5 ms·

This is nameplate capacity: the power a generator can deliver, full on, under ideal conditions. Solar and wind always look great when measured in nameplate capa

This is nameplate capacity: the power a generator can deliver, full on, under ideal conditions. Solar and wind always look great when measured in nameplate capacity, which is why this is done. If you want to know how much electricity they will generate, you have to multiply by the capacity factor. Nuclear, for instance has a capacity factor of 0.9 in the US: it delivers 90% of its nameplate capacity in a given year. Solar ranges between 0.08 and 0.15.

why_only_15 3y ago
In the US, PV solar capacity factor is about 0.24 (partly because lots of people live near very sunny regions like California and Texas). The National Renewable Energy Laboratory claims that in some parts of the US utility-scale solar capacity factors are 0.33 [0]. Wind is about 0.36, Hydro also 0.36, Nuclear about 0.93 [1]. If you apply these capacity factors to the nameplate capacities (ignoring batteries), you get 58.5% solar, 19.7% wind, 15.1% natural gas, and 6.6% nuclear. [0]: https://atb.nrel.gov/electricity/2021/utility-scale_pv https://atb.nrel.gov/electricity/2021/utility-scale_pv [1]: https://www.eia.gov/electricity/monthly/epm_table_grapher.php?t=epmt_6_07_b https://www.eia.gov/electricity/monthly/epm_table_grapher.ph...
- Retric 3y ago
  US nuclear averages below 0.9, individual plants can break 0.93 for a single year, but long term maintenance and refueling cycles lower the average. Ex: 95.73% (2017) 80.25% (lifetime) https://en.wikipedia.org/wiki/Beaver_Valley_Nuclear_Power_Station https://en.wikipedia.org/wiki/Beaver_Valley_Nuclear_Power_St... 94.43% (2017) 75.20% (lifetime) https://en.wikipedia.org/wiki/Brunswick_Nuclear_Generating_Station https://en.wikipedia.org/wiki/Brunswick_Nuclear_Generating_S... 96.04% (2017) 78.07% (lifetime) https://en.wikipedia.org/wiki/Browns_Ferry_Nuclear_Plant https://en.wikipedia.org/wiki/Browns_Ferry_Nuclear_Plant So you can cherry pick a few numbers from the best years, but the lifetime averages tell a different story.
  - foota 3y ago
    Is a 15% difference that much of a different story?
    - hef19898 3y ago
      Look at your paycheck, and imagine the number is 15% lower. Should answer the question.
      - deleted 3y ago
        [deleted]
      - blackoil 3y ago
        If alternate pay is 90% lower, not big of a difference. i.e. If I lose job, I would prefer new one to pay 85% than 10%.
      - foota 3y ago
        It does. And no, it's not that significant. I'm not a nuclear fanboy (well, I wish I made sense since I like the idea of free energy, but renewables are just as good), but I think it's important to make accurate arguments.
        hef19898 3y ago
        An accurate argument would include the financial aspects of +/- 15% in generated output and the impact that has on grid capacity....
        deleted 3y ago
        [deleted]
        deleted 3y ago
        [deleted]
        foota 3y ago
        With such a small difference, the burden of proof in this case is probably on the person arguing that it is a big difference, since you'd generally expect a roughly linear relationship between these. In fact, I think I'd suspect that downtime is less relevant for nuclear, since I believe most of it will be schedulable, as opposed to renewables where downtime is random and based on conditions. Since it's schedulable, it could be done in the off season, or different plants could be planned to be out at difference periods.
- Maakuth 3y ago
  Of course those capacity factors hide one important bit, the dispatchability. While the capacity factor is the same in this list for wind and hydro, the wind and solar generation are naturally capped by nature. When demand exceeds the natural availability of these, you need to dispatch some extra generation. Hydro and natural gas are well suited for this, coal can do it even if dirtily. Nuclear generation could be made dispatchable, but due to the essentially zero marginal cost of running it all the time instead of limiting generation, it seldom is used in this fashion. Electricity demand could be elastic too, but there's a limit to that. It's not always feasible to limit or shut down industrial processes for the few hours of expensive power. And home consumers are loath to not use their stoves when they want. There's potential in elastic demand though.
