7 ms·

Also it's mandatory to take care of the backup used when there is "no-wind/no-sun". You can have your electricity share coming from renewable that is increasin

Also it's mandatory to take care of the backup used when there is "no-wind/no-sun". You can have your electricity share coming from renewable that is increasing, if in the end you have 30-40 of gaz/coal as a backup to handle the time when renewable is not producing you'll no go way further. Example: Germany.

sveme 4y ago
Care to put some numbers on the no wind/no sun scenario? As an example, the share of renewables in Germany never dropped below 30% last year and that only happened a couple of days. Average renewable contribution was >50%.
- aeyes 4y ago
  I imagine that this is only for the grid production? If I charge my car with solar at home it won't move the meter, energy consumed by households with solar might not show up in the statistics. In reality renewable contribution might be even higher, unless there is correction for this.
- KptMarchewa 4y ago
  Wind in Poland right now works on 2% capacity factor. 152MW out of 7.72GW installed. There is solar now, so renewables are not so bad. However, at 5AM it was bad - wind was only on 5%, zero solar. https://i.imgur.com/LAJ2cKP.png https://i.imgur.com/LAJ2cKP.png
- barney54 4y ago
  What is your source for this? I’m highly skeptical because it means there was never a time of low wind at night ir when it was cloudy. February 26th of last year sure looks like a lot less than 30% renewable. https://mobile.twitter.com/energybants/status/1497392463731908614 https://mobile.twitter.com/energybants/status/14973924637319...
  - sveme 4y ago
    There's also hydro (incl. imported from Norway) and biomass. Source for total renewable over time is here: https://www.zeit.de/wirtschaft/energiemonitor-deutschland-gaspreis-spritpreis-energieversorgung https://www.zeit.de/wirtschaft/energiemonitor-deutschland-ga... There might be spells during the day where this is less than 30%, but that's what short term storage would be there for. The nightmare scenario, often mentioned, is weeks of clouds and low winds, which does not seem to have occurred last year, at least. And even when it's cloudy you still have some solar. By the way, I'm not arguing that all is well and everything is solved, I just hate this juvenile argument of "but what if it's cloudy and there is no wind for weeks", because that does not happen often, especially not on a continent-wide grid with lots of offshore wind power in one of the windiest seas in the world.
    - dahfizz 4y ago
      According to that source, this morning in Germany the total solar + wind + biomass energy production was under 410MWh, whereas gas + coal was around 8500MWh. Conservatively, _just the battery cells_ to make up for that shortfall _for just one hour_ would cost over $1B. This isn't a once in a while issue that can be solved with a few batteries. We need revolutionary grid-scale storage tech to make renewables work. Current batteries are orders-of-magnitude too expensive and we have orders-of-magnitude too little manufacturing capacity.
      - sveme 4y ago
        The problem with these discussions is always that we are laymen using handwaving arguments to push for or against a topic. So useless all in all and just aiming for winning an argument instead of trying to solve a problem. Frustrating. Let's ask Mark Jacobson from Stanford what his modelling shows: https://web.stanford.edu/group/efmh/jacobson/Articles/I/21-USStates-PDFs/21-USStatesPaper.pdf https://web.stanford.edu/group/efmh/jacobson/Articles/I/21-U...
- dahfizz 4y ago
  > the share of renewables in Germany never dropped below 30% last year I find this very hard to believe. There was never a windless night all year? Not for an instant? This[1] seems to disagree. There were plenty of times when wind + solar generation was 3GW or lower, where total usage was over 50GW. If you look at all the electricity generated over the whole of 2022, about half came from renewables. But the grid doesn't operate on averages. Every load needs an instantaneous generation to match. And Germany regularly had times were wind + solar couldn't even meet 10% of demand. [1] https://www.energy-charts.info/charts/power/chart.htm?l=en&c=DE&year=2022&week=09&source=total https://www.energy-charts.info/charts/power/chart.htm?l=en&c...
  - sveme 4y ago
    See my answer above. The load also does not work on ("base") averages, by the way.
acidburnNSA 4y ago
Exactly. In some cases if you do the backup poorly (e.g. with gas like everyone is doing nowadays) you can get into situations where the gas plants run extra inefficiently due to frequent ramping and end up cancelling out a lot of the benefit of your wind and solar. https://www.nrel.gov/docs/fy12osti/53504.pdf https://www.nrel.gov/docs/fy12osti/53504.pdf My favorite fun fact on this is that regular old nuclear plants can ramp up at down quickly, at 5% full per per minute! Most people don't know this. They often choose to not due it because fuel is a small fraction of their operating costs, but in a low-carbon capacity markets they could really shine. French and (previous) German reactor do it all the time. https://www.oecd-nea.org/ndd/reports/2011/load-following-npp.pdf https://www.oecd-nea.org/ndd/reports/2011/load-following-npp...
- ZeroGravitas 4y ago
  From your cited paper's conclusion: > however, these impacts are modest compared with the overall benefits of replacing fossil-fueled generation with variable renewable generation
- starkd 4y ago
  Nuclear makes for such a good backup, you could just dispense with wind and solar altogether and still reduce total carbon output. That might be why they resist doing it. To some extent, the environmental movement has been overtaken by a corporate racket.
  - acidburnNSA 4y ago
    Some in nuclear like to call wind and solar a bridge technology for this reason. Of course we'll need to be more like the S. Koreans and Chinese on our builds before this happens in the west.
  - marcosdumay 4y ago
    What? Nope. Nuclear is completely unsuitable as backup generation. Being backup generation implies that you will optimize for the minimum possible capacity factor. Nuclear can't deal at all with low capacity factors.
Retric 4y ago
New battery backed solar is already cheaper than gas/coal in most areas. This is why the percentage of solar is exploding world wide while nuclear has stagnated. The economics just work out that way. In theory you hit an inflection point at X% wind/solar, but prices just keep falling so it hasn’t happened yet. Germany made a huge sacrifice by subsidizing early and very expensive Solar to in a northern country to really kick things off. But they’re stilly paying subsides on those early installations.
- KptMarchewa 4y ago
  >in most areas Most areas in California, maybe. > This is why the percentage of solar is exploding world wide while nuclear has stagnated. No, solar is exploding because it's heavily subsidized, either monetarily or by other schemes like net metering. Nuclear has stagnated because it requires huge upfront cost, and stability in building new capacity.
  - Retric 4y ago
    No most of the planet. Including Nevada, Texas, … even much of South Dakota. Look at a globe some time, most of the world is much closer to the equator than Germany yet battery backed solar still beats gas/coal/nuclear in parts of southern Germany. PS: Nuclear, coal, and natural gas also receive plenty of subsidies. It turns out removing all subsidies from electricity production actually pushes wind/grid solar even harder. What it discourages is rooftop solar which isn’t a good fit for many locations.
    - bsagdiyev 4y ago
      Those are four states. We're currently without wind and have clouds in Pennsylvania where I'm visiting family, how do you propose we generate enough electricity and cover this coming weekend where there will be rain and clouds.
      - Retric 4y ago
        My list was hardly every state Hawaii and Florida are a great fit for solar. As to PA, this time of year demand is very low as you need minimal heating or cooling. Similarly while solar output is low in stormy weather wind isn’t. Similarly the region has plenty of hydroelectric which can offset production from days with high wind/solar production to days with low wind/solar production. Weather tends to be a tradeoff where hydro and wind improve just as solar and demand decline. In extreme cases like Washington state batteries are pointless and the ideal mix changes.

