4 ms·

Those are non-intermittent kilowatt hours, though (and the maintenance that does need to happen is known in advance). One energy demand at peak production is sa

Those are non-intermittent kilowatt hours, though (and the maintenance that does need to happen is known in advance). One energy demand at peak production is saturated, intermittent sources become a lot more expensive since storage needs to be provisioned. Some markets are fast approaching this scenario: https://reneweconomy.com.au/california-duck-curve-now-a-canyon-as-grid-load-vanishes-in-the-midday-sun/ https://reneweconomy.com.au/california-duck-curve-now-a-cany...

Scoundreller 3y ago
Wouldn’t solar, as an intermittent source, be well correlated with demand in Georgia? Sun’s out = heavy AC load? Doing any grid 100% solar needs a lot of storage, but there’s gotta be a perfect point that mostly shaves peaks really nicely. (Yeah yeah, it can be cloudy and hot+humid, but still)
- Manuel_D 3y ago
  Demand typically peaks in the evening, around 9pm. This is right as the sun sets, where solar is tapering off. It's not "shaving peaks" about half your electricity consumption (including peak consumption) is going to happen during periods of non-production.
  - ZeroGravitas 3y ago
    And yet their on-peak times in the summer ends at 7pm: > Shift some of your summer energy usage away from the on-peak time periods (2-7 p.m., Monday–Friday, June–September, excluding holidays).
    - Manuel_D 3y ago
      Demand shifting is just a long winded way of saying, "we can't generate enough electricity, you just need to stop using power at certain times of day." And it's easier said than done. Residential demand shifting, and some forms of industry (e.g. arc furnaces) can shift demand. But others cannot: the pumps powering your sewage system needs to work all day around. Same with data centers, and plenty of other industries.
      - nicoburns 3y ago
        Right, but we don't need to shift all demand for it to have a big impact on the amount of storage required. Any demand shifted is energy that doesn't need to be stored.
dv_dt 3y ago
Many smaller intermittent sources with non-correlated outages is better for availability than a single dominant source even with preplanned maintenance intermittency. What is the emergency and disaster planning impact if the nuclear plant goes down in the middle of a summer heatwave?
- Manuel_D 3y ago
  Smaller intermittent sources don't really help since they're still subject to the same weather patterns and earth rotation. Distributing generation across continents would involve massive costs in energy transmission. People like to tout that intermittent sources are more distributed and less centralized. But that's negative facet of renewables, since demand is centralized in population centers, and distributed production means more transmission costs. The same criticism can be applied to any electricity source: What happens wind stops during a heatwave? Or when the sun goes down? You might say nuclear is less reliable, but the reality is nuclear power has the highest capacity factor of all generation sources: https://www.energy.gov/ne/articles/what-generation-capacity#:~:text=The%20Capacity%20Factor&text=Nuclear%20has%20the%20highest%20capacity,and%20solar%20(24.6%25)%20plants https://www.energy.gov/ne/articles/what-generation-capacity#....
  - dv_dt 3y ago
    Instead of proposing cross-continent distribution lines, just build more small regional renewable sources... unlike nuclear, their costs keep going down. Smaller renewable solar and wind sources with battery storage are perfectly fine, and the correlation in heat with sun works to reduce the need for storage capacity. Capacity factor does not address reliability or emergency planning...
    - Manuel_D 3y ago
      > Smaller renewable solar and wind sources with battery storage are perfectly fine, and the correlation in heat with sun works to reduce the need for storage capacity. Again, peak electricity demand does not happen at noon. It happens at around 9pm, when the sun either has set or is about to set. Unfortunately, solar's production does not match demand patterns. > Instead of proposing cross-continent distribution lines, just build more small regional renewable sources... Again, all the renewable sources in the same region are subject to the same weather patterns and and day/night cycles. Sure multiple solar farms gives you redundancy against some sort of mechanical failure that causes one specific solar farm to go down. But the most common failure mode in intermittent sources is cloud cover or lower-than-expected wind speeds. A backup solar plant a mile away isn't going to give you redundancy against weather patterns. This is why a lot of plans for renewable grids are contingent on thousands of miles of HVDC lines to move energy across continents. > Capacity factor does not address reliability or emergency planning... Capacity factor describes the uptime of a power plant. Nuclear power has the highest uptime. The point is it's less likely to go down than all alternatives.