  - hef19898 3y ago
    Take a close look at the title again, second word after "solar", you have to pass by "and" to get there.
    - Maakuth 3y ago
      I guess I earned the snark for not mentioning the batteries. Weirdly the news item doesn't tell what sort of energy storage capacity these battery installation have, only the peak power output of 14.3 GW for this year's addition. While that is certainly a gigantic addition no matter what the energy capacity of these battery installations is going to be, running the whole grid on batteries over the periods of low renewable generation is going to require still orders of magnitude more batteries. I suppose there's enough lithium in the ground for this, but elastic demand and dispatchable generation are probably going to be part of the equation for economical reasons.
      - randunel 3y ago
        Plenty of batteries in the US are built out of water. They pump the water up during the day and it generates electricity at night. No lithium involved. > Pumped storage is by far the largest-capacity form of grid energy storage available, and, as of 2020, the United States Department of Energy Global Energy Storage Database reports that PSH accounts for around 95% of all active tracked storage installations worldwide, with a total installed throughput capacity of over 181 GW, of which about 29 GW are in the United States, and a total installed storage capacity of over 1.6 TWh, of which about 250 GWh are in the United States. I recently visited this one https://en.m.wikipedia.org/wiki/Gianelli_Power_Plant https://en.m.wikipedia.org/wiki/Gianelli_Power_Plant
- ianai 3y ago
  This discussion makes me realize we could have a 100% renewable energy grid and discussion will still be pushed with the same old “arguments” against renewable being feasible. Ridiculous.
- dfc 3y ago
  I do not understand your math. How did you go from .36 for wind, apply it to nameplate capacity and get 15.1%? And percent of what? I thought applying the capacity factor to nameplate would result in some measure of energy produced, not a percentage.
epistasis 3y ago
Yes, correcting for capacity factor is essential if you want to compare potential energy generated over a year (which is perhaps not the most common use of these numbers). Gas generators are typically less than 50% capacity factor, and batteries should have course have a 0% capacity factor for comparison of energy created over a year However, your capacity factors for solar are far too low, average CF is above 20%. There are roughly as many installs with CF>30% as there are with CF<15%.: https://emp.lbl.gov/pv-capacity-factors https://emp.lbl.gov/pv-capacity-factors Also omitted from this view is the cost per MWh delivered to the grid. A great overview of the current state of the technology, including costs ($40/MWh), is here: https://emp.lbl.gov/sites/default/files/utility_scale_solar_2023_edition_slides.pdf https://emp.lbl.gov/sites/default/files/utility_scale_solar_... There's also a great overview of the state of batters here, where conservative estimates of lifetime cost of stored energy results in about $88/MWh: https://www.nrel.gov/docs/fy23osti/85332.pdf https://www.nrel.gov/docs/fy23osti/85332.pdf For the new nuclear cost, it's actually really hard to dig up, because it's a bit too embarrassing to the industry. But by taking the factors from this slide deck: https://liftoff.energy.gov/advanced-nuclear/ https://liftoff.energy.gov/advanced-nuclear/ And scaling the slide 14 numbers for $9k/kW overnight cost to the real cost of $15/kW at Vogtle, and we get nuclear costs north of $180/MWh for nuclear when including the new subsidies from Biden's IRA legislation (north of $200/MWh unsubsidized).
cwal37 3y ago
That’s not why it is done, it’s because this is reporting in capacity and that is the physical capacity being installed. That phrasing makes it sound nefarious, then you end with a fairly low solar range (which varies substantially and exceeds that in sunnier parts of the US). Bit of an odd take. You could say the same, or lower, of capacity factors on peaking oil or gas plants in some areas that run for only a couple percent of the year. Nameplate and utilization are just different things. Maybe worth noting that despite lower capacity factors and despite it being mid-winter, Texas (ERCOT) keeps setting solar output records because they’re installing so much nameplate[1]. It’s not like it does nothing. [1] https://www.gridstatus.io/records/ercot?record=Maximum%20Solar https://www.gridstatus.io/records/ercot?record=Maximum%20Sol...
