provide. Maybe when we have smaller houses and don't have a bajillion devices plugged in all the time.

cronix 6y ago
It's amazing how much less of something you use when you don't have basically an endless, cheap supply of it. You tend to conserve a lot more because you know it's finite and will run out if you use too much.
coderintherye 6y ago
The majority of solar comes from Utility scale about 60/40 vs. rooftop solar: https://en.wikipedia.org/wiki/Solar_power_in_the_United_States#Solar_PV_by_type https://en.wikipedia.org/wiki/Solar_power_in_the_United_Stat...
- flgb 6y ago
  Not in Australia, where we have much more roof-top solar (and which is less than half-the-price installed of roof-top in the US)
  - kragen 6y ago
    Interesting! Do you have any idea why it's so much cheaper?
    - dragonwriter 6y ago
      Shipping costs from China, who is the source of key materials?
      - kragen 6y ago
        You might think so, but no. It's the wrong order of magnitude. That could add maybe US$2000 per TEU, which is 21 tonnes of cargo such as solar panels. You can ship a TEU anywhere in the world for US$3000 or less. A 1m² solar panel might weigh 20 kg, so that's roughly 1000 solar pannels, or US$2 per solar panel. That solar panel is about 200 Wp, so this works out to US$0.01 of shipping cost per peak watt. Or less. The solar module itself costs some US$0.18/Wp wholesale (the article cites higher prices, but see http://pvinsights.com/ http://pvinsights.com/ https://www.solarserver.de/pv-modulpreise/ https://www.solarserver.de/pv-modulpreise/ https://www.energytrend.com/solar-price.html https://www.energytrend.com/solar-price.html for more detailed and reliable pricing info), and the whole installation including the panels maybe US$0.50/Wp. So there's no way that an extra US$0.01/Wp could double the cost of the installation. Bump it by 2% maybe. China isn't the source of key materials. There aren't any key materials; the ingredients in PV cells, except for silver, are abundant everywhere. It's the source of the fully manufactured photovoltaic modules, a finished product that you can prop up in the sun and connect to a battery through a diode. If shipping costs were so high relative to the value of the finished product, every country would have its own solar-cell manufacturing plants, the way every country has its own liquid-oxygen plants, and there wouldn't be such a thing as a worldwide concentration of PV manufacturing in China.

jxidjhdhdhdhfhf 6y ago

Might be of interest to you: the think tank Rethinkx is forecasting wind and solar + lithium ion batteries will be cheaper than continuing to run already existing coal and gas power plants by 2030. They believe this will cause the capital invested in other types of power plants to become "stranded". https://youtu.be/6zgwiQ6BoLA https://youtu.be/6zgwiQ6BoLA

pfdietz 6y ago

https://model.energy/ https://model.energy/ Play with the assumptions and find out.