Retric 3y ago
Non-interment kilowatt hours are actually less valuable. Demand dips at night, the weekend, spring and fall etc. So when negotiating power purchase agreements grid operators are pricing most of that production when it’s least valuable. Battery backed solar is becoming really popular with grid operators because you get the upsides of load following without the overhead of mostly idle production. The economics get interesting as more solar comes online, but things are only getting much worse for nuclear and coal. Which is why there is basically nothing in the pipeline for either one.
- Manuel_D 3y ago
  Incorrect, demand peaks right as night starts and the sun goes down. See that peak [1] at 9pm? Battery backed solar is not even remotely feasible. To put this in perspective, the USA alone uses ~11.5 TWh of electricty each day. A battery to last through the night is over 5,000 GWh. 1. https://b698061.smushcdn.com/698061/wp-content/uploads/2023/05/CASIO-duck-curve-circa-2013.jpg?lossy=1&strip=1&webp=1 https://b698061.smushcdn.com/698061/wp-content/uploads/2023/...
  - Retric 3y ago
    There are several battery backed solar power plants in the US already built. Collocated Solar with batteries increases efficiency as DC from solar is used to directly charge batteries without the cost or losses associated with DC>AC>DC you would see if these where separate. LCOE is already below 60$/MWh because you only need batteries for a fraction of total production. https://atb.nrel.gov/electricity/2022/utility-scale_pv-plus-battery https://atb.nrel.gov/electricity/2022/utility-scale_pv-plus-...
    - Manuel_D 3y ago
      Sure, but those battery backed solar plants usually only have 2-4 hours worth of storage. They're not actually producing full output throughout the night. The cost of batteries would skyrocket if countries actually tried to provision 12 hours of battery storage. Because the US alone uses 500 GWh of electricity each hour. This is greater than the global battery production figures in 2022 [1]. 1. https://www.spglobal.com/mobility/en/research-analysis/growth-of-liion-battery-manufacturing-capacity.html https://www.spglobal.com/mobility/en/research-analysis/growt...
bryanlarsen 3y ago
A Tesla megapack holds 3MWh and is warranted for 15years. If you use the entire capacity daily for duck curve shifting and it dies the day after its warranty runs out, (3MWh * 365 * 15), that's 16 TWh. A megapack costs $1.8M, for a cost of 11 cents per kWh. That's cheaper than the fully loaded cost of Vogtle. But of course you don't have store every kWh used. Peak demand in the summer is caused by A/C and corresponds closely with peak solar generation and can be used directly. New solar farms have a cost of about 0.5cents per kWh, but we'll use 1cent per kWh to be generous. So if you use 3/4 of your power directly and shift 1/4 you end up with an average cost of 0.751c + 0.25(11+1) = 2.75 cents. And those costs aren't theoretical. For a concrete example, the 8minute energy Eland project proves 24h battery+solar energy for under 4 cents per kWh.
- Manuel_D 3y ago
  3 MWh is a trivial amount of storage. That's less than 10 seconds of this plant's output. To put this in perspective, the USA uses 11.5 TWh of electricity each day. That's just under 500 GWh per hour. You'd need a lot of megapacks to provision 8 hours of storage. The Eland project you mention has 4 hours of storage, it's not a 24 hour production system. The reality is that renewables are currently only viable to supplement a grid primary backed by a dispatchable source of energy. If you have loads of hydroelectricity, that's fine, but the regions that don't have hydroelectric potential are going to be stuck burning fossil fuels until a massive storage breakthrough is found.
  - bryanlarsen 3y ago
    It's a trivial amount of storage for a trivial amount of money. Do the math, don't hand wave. The Eland project provides 24 hour power with only 4hr of storage. That's the demand curve in action.
    - Manuel_D 3y ago