- TheDudeMan 3y ago
  Why report on capacity instead of energy? Why would capacity matter at all?
  - icehawk 3y ago
    Because energy generated is an after the fact number in any sort of power generation, and doesn't help with any sort of prediction.
    - blackoil 3y ago
      Considering nameplate capacity without capacity factor would be bad a prediction?? If I need 1GW of extra energy getting 1GW of solar would be a bad bet. Same if I am calculating the pollution generated next year.
      - hef19898 3y ago
        Yes, because load factor are long time averages while electricity generation and consumption are almost real time. Kind of like 4D checkers or something.
  - hef19898 3y ago
Retric 3y ago
Your range is wildly off for PV systems, concentrating solar thermal can be that low but it’s been abandoned for good reason. Utility scale PV solar in the US averages 0.246 with several solar farms in the US having over 0.32 capacity factors. Ex: 0.328 from 2017 - 2019 https://en.wikipedia.org/wiki/Solar_Star https://en.wikipedia.org/wiki/Solar_Star While a nearby PV farm is only 0.275 (average 2015-2018) https://en.wikipedia.org/wiki/Desert_Sunlight_Solar_Farm https://en.wikipedia.org/wiki/Desert_Sunlight_Solar_Farm and another in the middle: 29.7%(average 2015–2017, MS1) https://en.wikipedia.org/wiki/Mount_Signal_Solar https://en.wikipedia.org/wiki/Mount_Signal_Solar Curtailment depends on the specific power purchase agreements so there’s some variability independent of the underlying technology. The discrepancy around PV solar is largely the degree of tracking and location. Fixed panels have the same maximum, but even 1 axis tracking significantly extends how long a panel is producing the maximum power. 2 axis tracking allows even better capacity factor assuming nothing breaks, but at higher cost per kWh. PS: Of note low capacity factor Solar installs are generally far smaller. It’s viable to install a little solar in Maine, but not at the same scale. https://spectrumlocalnews.com/me/maine/news/2022/11/17/construction-begins-on-maine-s-largest-solar-farm https://spectrumlocalnews.com/me/maine/news/2022/11/17/const...
Evidlo 3y ago
Why does nuclear not deliver closer to its ideal power output? Are nuclear plants really down 10% of the time?
- jeffbee 3y ago
  Over their lifecycle they are down more like 20-25%.
  - doikor 3y ago
    Only if the operator is criminally incompetent. 90%+ capacity factor/uptime is pretty much standard and the better ones reach ~95% For example TVO in Finland has 93% to 97% depending on the reactor since the early 1990s. Fortum has very similar numbers for their reactors.
    - jeffbee 3y ago
      This is the definition of cherry-picking data points.
      - doikor 3y ago
        I would say cherry-picking data points is better then providing 0 data points. edit: Basically competent operators hit ~90%. US is around 93%. Sweden 84% Switzerland 90% France would hit that if they could run their plants at 100% when they are on but they run theirs in load following mode due to having so many of them. So they run at around 80%. World average is 83%. https://world-nuclear.org/getmedia/891c0cd8-2beb-4acf-bb4b-552da1696695/world-nuclear-performance-report-2021.pdf.aspx https://world-nuclear.org/getmedia/891c0cd8-2beb-4acf-bb4b-5... And yes I know best the numbers about the market I live in because I live here and this stuff effects the price I have to pay for electricity.
        asadotzler 3y ago
        If the world average is 83% and his claim included 80%, he wasn't as far off as you made him out to be with the criminal negligence business, was he?
hef19898 3y ago
Somehow, that is the latest pro-niclear / anti-renewables talking point. Not tgat people in field learn the principle of load factor in one of the first days of 101 lectures on the subject... It least it is an evolution up from "solar isn't working at night" and similar deep and hot takes on the subject.
- samatman 3y ago