sveme 4y ago

Care to put some numbers on the no wind/no sun scenario? As an example, the share of renewables in Germany never dropped below 30% last year and that only happened a couple of days. Average renewable contribution was >50%.

aeyes 4y ago
I imagine that this is only for the grid production? If I charge my car with solar at home it won't move the meter, energy consumed by households with solar might not show up in the statistics. In reality renewable contribution might be even higher, unless there is correction for this.
KptMarchewa 4y ago
Wind in Poland right now works on 2% capacity factor. 152MW out of 7.72GW installed. There is solar now, so renewables are not so bad. However, at 5AM it was bad - wind was only on 5%, zero solar. https://i.imgur.com/LAJ2cKP.png https://i.imgur.com/LAJ2cKP.png
barney54 4y ago
What is your source for this? I’m highly skeptical because it means there was never a time of low wind at night ir when it was cloudy. February 26th of last year sure looks like a lot less than 30% renewable. https://mobile.twitter.com/energybants/status/1497392463731908614 https://mobile.twitter.com/energybants/status/14973924637319...
- sveme 4y ago
  There's also hydro (incl. imported from Norway) and biomass. Source for total renewable over time is here: https://www.zeit.de/wirtschaft/energiemonitor-deutschland-gaspreis-spritpreis-energieversorgung https://www.zeit.de/wirtschaft/energiemonitor-deutschland-ga... There might be spells during the day where this is less than 30%, but that's what short term storage would be there for. The nightmare scenario, often mentioned, is weeks of clouds and low winds, which does not seem to have occurred last year, at least. And even when it's cloudy you still have some solar. By the way, I'm not arguing that all is well and everything is solved, I just hate this juvenile argument of "but what if it's cloudy and there is no wind for weeks", because that does not happen often, especially not on a continent-wide grid with lots of offshore wind power in one of the windiest seas in the world.
  - dahfizz 4y ago
    According to that source, this morning in Germany the total solar + wind + biomass energy production was under 410MWh, whereas gas + coal was around 8500MWh. Conservatively, _just the battery cells_ to make up for that shortfall _for just one hour_ would cost over $1B. This isn't a once in a while issue that can be solved with a few batteries. We need revolutionary grid-scale storage tech to make renewables work. Current batteries are orders-of-magnitude too expensive and we have orders-of-magnitude too little manufacturing capacity.
    - sveme 4y ago
      The problem with these discussions is always that we are laymen using handwaving arguments to push for or against a topic. So useless all in all and just aiming for winning an argument instead of trying to solve a problem. Frustrating. Let's ask Mark Jacobson from Stanford what his modelling shows: https://web.stanford.edu/group/efmh/jacobson/Articles/I/21-USStates-PDFs/21-USStatesPaper.pdf https://web.stanford.edu/group/efmh/jacobson/Articles/I/21-U...
dahfizz 4y ago
> the share of renewables in Germany never dropped below 30% last year I find this very hard to believe. There was never a windless night all year? Not for an instant? This[1] seems to disagree. There were plenty of times when wind + solar generation was 3GW or lower, where total usage was over 50GW. If you look at all the electricity generated over the whole of 2022, about half came from renewables. But the grid doesn't operate on averages. Every load needs an instantaneous generation to match. And Germany regularly had times were wind + solar couldn't even meet 10% of demand. [1] https://www.energy-charts.info/charts/power/chart.htm?l=en&c=DE&year=2022&week=09&source=total https://www.energy-charts.info/charts/power/chart.htm?l=en&c...
- sveme 4y ago
  See my answer above. The load also does not work on ("base") averages, by the way.

