6 ms·

You’re technically right (the best kind of right!) but so is he when he says nuclear approaches 100% CO2. Maybe solar+storage could get even closer close?

mrpopo 7y ago
Most life-cycle estimations argue that solar itself has a higher carbon footprint than nuclear. Solar+storage would be worse. The rationale behind it is simple physics. Enriched nuclear fuel is the most energy-dense material we can access, so unless a new fundamental law is discovered, nuclear energy will have the best EROI, e.g. require the least energy overall to be produced (also note that most of the energy deployed is for security reasons). EDIT: another option for solar+storage to tend towards 0 residual carbon footprint is a life duration 10 or 100 times longer. Something to consider.
- godelski 7y ago
  > Most life-cycle estimations argue that solar itself has a higher carbon footprint than nuclear. Solar+storage would be worse. I'm going to add some nuance. As far as I'm aware, this is only true for photovoltaic solar. My understanding is that concentrated solar (mirrors heat up water tank and you have a steam turbine) has lower lifetime emissions than nuclear. That being said, storage does have a heavy footprint that many ignore. This is a harder number to accurately measure the impact, but if we're talking about a sane fully renewable system you have to have a lot of storage. Places like Southern California can get away with a day or two's worth of storage because there is little variation in conditions. But if you travel up the coast 500 miles things get drastically different. Even more so as you get into Washington. You're going to have to have at least a week's worth of storage. Same thing for the east coast. That said, these options are still better than coal. It is debatable if we're talking about coal + CCS though and likely doesn't beat gas + CCS. Though the counter argument to this is CCS in the manufacturing of your solar and batteries. Again, gets tricky and there's factors to include like tearing down existing coal and gas plants. TLDR: this problem is unsurprisingly extremely complicated even though we make it out to not be.
  - billti 7y ago
    Could a highly efficient grid solve the "local weather" problem? While it might be cloudy in Washington, at the same time it's likely sunny in Nevada, or Texas, (or Mexico if you had cross border production), etc.. The broader the area you can depend on, the less you need "bad weather backup" systems.
    - godelski 7y ago
      Potentially. But there's a big if and quite a few drawbacks. If our power is dependent on such long range travel there is a lot more opportunity for failure. Since we're talking about power, this does mean both lives and millions to billions of dollars worth of economic activity. There's various reasons things could go down. A bird. Russia hacking our grid. Joe Schmoe crashes his truck. You name it. The only way to reduce two of these events is to build a large and complex network with many fail-safes, but that makes the second possibility easier. But if it goes down in Texas we're talking about Northern California, Oregon, and Washington potentially losing power. Having local sources of power is highly reliable and contains disasters to only be local. While I do believe we should have smarter grids there is much wanting in using this as a solution to the regional issues of renewable efficiencies and storage requirements.
    - cycomanic 7y ago
      The answer is yes, there have been studies about this for the US. I'm on mobile now but will try to dig this up later
- readams 7y ago
  nit: while this is true you cannot pick up enriched nuclear fuel off the ground. You have to process many tons of ore. Overall it's still better but this is not guaranteed by simply the energy density of fuel rods.
  - mrpopo 7y ago
    Absolutely, and uranium mining will require more energy over time, as the best sources get depleted. Still, AFAIU, 1) the mining is not the largest energy requirement (security enforcement measures and refining require much more energy and infrastructure) 2) In the golden age of nuclear, it was commonly thought that we would have breeder reactors by now, that would make the fuel processing hundreds of times more efficient, and thus the question would be obsolete... Unfortunately, only India and Russia are still actively working on that technology.
godelski 7y ago
I'm aware I'm splitting hairs. But I bring this up because there are a lot of misconceptions about climate, including the energy sub-problem. I.E. people think if we go renewables (or nuclear) we've solved the climate issue, let alone just the energy problem. Or rather, I think people think all we need is renewables and electric cars. Where in reality even after implementing these two (important) parts we still have a long way to go. And that the idea of this is so prevalent that it is actually hindering progress. So I'm being nuanced. But HN is a place for nuance.