  Pro-nuclear doesn't make one anti-renewables. They're complementary technologies, the rivalry is entirely one-sided. Not to mention incredibly aggravating to those of us who would like power to be reliable, with no emissions.
  - asadotzler 3y ago
    The arguments against renewables from your side since at least the '70s when I came across them first, have been persistent and loud, for half a century! You're gonna just pretend that never happened, walk away from it. The parent mentioned the "duh, sun don't shine at night" line because that's some shit your side was for real pushing, for fucking decades. You don't get to sidestep half a lifetime of that garbage and claim some high ground now.
    - samatman 3y ago
      I'm not on whatever side you're having this imaginary argument with. But keep yelling at a cloud if it brings you pleasure.
audunw 3y ago
Keep in mind that looking at the capacity factor for nuclear vs solar/wind can be misleading as well if you don't take into account even more factors. Renewables are composed of a wide mix of thousands of power plants. And these days the construction of renewables goes along with construction of energy storage and grid upgrades (even taking into account those costs, renewables are now competitive). So any failures/downtimes is smoothed out over both time and space. That ~10% of the time that nuclear is down, you get 100s of MWs going down in a single region. France recently had several nuclear power plants go down at the same time, making them dependent on imports for a long stretch of time. In terms of energy I think it's worth looking at the total net energy added. The largest rate that nuclear ever grew was around ~200TWh for some years in the 80s. Solar grew by ~300TWh from 2021 to 2022. Wind grew by ~200TWh. And the growth rate is still increasing exponentially. For reference the world population grew from ~5 to ~8billion from the 80s until now, if you want to take that into account when comparing the growth rates. I don't think there can be any doubt anymore that renewables will completely dominate the energy production in the future.
weberer 3y ago
Here in Finland, the national power grid operator provides a live graph of how much that each source is outputting. Its kind of funny how solar produces almost no energy during the winter this far north. I'm very happy that we have that new 1,600 MW nuclear plant, so we no longer have to get that energy from coal. https://www.fingrid.fi/en/electricity-market/power-system/ https://www.fingrid.fi/en/electricity-market/power-system/
- megaman821 3y ago
  People want a one-size-fits-all solution, nuclear makes the most sense for the high northern latitudes. Depending on the geography; wind, geothermal and hydro are viable too. Now if you are talking about Egypt, building nuclear over solar/batteries makes absolutely no sense.
  - weberer 3y ago
    Yeah, I just don't like how people here are providing a false dichotomy of "renewables vs nuclear" instead of "renewables+nuclear vs fossil fuels". We should put solar panels on every rooftop so we're not throwing away that free* energy, while having nuclear plants as baseload power to smooth out the duck curve. Polar regions need to slide the scale more toward nuclear, while the equatorial regions can go mostly solar. *free as in beer
    - asadotzler 3y ago
      The main reason for me that your scenario isn't ideal is that if we can pull it off, renewables remove significant risk compared to nuclear. When football field of batteries goes up in smoke, some battery money is lost. When a Fukushima happens, an economy can be lost, and a nontrivial number of lives. Thousands or tens of thousands of lives, hundreds of billions or trillions in damages, nah, I'd like to opt out and instead do the extra work to make renewable and safer sources happen. That's how I vote. If you live above the arctic circle you'll likely vote differently and hopefully your next meltdown doesn't reach my shores.
enslavedrobot 3y ago
The LCOE of nuclear is very sensitive to its capacity factor. Nuclear costs are set to skyrocket because for a larger and larger part of the day they will not be profitable as renewables undercut the price of power. With a lower and lower capacity factor, new nuclear plants will never pay for themselves. https://youtu.be/udJJ7n_Ryjg?si=m-F4DNn5MpNvycPA https://youtu.be/udJJ7n_Ryjg?si=m-F4DNn5MpNvycPA