acidburnNSA 4y ago

Exactly. In some cases if you do the backup poorly (e.g. with gas like everyone is doing nowadays) you can get into situations where the gas plants run extra inefficiently due to frequent ramping and end up cancelling out a lot of the benefit of your wind and solar. https://www.nrel.gov/docs/fy12osti/53504.pdf https://www.nrel.gov/docs/fy12osti/53504.pdf My favorite fun fact on this is that regular old nuclear plants can ramp up at down quickly, at 5% full per per minute! Most people don't know this. They often choose to not due it because fuel is a small fraction of their operating costs, but in a low-carbon capacity markets they could really shine. French and (previous) German reactor do it all the time. https://www.oecd-nea.org/ndd/reports/2011/load-following-npp.pdf https://www.oecd-nea.org/ndd/reports/2011/load-following-npp...

ZeroGravitas 4y ago
From your cited paper's conclusion: > however, these impacts are modest compared with the overall benefits of replacing fossil-fueled generation with variable renewable generation
starkd 4y ago
Nuclear makes for such a good backup, you could just dispense with wind and solar altogether and still reduce total carbon output. That might be why they resist doing it. To some extent, the environmental movement has been overtaken by a corporate racket.
- acidburnNSA 4y ago
  Some in nuclear like to call wind and solar a bridge technology for this reason. Of course we'll need to be more like the S. Koreans and Chinese on our builds before this happens in the west.
- marcosdumay 4y ago
  What? Nope. Nuclear is completely unsuitable as backup generation. Being backup generation implies that you will optimize for the minimum possible capacity factor. Nuclear can't deal at all with low capacity factors.

Retric 4y ago

New battery backed solar is already cheaper than gas/coal in most areas. This is why the percentage of solar is exploding world wide while nuclear has stagnated. The economics just work out that way. In theory you hit an inflection point at X% wind/solar, but prices just keep falling so it hasn’t happened yet. Germany made a huge sacrifice by subsidizing early and very expensive Solar to in a northern country to really kick things off. But they’re stilly paying subsides on those early installations.

KptMarchewa 4y ago
>in most areas Most areas in California, maybe. > This is why the percentage of solar is exploding world wide while nuclear has stagnated. No, solar is exploding because it's heavily subsidized, either monetarily or by other schemes like net metering. Nuclear has stagnated because it requires huge upfront cost, and stability in building new capacity.
- Retric 4y ago
  No most of the planet. Including Nevada, Texas, … even much of South Dakota. Look at a globe some time, most of the world is much closer to the equator than Germany yet battery backed solar still beats gas/coal/nuclear in parts of southern Germany. PS: Nuclear, coal, and natural gas also receive plenty of subsidies. It turns out removing all subsidies from electricity production actually pushes wind/grid solar even harder. What it discourages is rooftop solar which isn’t a good fit for many locations.
  - bsagdiyev 4y ago
    Those are four states. We're currently without wind and have clouds in Pennsylvania where I'm visiting family, how do you propose we generate enough electricity and cover this coming weekend where there will be rain and clouds.
    - Retric 4y ago
      My list was hardly every state Hawaii and Florida are a great fit for solar. As to PA, this time of year demand is very low as you need minimal heating or cooling. Similarly while solar output is low in stormy weather wind isn’t. Similarly the region has plenty of hydroelectric which can offset production from days with high wind/solar production to days with low wind/solar production. Weather tends to be a tradeoff where hydro and wind improve just as solar and demand decline. In extreme cases like Washington state batteries are pointless and the ideal mix changes.