      > It's a trivial amount of storage for a trivial amount of money. Do the math, don't hand wave. Sure thing! Right now we have an annual battery production rate of 500 GWh globally [1]. If we're going to use global battery production figures, we need to use global electricity consumption, which is about 70 TWh per day [2]. How much storage we'll need varies, depending on the mix of solar and wind. Estimates I can find say 12 hours on the low end, 3 weeks on the high end [3]. So even with the optimistic estimates of 12 hours, that means we'd need 35,000 GWh of storage. This is 70 years of global production at our current rate, for the optimistic storage estimates. And of course we can't dedicate all battery production to grid storage - we need them for electric vehicles, and electrical devices Production of batteries may grow in the future, but then again so will electricity demand as countries develop and transportation becomes more electrified. Furthermore, we're not counting the fact that batteries have limited lifetimes. It depends on depth of discharge, but we're usually looking at 1,500 to 3,000 cycles before they're substantially degraded. As your can see, the scale of battery production and the scale of energy storage required to make intermittent sources variable are totally mismatched. The reality is there is no amount of money that will provision the battery storage required, because if countries across the world start trying to buy terawatt hours of batteries when only 500GWh of batteries are produced then the cost of batteries will skyrocket. Cathode material already > The Eland project provides 24 hour power with only 4hr of storage. That's the demand curve in action. The "demand curve" means Eland doesn't provide 24 hours of power at its rated output. It provides a fraction of its rated power at night and tells customers not to use as much electricity. This may work for some consumers, but not others. The pumps powering your sewage system can't demand shift if you want to flush your toilet at night. The reality is that peak energy demand happens at night [4], when storage isn't producing electricity. Eland can do this demand shift because other producers are picking up the slack. When you read about storage projects you need to be on the lookout for weasel-words like this. Demand curve means they produce a fraction of the rated power output during periods of non-production. If I have a plant that produces 1,000 MW during the date and 100=MW at night, that's technically 24 hours of production. But clearly this is not the same thing as a nuclear plant that produces 1n000 MW at all hours. 1. https://www.spglobal.com/mobility/en/research-analysis/growth-of-liion-battery-manufacturing-capacity.html https://www.spglobal.com/mobility/en/research-analysis/growt... 2. https://www.statista.com/statistics/280704/world-power-consumption/ https://www.statista.com/statistics/280704/world-power-consu... 3. https://pv-magazine-usa.com/2018/03/01/12-hours-energy-storage-80-percent-wind-solar/ https://pv-magazine-usa.com/2018/03/01/12-hours-energy-stora... 4. https://reneweconomy.com.au/california-duck-curve-now-a-canyon-as-grid-load-vanishes-in-the-midday-sun/ https://reneweconomy.com.au/california-duck-curve-now-a-cany...
pfdietz 3y ago
Once cheap intermittent sources have in the moment saturated the market, nuclear cannot charge what it needs to pay off the very large capital cost. Nuclear is then dependent on making that money during brief spikes, but storage and demand dispatch will be flattening those spikes. Nuclear will have nowhere to hide.
- Manuel_D 3y ago
  Once cheap intermittent sources have saturated the market during peak production, further construction of intermittent sources will do nothing to displace the other 50% of demand that will continue to be fulfilled by fossil fuels. And then we either keep burning fossil fuels and wait until a storage breakthrough happens, or we start building non-intermittent sources of decarbonized energy.
  - pfdietz 3y ago
    Or we just raise taxes on the fossil fuels until they stop being burned. This will have to be done anyway (along with CO2 tariffs to isolate countries that refuse to do so.) After that, storage gets rolled out. Nuclear never makes sense, and eventually the existing NPPs go away.
    - Manuel_D 3y ago
      We raise taxes on fossil fuels, and then what? More investment in intermittent sources works until peak production is saturated. But now thanks to fuel taxes, lithium becomes a lot more expensive to mine since the heavy machinery is more expensive to fuel. Taxes on fossil fuels would reduce emissions, mostly by contracting the economy. It doesn't translate into more storage build out, and it certainly doesn't solve the orders-of-magnitude mismatch between the amount of storage available and the amount of storage required to smooth out intermittent sources.
      - Retric 3y ago
        Raw lithium is a small fraction of the cost of battery, using recent costs your looking at ~4% of total battery price from low purity lithium. People focus on it because of the name rather than nickel-cobalt-manganese or whatever the specific chemistry actually used. They also confuse mining costs with manufacturing costs when looking at ultra pure lithium ready for use in batteries but that’s like conflating the cost of 99.999% pure monocrystalline silicon with the cost of silicon in glass. Batteries don’t need much Lithium and the stuff is more abundant than lead, tin, iodine, mercury, etc.