why_only_15 3y ago

In the US, PV solar capacity factor is about 0.24 (partly because lots of people live near very sunny regions like California and Texas). The National Renewable Energy Laboratory claims that in some parts of the US utility-scale solar capacity factors are 0.33 [0]. Wind is about 0.36, Hydro also 0.36, Nuclear about 0.93 [1]. If you apply these capacity factors to the nameplate capacities (ignoring batteries), you get 58.5% solar, 19.7% wind, 15.1% natural gas, and 6.6% nuclear. [0]: https://atb.nrel.gov/electricity/2021/utility-scale_pv https://atb.nrel.gov/electricity/2021/utility-scale_pv [1]: https://www.eia.gov/electricity/monthly/epm_table_grapher.php?t=epmt_6_07_b https://www.eia.gov/electricity/monthly/epm_table_grapher.ph...

Retric 3y ago
US nuclear averages below 0.9, individual plants can break 0.93 for a single year, but long term maintenance and refueling cycles lower the average. Ex: 95.73% (2017) 80.25% (lifetime) https://en.wikipedia.org/wiki/Beaver_Valley_Nuclear_Power_Station https://en.wikipedia.org/wiki/Beaver_Valley_Nuclear_Power_St... 94.43% (2017) 75.20% (lifetime) https://en.wikipedia.org/wiki/Brunswick_Nuclear_Generating_Station https://en.wikipedia.org/wiki/Brunswick_Nuclear_Generating_S... 96.04% (2017) 78.07% (lifetime) https://en.wikipedia.org/wiki/Browns_Ferry_Nuclear_Plant https://en.wikipedia.org/wiki/Browns_Ferry_Nuclear_Plant So you can cherry pick a few numbers from the best years, but the lifetime averages tell a different story.
- foota 3y ago
  Is a 15% difference that much of a different story?
  - hef19898 3y ago
    Look at your paycheck, and imagine the number is 15% lower. Should answer the question.
    - deleted 3y ago
      [deleted]
    - blackoil 3y ago
      If alternate pay is 90% lower, not big of a difference. i.e. If I lose job, I would prefer new one to pay 85% than 10%.
    - foota 3y ago
      It does. And no, it's not that significant. I'm not a nuclear fanboy (well, I wish I made sense since I like the idea of free energy, but renewables are just as good), but I think it's important to make accurate arguments.
      - hef19898 3y ago
        An accurate argument would include the financial aspects of +/- 15% in generated output and the impact that has on grid capacity....
        deleted 3y ago
        [deleted]
        deleted 3y ago
        [deleted]
        foota 3y ago
        With such a small difference, the burden of proof in this case is probably on the person arguing that it is a big difference, since you'd generally expect a roughly linear relationship between these. In fact, I think I'd suspect that downtime is less relevant for nuclear, since I believe most of it will be schedulable, as opposed to renewables where downtime is random and based on conditions. Since it's schedulable, it could be done in the off season, or different plants could be planned to be out at difference periods.
Maakuth 3y ago
Of course those capacity factors hide one important bit, the dispatchability. While the capacity factor is the same in this list for wind and hydro, the wind and solar generation are naturally capped by nature. When demand exceeds the natural availability of these, you need to dispatch some extra generation. Hydro and natural gas are well suited for this, coal can do it even if dirtily. Nuclear generation could be made dispatchable, but due to the essentially zero marginal cost of running it all the time instead of limiting generation, it seldom is used in this fashion. Electricity demand could be elastic too, but there's a limit to that. It's not always feasible to limit or shut down industrial processes for the few hours of expensive power. And home consumers are loath to not use their stoves when they want. There's potential in elastic demand though.
- hef19898 3y ago
  Take a close look at the title again, second word after "solar", you have to pass by "and" to get there.
  - Maakuth 3y ago
    I guess I earned the snark for not mentioning the batteries. Weirdly the news item doesn't tell what sort of energy storage capacity these battery installation have, only the peak power output of 14.3 GW for this year's addition. While that is certainly a gigantic addition no matter what the energy capacity of these battery installations is going to be, running the whole grid on batteries over the periods of low renewable generation is going to require still orders of magnitude more batteries. I suppose there's enough lithium in the ground for this, but elastic demand and dispatchable generation are probably going to be part of the equation for economical reasons.
    - randunel 3y ago
      Plenty of batteries in the US are built out of water. They pump the water up during the day and it generates electricity at night. No lithium involved. > Pumped storage is by far the largest-capacity form of grid energy storage available, and, as of 2020, the United States Department of Energy Global Energy Storage Database reports that PSH accounts for around 95% of all active tracked storage installations worldwide, with a total installed throughput capacity of over 181 GW, of which about 29 GW are in the United States, and a total installed storage capacity of over 1.6 TWh, of which about 250 GWh are in the United States. I recently visited this one https://en.m.wikipedia.org/wiki/Gianelli_Power_Plant https://en.m.wikipedia.org/wiki/Gianelli_Power_Plant
ianai 3y ago
This discussion makes me realize we could have a 100% renewable energy grid and discussion will still be pushed with the same old “arguments” against renewable being feasible. Ridiculous.
dfc 3y ago
I do not understand your math. How did you go from .36 for wind, apply it to nameplate capacity and get 15.1%? And percent of what? I thought applying the capacity factor to nameplate would result in some measure of energy produced, not a percentage.