- unethical_ban 7y ago
  What is there, other than energy (and storage/use of it, such as on ships)? My understanding is the VAST majority of climate-change contributions are from energy production and transportation. There are other environmental concerns, but plastic in the ocean isn't raising global temperatures.
  - kcolford 7y ago
    Construction is another big one. Steel and concrete are massive producers of green house gasses
  - godelski 7y ago
    Transportation and energy account for a little under 60% of the problem.[0] (There's a lot more to those than electricity and cars) Another more mainstream issue is agriculture, but people pretty much talk exclusively about water usage and emissions from animal byproducts. This has a political motive. It is the majority of that sector though, to be fair to the vegans. If cows were a country they would be the third worst polluter (please support lab grown meat and reduce your meat intake. Even just eating red meat once a month and chicken the rest of the time has a significant impact on your personal emissions. And please don't bring up cows eating algae). But there's a lot of less sexy parts that we're nowhere even near close to solving. Concrete and steel production is one of them. These are the largest contributor to emissions in construction, and pretty much the only way to solve this issue is with carbon capture and sequestration (CCS) or new materials that we don't yet know about. [1] The same is for plastics. Frankly, we don't have a good way around steel, concrete, or plastics without making some extremely hard compromises. These materials MAKE the modern world and literally save lives. Another less sexy issue is air-conditioning/refrigeration and heating. These systems are almost pure emitters yet we never discuss them. Again, we're nowhere near solving these issues. Again, these technologies save lives and enable the modern world. They are extremely difficult problems and even harder to scale. I'd suggest reading some of Gate's Notes, since they do provide a good high level introduction to the material and I think he is pretty informed on the subject (unfortunately much more than any politician that I'm aware of). I'd start with: A Question To Ask About Every Climate Plan[2]. And then: Climate change and the 75% problem[3]. For another perspective I'll suggest Rees's blog post: Don’t Call Me a Pessimist on Climate Change. I Am a Realist[4] (article includes link to part 2). I work with some climate scientists and these blogs reflect a lot of their concerns (in much more approachable ways). I'm actually deeply upset that the topic has become so politicized. I personally do not feel that either side is taking the issue seriously (though one side is at least acknowledging the problem and partly addressing less than half the problem but also encouraging the infighting. Better than nothing I guess. ¯\_(ツ)_/¯) But if you're wondering why climate scientists outright say: "We're fucked" are are extremely pessimistic, this is a short introduction to why. We don't have the technology to fix the problems, we aren't willing to admit many things are problems, a significant part of the political elite won't acknowledge that the problem even exists, and even if we solved all of this in America that only accounts for 20% of global emissions and how can we ask developing nations to either go without modern technology and let their people die or emit greenhouse gasses? I'm pretty on board with the "we're fucked" sentiment. But I hope we're wrong and I hope people can learn the facts and the non-sexy parts can become of great concern (i.e. get a shit ton of funding). And for the love of god, I hope CCS stops becoming a political topic... [0] https://www.epa.gov/ghgemissions/sources-greenhouse-gas-emissions https://www.epa.gov/ghgemissions/sources-greenhouse-gas-emis.... [1] I personally get upset about the people that don't want to use CCS in gas and coal facilities partly because of this. It is a great way to force mass adoption of these technologies. Plus, it isn't like we can just dump coal at this point. Pretty much for the same reason a heroin addict can't cut cold turkey. We're in too deep /minirant [2] https://www.gatesnotes.com/Energy/A-question-to-ask-about-every-climate-plan https://www.gatesnotes.com/Energy/A-question-to-ask-about-ev... [3] https://www.gatesnotes.com/energy/my-plan-for-fighting-climate-change https://www.gatesnotes.com/energy/my-plan-for-fighting-clima... [4] https://thetyee.ca/Analysis/2019/11/11/Climate-Change-Realist-Face-Facts/ https://thetyee.ca/Analysis/2019/11/11/Climate-Change-Realis...