Scoundreller 3y ago

Wouldn’t solar, as an intermittent source, be well correlated with demand in Georgia? Sun’s out = heavy AC load? Doing any grid 100% solar needs a lot of storage, but there’s gotta be a perfect point that mostly shaves peaks really nicely. (Yeah yeah, it can be cloudy and hot+humid, but still)

Manuel_D 3y ago
Demand typically peaks in the evening, around 9pm. This is right as the sun sets, where solar is tapering off. It's not "shaving peaks" about half your electricity consumption (including peak consumption) is going to happen during periods of non-production.
- ZeroGravitas 3y ago
  And yet their on-peak times in the summer ends at 7pm: > Shift some of your summer energy usage away from the on-peak time periods (2-7 p.m., Monday–Friday, June–September, excluding holidays).
  - Manuel_D 3y ago
    Demand shifting is just a long winded way of saying, "we can't generate enough electricity, you just need to stop using power at certain times of day." And it's easier said than done. Residential demand shifting, and some forms of industry (e.g. arc furnaces) can shift demand. But others cannot: the pumps powering your sewage system needs to work all day around. Same with data centers, and plenty of other industries.
    - nicoburns 3y ago
      Right, but we don't need to shift all demand for it to have a big impact on the amount of storage required. Any demand shifted is energy that doesn't need to be stored.

dv_dt 3y ago

Many smaller intermittent sources with non-correlated outages is better for availability than a single dominant source even with preplanned maintenance intermittency. What is the emergency and disaster planning impact if the nuclear plant goes down in the middle of a summer heatwave?

Manuel_D 3y ago
Smaller intermittent sources don't really help since they're still subject to the same weather patterns and earth rotation. Distributing generation across continents would involve massive costs in energy transmission. People like to tout that intermittent sources are more distributed and less centralized. But that's negative facet of renewables, since demand is centralized in population centers, and distributed production means more transmission costs. The same criticism can be applied to any electricity source: What happens wind stops during a heatwave? Or when the sun goes down? You might say nuclear is less reliable, but the reality is nuclear power has the highest capacity factor of all generation sources: https://www.energy.gov/ne/articles/what-generation-capacity#:~:text=The%20Capacity%20Factor&text=Nuclear%20has%20the%20highest%20capacity,and%20solar%20(24.6%25)%20plants https://www.energy.gov/ne/articles/what-generation-capacity#....
- dv_dt 3y ago
  Instead of proposing cross-continent distribution lines, just build more small regional renewable sources... unlike nuclear, their costs keep going down. Smaller renewable solar and wind sources with battery storage are perfectly fine, and the correlation in heat with sun works to reduce the need for storage capacity. Capacity factor does not address reliability or emergency planning...
  - Manuel_D 3y ago
    > Smaller renewable solar and wind sources with battery storage are perfectly fine, and the correlation in heat with sun works to reduce the need for storage capacity. Again, peak electricity demand does not happen at noon. It happens at around 9pm, when the sun either has set or is about to set. Unfortunately, solar's production does not match demand patterns. > Instead of proposing cross-continent distribution lines, just build more small regional renewable sources... Again, all the renewable sources in the same region are subject to the same weather patterns and and day/night cycles. Sure multiple solar farms gives you redundancy against some sort of mechanical failure that causes one specific solar farm to go down. But the most common failure mode in intermittent sources is cloud cover or lower-than-expected wind speeds. A backup solar plant a mile away isn't going to give you redundancy against weather patterns. This is why a lot of plans for renewable grids are contingent on thousands of miles of HVDC lines to move energy across continents. > Capacity factor does not address reliability or emergency planning... Capacity factor describes the uptime of a power plant. Nuclear power has the highest uptime. The point is it's less likely to go down than all alternatives.