epistasis 3y ago

Yes, correcting for capacity factor is essential if you want to compare potential energy generated over a year (which is perhaps not the most common use of these numbers). Gas generators are typically less than 50% capacity factor, and batteries should have course have a 0% capacity factor for comparison of energy created over a year However, your capacity factors for solar are far too low, average CF is above 20%. There are roughly as many installs with CF>30% as there are with CF<15%.: https://emp.lbl.gov/pv-capacity-factors https://emp.lbl.gov/pv-capacity-factors Also omitted from this view is the cost per MWh delivered to the grid. A great overview of the current state of the technology, including costs ($40/MWh), is here: https://emp.lbl.gov/sites/default/files/utility_scale_solar_2023_edition_slides.pdf https://emp.lbl.gov/sites/default/files/utility_scale_solar_... There's also a great overview of the state of batters here, where conservative estimates of lifetime cost of stored energy results in about $88/MWh: https://www.nrel.gov/docs/fy23osti/85332.pdf https://www.nrel.gov/docs/fy23osti/85332.pdf For the new nuclear cost, it's actually really hard to dig up, because it's a bit too embarrassing to the industry. But by taking the factors from this slide deck: https://liftoff.energy.gov/advanced-nuclear/ https://liftoff.energy.gov/advanced-nuclear/ And scaling the slide 14 numbers for $9k/kW overnight cost to the real cost of $15/kW at Vogtle, and we get nuclear costs north of $180/MWh for nuclear when including the new subsidies from Biden's IRA legislation (north of $200/MWh unsubsidized).

cwal37 3y ago

That’s not why it is done, it’s because this is reporting in capacity and that is the physical capacity being installed. That phrasing makes it sound nefarious, then you end with a fairly low solar range (which varies substantially and exceeds that in sunnier parts of the US). Bit of an odd take. You could say the same, or lower, of capacity factors on peaking oil or gas plants in some areas that run for only a couple percent of the year. Nameplate and utilization are just different things. Maybe worth noting that despite lower capacity factors and despite it being mid-winter, Texas (ERCOT) keeps setting solar output records because they’re installing so much nameplate[1]. It’s not like it does nothing. [1] https://www.gridstatus.io/records/ercot?record=Maximum%20Solar https://www.gridstatus.io/records/ercot?record=Maximum%20Sol...