mrpopo 7y ago

Most life-cycle estimations argue that solar itself has a higher carbon footprint than nuclear. Solar+storage would be worse. The rationale behind it is simple physics. Enriched nuclear fuel is the most energy-dense material we can access, so unless a new fundamental law is discovered, nuclear energy will have the best EROI, e.g. require the least energy overall to be produced (also note that most of the energy deployed is for security reasons). EDIT: another option for solar+storage to tend towards 0 residual carbon footprint is a life duration 10 or 100 times longer. Something to consider.

godelski 7y ago
> Most life-cycle estimations argue that solar itself has a higher carbon footprint than nuclear. Solar+storage would be worse. I'm going to add some nuance. As far as I'm aware, this is only true for photovoltaic solar. My understanding is that concentrated solar (mirrors heat up water tank and you have a steam turbine) has lower lifetime emissions than nuclear. That being said, storage does have a heavy footprint that many ignore. This is a harder number to accurately measure the impact, but if we're talking about a sane fully renewable system you have to have a lot of storage. Places like Southern California can get away with a day or two's worth of storage because there is little variation in conditions. But if you travel up the coast 500 miles things get drastically different. Even more so as you get into Washington. You're going to have to have at least a week's worth of storage. Same thing for the east coast. That said, these options are still better than coal. It is debatable if we're talking about coal + CCS though and likely doesn't beat gas + CCS. Though the counter argument to this is CCS in the manufacturing of your solar and batteries. Again, gets tricky and there's factors to include like tearing down existing coal and gas plants. TLDR: this problem is unsurprisingly extremely complicated even though we make it out to not be.
- billti 7y ago
  Could a highly efficient grid solve the "local weather" problem? While it might be cloudy in Washington, at the same time it's likely sunny in Nevada, or Texas, (or Mexico if you had cross border production), etc.. The broader the area you can depend on, the less you need "bad weather backup" systems.
  - godelski 7y ago
    Potentially. But there's a big if and quite a few drawbacks. If our power is dependent on such long range travel there is a lot more opportunity for failure. Since we're talking about power, this does mean both lives and millions to billions of dollars worth of economic activity. There's various reasons things could go down. A bird. Russia hacking our grid. Joe Schmoe crashes his truck. You name it. The only way to reduce two of these events is to build a large and complex network with many fail-safes, but that makes the second possibility easier. But if it goes down in Texas we're talking about Northern California, Oregon, and Washington potentially losing power. Having local sources of power is highly reliable and contains disasters to only be local. While I do believe we should have smarter grids there is much wanting in using this as a solution to the regional issues of renewable efficiencies and storage requirements.
  - cycomanic 7y ago
    The answer is yes, there have been studies about this for the US. I'm on mobile now but will try to dig this up later
readams 7y ago
nit: while this is true you cannot pick up enriched nuclear fuel off the ground. You have to process many tons of ore. Overall it's still better but this is not guaranteed by simply the energy density of fuel rods.
- mrpopo 7y ago
  Absolutely, and uranium mining will require more energy over time, as the best sources get depleted. Still, AFAIU, 1) the mining is not the largest energy requirement (security enforcement measures and refining require much more energy and infrastructure) 2) In the golden age of nuclear, it was commonly thought that we would have breeder reactors by now, that would make the fuel processing hundreds of times more efficient, and thus the question would be obsolete... Unfortunately, only India and Russia are still actively working on that technology.

godelski 7y ago

I'm aware I'm splitting hairs. But I bring this up because there are a lot of misconceptions about climate, including the energy sub-problem. I.E. people think if we go renewables (or nuclear) we've solved the climate issue, let alone just the energy problem. Or rather, I think people think all we need is renewables and electric cars. Where in reality even after implementing these two (important) parts we still have a long way to go. And that the idea of this is so prevalent that it is actually hindering progress. So I'm being nuanced. But HN is a place for nuance.