Retric 3y ago

Non-interment kilowatt hours are actually less valuable. Demand dips at night, the weekend, spring and fall etc. So when negotiating power purchase agreements grid operators are pricing most of that production when it’s least valuable. Battery backed solar is becoming really popular with grid operators because you get the upsides of load following without the overhead of mostly idle production. The economics get interesting as more solar comes online, but things are only getting much worse for nuclear and coal. Which is why there is basically nothing in the pipeline for either one.

Manuel_D 3y ago
Incorrect, demand peaks right as night starts and the sun goes down. See that peak [1] at 9pm? Battery backed solar is not even remotely feasible. To put this in perspective, the USA alone uses ~11.5 TWh of electricty each day. A battery to last through the night is over 5,000 GWh. 1. https://b698061.smushcdn.com/698061/wp-content/uploads/2023/05/CASIO-duck-curve-circa-2013.jpg?lossy=1&strip=1&webp=1 https://b698061.smushcdn.com/698061/wp-content/uploads/2023/...
- Retric 3y ago
  There are several battery backed solar power plants in the US already built. Collocated Solar with batteries increases efficiency as DC from solar is used to directly charge batteries without the cost or losses associated with DC>AC>DC you would see if these where separate. LCOE is already below 60$/MWh because you only need batteries for a fraction of total production. https://atb.nrel.gov/electricity/2022/utility-scale_pv-plus-battery https://atb.nrel.gov/electricity/2022/utility-scale_pv-plus-...
  - Manuel_D 3y ago
    Sure, but those battery backed solar plants usually only have 2-4 hours worth of storage. They're not actually producing full output throughout the night. The cost of batteries would skyrocket if countries actually tried to provision 12 hours of battery storage. Because the US alone uses 500 GWh of electricity each hour. This is greater than the global battery production figures in 2022 [1]. 1. https://www.spglobal.com/mobility/en/research-analysis/growth-of-liion-battery-manufacturing-capacity.html https://www.spglobal.com/mobility/en/research-analysis/growt...

bryanlarsen 3y ago

A Tesla megapack holds 3MWh and is warranted for 15years. If you use the entire capacity daily for duck curve shifting and it dies the day after its warranty runs out, (3MWh * 365 * 15), that's 16 TWh. A megapack costs $1.8M, for a cost of 11 cents per kWh. That's cheaper than the fully loaded cost of Vogtle. But of course you don't have store every kWh used. Peak demand in the summer is caused by A/C and corresponds closely with peak solar generation and can be used directly. New solar farms have a cost of about 0.5cents per kWh, but we'll use 1cent per kWh to be generous. So if you use 3/4 of your power directly and shift 1/4 you end up with an average cost of 0.751c + 0.25(11+1) = 2.75 cents. And those costs aren't theoretical. For a concrete example, the 8minute energy Eland project proves 24h battery+solar energy for under 4 cents per kWh.