TheDudeMan 3y ago
Why report on capacity instead of energy? Why would capacity matter at all?
- icehawk 3y ago
  Because energy generated is an after the fact number in any sort of power generation, and doesn't help with any sort of prediction.
  - blackoil 3y ago
    Considering nameplate capacity without capacity factor would be bad a prediction?? If I need 1GW of extra energy getting 1GW of solar would be a bad bet. Same if I am calculating the pollution generated next year.
    - hef19898 3y ago
      Yes, because load factor are long time averages while electricity generation and consumption are almost real time. Kind of like 4D checkers or something.
- hef19898 3y ago

Retric 3y ago

Your range is wildly off for PV systems, concentrating solar thermal can be that low but it’s been abandoned for good reason. Utility scale PV solar in the US averages 0.246 with several solar farms in the US having over 0.32 capacity factors. Ex: 0.328 from 2017 - 2019 https://en.wikipedia.org/wiki/Solar_Star https://en.wikipedia.org/wiki/Solar_Star While a nearby PV farm is only 0.275 (average 2015-2018) https://en.wikipedia.org/wiki/Desert_Sunlight_Solar_Farm https://en.wikipedia.org/wiki/Desert_Sunlight_Solar_Farm and another in the middle: 29.7%(average 2015–2017, MS1) https://en.wikipedia.org/wiki/Mount_Signal_Solar https://en.wikipedia.org/wiki/Mount_Signal_Solar Curtailment depends on the specific power purchase agreements so there’s some variability independent of the underlying technology. The discrepancy around PV solar is largely the degree of tracking and location. Fixed panels have the same maximum, but even 1 axis tracking significantly extends how long a panel is producing the maximum power. 2 axis tracking allows even better capacity factor assuming nothing breaks, but at higher cost per kWh. PS: Of note low capacity factor Solar installs are generally far smaller. It’s viable to install a little solar in Maine, but not at the same scale. https://spectrumlocalnews.com/me/maine/news/2022/11/17/construction-begins-on-maine-s-largest-solar-farm https://spectrumlocalnews.com/me/maine/news/2022/11/17/const...

Evidlo 3y ago

Why does nuclear not deliver closer to its ideal power output? Are nuclear plants really down 10% of the time?

jeffbee 3y ago
Over their lifecycle they are down more like 20-25%.
- doikor 3y ago
  Only if the operator is criminally incompetent. 90%+ capacity factor/uptime is pretty much standard and the better ones reach ~95% For example TVO in Finland has 93% to 97% depending on the reactor since the early 1990s. Fortum has very similar numbers for their reactors.
  - jeffbee 3y ago
    This is the definition of cherry-picking data points.
    - doikor 3y ago
      I would say cherry-picking data points is better then providing 0 data points. edit: Basically competent operators hit ~90%. US is around 93%. Sweden 84% Switzerland 90% France would hit that if they could run their plants at 100% when they are on but they run theirs in load following mode due to having so many of them. So they run at around 80%. World average is 83%. https://world-nuclear.org/getmedia/891c0cd8-2beb-4acf-bb4b-552da1696695/world-nuclear-performance-report-2021.pdf.aspx https://world-nuclear.org/getmedia/891c0cd8-2beb-4acf-bb4b-5... And yes I know best the numbers about the market I live in because I live here and this stuff effects the price I have to pay for electricity.
      - asadotzler 3y ago
        If the world average is 83% and his claim included 80%, he wasn't as far off as you made him out to be with the criminal negligence business, was he?

hef19898 3y ago

Somehow, that is the latest pro-niclear / anti-renewables talking point. Not tgat people in field learn the principle of load factor in one of the first days of 101 lectures on the subject... It least it is an evolution up from "solar isn't working at night" and similar deep and hot takes on the subject.