unethical_ban 7y ago
What is there, other than energy (and storage/use of it, such as on ships)? My understanding is the VAST majority of climate-change contributions are from energy production and transportation. There are other environmental concerns, but plastic in the ocean isn't raising global temperatures.
- kcolford 7y ago
  Construction is another big one. Steel and concrete are massive producers of green house gasses
- godelski 7y ago
  Transportation and energy account for a little under 60% of the problem.[0] (There's a lot more to those than electricity and cars) Another more mainstream issue is agriculture, but people pretty much talk exclusively about water usage and emissions from animal byproducts. This has a political motive. It is the majority of that sector though, to be fair to the vegans. If cows were a country they would be the third worst polluter (please support lab grown meat and reduce your meat intake. Even just eating red meat once a month and chicken the rest of the time has a significant impact on your personal emissions. And please don't bring up cows eating algae). But there's a lot of less sexy parts that we're nowhere even near close to solving. Concrete and steel production is one of them. These are the largest contributor to emissions in construction, and pretty much the only way to solve this issue is with carbon capture and sequestration (CCS) or new materials that we don't yet know about. [1] The same is for plastics. Frankly, we don't have a good way around steel, concrete, or plastics without making some extremely hard compromises. These materials MAKE the modern world and literally save lives. Another less sexy issue is air-conditioning/refrigeration and heating. These systems are almost pure emitters yet we never discuss them. Again, we're nowhere near solving these issues. Again, these technologies save lives and enable the modern world. They are extremely difficult problems and even harder to scale. I'd suggest reading some of Gate's Notes, since they do provide a good high level introduction to the material and I think he is pretty informed on the subject (unfortunately much more than any politician that I'm aware of). I'd start with: A Question To Ask About Every Climate Plan[2]. And then: Climate change and the 75% problem[3]. For another perspective I'll suggest Rees's blog post: Don’t Call Me a Pessimist on Climate Change. I Am a Realist[4] (article includes link to part 2). I work with some climate scientists and these blogs reflect a lot of their concerns (in much more approachable ways). I'm actually deeply upset that the topic has become so politicized. I personally do not feel that either side is taking the issue seriously (though one side is at least acknowledging the problem and partly addressing less than half the problem but also encouraging the infighting. Better than nothing I guess. ¯\_(ツ)_/¯) But if you're wondering why climate scientists outright say: "We're fucked" are are extremely pessimistic, this is a short introduction to why. We don't have the technology to fix the problems, we aren't willing to admit many things are problems, a significant part of the political elite won't acknowledge that the problem even exists, and even if we solved all of this in America that only accounts for 20% of global emissions and how can we ask developing nations to either go without modern technology and let their people die or emit greenhouse gasses? I'm pretty on board with the "we're fucked" sentiment. But I hope we're wrong and I hope people can learn the facts and the non-sexy parts can become of great concern (i.e. get a shit ton of funding). And for the love of god, I hope CCS stops becoming a political topic... [0] https://www.epa.gov/ghgemissions/sources-greenhouse-gas-emissions https://www.epa.gov/ghgemissions/sources-greenhouse-gas-emis.... [1] I personally get upset about the people that don't want to use CCS in gas and coal facilities partly because of this. It is a great way to force mass adoption of these technologies. Plus, it isn't like we can just dump coal at this point. Pretty much for the same reason a heroin addict can't cut cold turkey. We're in too deep /minirant [2] https://www.gatesnotes.com/Energy/A-question-to-ask-about-every-climate-plan https://www.gatesnotes.com/Energy/A-question-to-ask-about-ev... [3] https://www.gatesnotes.com/energy/my-plan-for-fighting-climate-change https://www.gatesnotes.com/energy/my-plan-for-fighting-clima... [4] https://thetyee.ca/Analysis/2019/11/11/Climate-Change-Realist-Face-Facts/ https://thetyee.ca/Analysis/2019/11/11/Climate-Change-Realis...