Manuel_D 3y ago
3 MWh is a trivial amount of storage. That's less than 10 seconds of this plant's output. To put this in perspective, the USA uses 11.5 TWh of electricity each day. That's just under 500 GWh per hour. You'd need a lot of megapacks to provision 8 hours of storage. The Eland project you mention has 4 hours of storage, it's not a 24 hour production system. The reality is that renewables are currently only viable to supplement a grid primary backed by a dispatchable source of energy. If you have loads of hydroelectricity, that's fine, but the regions that don't have hydroelectric potential are going to be stuck burning fossil fuels until a massive storage breakthrough is found.
- bryanlarsen 3y ago
  It's a trivial amount of storage for a trivial amount of money. Do the math, don't hand wave. The Eland project provides 24 hour power with only 4hr of storage. That's the demand curve in action.
  - Manuel_D 3y ago
    > It's a trivial amount of storage for a trivial amount of money. Do the math, don't hand wave. Sure thing! Right now we have an annual battery production rate of 500 GWh globally [1]. If we're going to use global battery production figures, we need to use global electricity consumption, which is about 70 TWh per day [2]. How much storage we'll need varies, depending on the mix of solar and wind. Estimates I can find say 12 hours on the low end, 3 weeks on the high end [3]. So even with the optimistic estimates of 12 hours, that means we'd need 35,000 GWh of storage. This is 70 years of global production at our current rate, for the optimistic storage estimates. And of course we can't dedicate all battery production to grid storage - we need them for electric vehicles, and electrical devices Production of batteries may grow in the future, but then again so will electricity demand as countries develop and transportation becomes more electrified. Furthermore, we're not counting the fact that batteries have limited lifetimes. It depends on depth of discharge, but we're usually looking at 1,500 to 3,000 cycles before they're substantially degraded. As your can see, the scale of battery production and the scale of energy storage required to make intermittent sources variable are totally mismatched. The reality is there is no amount of money that will provision the battery storage required, because if countries across the world start trying to buy terawatt hours of batteries when only 500GWh of batteries are produced then the cost of batteries will skyrocket. Cathode material already > The Eland project provides 24 hour power with only 4hr of storage. That's the demand curve in action. The "demand curve" means Eland doesn't provide 24 hours of power at its rated output. It provides a fraction of its rated power at night and tells customers not to use as much electricity. This may work for some consumers, but not others. The pumps powering your sewage system can't demand shift if you want to flush your toilet at night. The reality is that peak energy demand happens at night [4], when storage isn't producing electricity. Eland can do this demand shift because other producers are picking up the slack. When you read about storage projects you need to be on the lookout for weasel-words like this. Demand curve means they produce a fraction of the rated power output during periods of non-production. If I have a plant that produces 1,000 MW during the date and 100=MW at night, that's technically 24 hours of production. But clearly this is not the same thing as a nuclear plant that produces 1n000 MW at all hours. 1. https://www.spglobal.com/mobility/en/research-analysis/growth-of-liion-battery-manufacturing-capacity.html https://www.spglobal.com/mobility/en/research-analysis/growt... 2. https://www.statista.com/statistics/280704/world-power-consumption/ https://www.statista.com/statistics/280704/world-power-consu... 3. https://pv-magazine-usa.com/2018/03/01/12-hours-energy-storage-80-percent-wind-solar/ https://pv-magazine-usa.com/2018/03/01/12-hours-energy-stora... 4. https://reneweconomy.com.au/california-duck-curve-now-a-canyon-as-grid-load-vanishes-in-the-midday-sun/ https://reneweconomy.com.au/california-duck-curve-now-a-cany...

pfdietz 3y ago

Once cheap intermittent sources have in the moment saturated the market, nuclear cannot charge what it needs to pay off the very large capital cost. Nuclear is then dependent on making that money during brief spikes, but storage and demand dispatch will be flattening those spikes. Nuclear will have nowhere to hide.

Manuel_D 3y ago
Once cheap intermittent sources have saturated the market during peak production, further construction of intermittent sources will do nothing to displace the other 50% of demand that will continue to be fulfilled by fossil fuels. And then we either keep burning fossil fuels and wait until a storage breakthrough happens, or we start building non-intermittent sources of decarbonized energy.
- pfdietz 3y ago
  Or we just raise taxes on the fossil fuels until they stop being burned. This will have to be done anyway (along with CO2 tariffs to isolate countries that refuse to do so.) After that, storage gets rolled out. Nuclear never makes sense, and eventually the existing NPPs go away.
  - Manuel_D 3y ago
    We raise taxes on fossil fuels, and then what? More investment in intermittent sources works until peak production is saturated. But now thanks to fuel taxes, lithium becomes a lot more expensive to mine since the heavy machinery is more expensive to fuel. Taxes on fossil fuels would reduce emissions, mostly by contracting the economy. It doesn't translate into more storage build out, and it certainly doesn't solve the orders-of-magnitude mismatch between the amount of storage available and the amount of storage required to smooth out intermittent sources.
    - Retric 3y ago
      Raw lithium is a small fraction of the cost of battery, using recent costs your looking at ~4% of total battery price from low purity lithium. People focus on it because of the name rather than nickel-cobalt-manganese or whatever the specific chemistry actually used. They also confuse mining costs with manufacturing costs when looking at ultra pure lithium ready for use in batteries but that’s like conflating the cost of 99.999% pure monocrystalline silicon with the cost of silicon in glass. Batteries don’t need much Lithium and the stuff is more abundant than lead, tin, iodine, mercury, etc.