samatman 3y ago
Pro-nuclear doesn't make one anti-renewables. They're complementary technologies, the rivalry is entirely one-sided. Not to mention incredibly aggravating to those of us who would like power to be reliable, with no emissions.
- asadotzler 3y ago
  The arguments against renewables from your side since at least the '70s when I came across them first, have been persistent and loud, for half a century! You're gonna just pretend that never happened, walk away from it. The parent mentioned the "duh, sun don't shine at night" line because that's some shit your side was for real pushing, for fucking decades. You don't get to sidestep half a lifetime of that garbage and claim some high ground now.
  - samatman 3y ago
    I'm not on whatever side you're having this imaginary argument with. But keep yelling at a cloud if it brings you pleasure.

audunw 3y ago

Keep in mind that looking at the capacity factor for nuclear vs solar/wind can be misleading as well if you don't take into account even more factors. Renewables are composed of a wide mix of thousands of power plants. And these days the construction of renewables goes along with construction of energy storage and grid upgrades (even taking into account those costs, renewables are now competitive). So any failures/downtimes is smoothed out over both time and space. That ~10% of the time that nuclear is down, you get 100s of MWs going down in a single region. France recently had several nuclear power plants go down at the same time, making them dependent on imports for a long stretch of time. In terms of energy I think it's worth looking at the total net energy added. The largest rate that nuclear ever grew was around ~200TWh for some years in the 80s. Solar grew by ~300TWh from 2021 to 2022. Wind grew by ~200TWh. And the growth rate is still increasing exponentially. For reference the world population grew from ~5 to ~8billion from the 80s until now, if you want to take that into account when comparing the growth rates. I don't think there can be any doubt anymore that renewables will completely dominate the energy production in the future.

weberer 3y ago

Here in Finland, the national power grid operator provides a live graph of how much that each source is outputting. Its kind of funny how solar produces almost no energy during the winter this far north. I'm very happy that we have that new 1,600 MW nuclear plant, so we no longer have to get that energy from coal. https://www.fingrid.fi/en/electricity-market/power-system/ https://www.fingrid.fi/en/electricity-market/power-system/

megaman821 3y ago
People want a one-size-fits-all solution, nuclear makes the most sense for the high northern latitudes. Depending on the geography; wind, geothermal and hydro are viable too. Now if you are talking about Egypt, building nuclear over solar/batteries makes absolutely no sense.
- weberer 3y ago
  Yeah, I just don't like how people here are providing a false dichotomy of "renewables vs nuclear" instead of "renewables+nuclear vs fossil fuels". We should put solar panels on every rooftop so we're not throwing away that free* energy, while having nuclear plants as baseload power to smooth out the duck curve. Polar regions need to slide the scale more toward nuclear, while the equatorial regions can go mostly solar. *free as in beer
  - asadotzler 3y ago
    The main reason for me that your scenario isn't ideal is that if we can pull it off, renewables remove significant risk compared to nuclear. When football field of batteries goes up in smoke, some battery money is lost. When a Fukushima happens, an economy can be lost, and a nontrivial number of lives. Thousands or tens of thousands of lives, hundreds of billions or trillions in damages, nah, I'd like to opt out and instead do the extra work to make renewable and safer sources happen. That's how I vote. If you live above the arctic circle you'll likely vote differently and hopefully your next meltdown doesn't reach my shores.

enslavedrobot 3y ago

The LCOE of nuclear is very sensitive to its capacity factor. Nuclear costs are set to skyrocket because for a larger and larger part of the day they will not be profitable as renewables undercut the price of power. With a lower and lower capacity factor, new nuclear plants will never pay for themselves. https://youtu.be/udJJ7n_Ryjg?si=m-F4DNn5MpNvycPA https://youtu.be/udJJ7n_Ryjg?si=m-F4DNn5MpNvycPA