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A little over 20% of US electricity is generated from coal. There are around 2400 coal power plants in the world. My understanding is that if we could turn off

A little over 20% of US electricity is generated from coal. There are around 2400 coal power plants in the world. My understanding is that if we could turn off all the coal plants tomorrow we could actually significantly reduce greenhouse gas emissions. Would it buy us a significant amount of time if we accelerated the conversation to natural gas?

abejfehr 6y ago
I don't think natural gas is actually a carbon-neutral alternative to coal, my understanding is that methane leakage makes it almost as bad as coal in the long term. https://www.vox.com/energy-and-environment/2019/5/30/18643819/climate-change-natural-gas-middle-ground https://www.vox.com/energy-and-environment/2019/5/30/1864381...
- causality0 6y ago
  True, but it doesn't have the incredibly horrific non-carbon pollution problems of coal. The things almost every coal plant in the world does to nearby rivers would nauseate most people. Fly ash produced by coal plants releases one hundred times the radiation into the environment as a nuclear plant of the same capacity.
  - avalys 6y ago
    That’s only true because the amount of radiation released by a nuclear plant in normal operation is also negligible.
    - willis936 6y ago
      The actual number closer to 1,000 than 100. There is a lot of uranium and thorium in coal. Not all of it is captured when coal is burned. https://www.scientificamerican.com/article/coal-ash-is-more-radioactive-than-nuclear-waste/ https://www.scientificamerican.com/article/coal-ash-is-more-...
      - makomk 6y ago
        "A lot" is relative. From what I can tell, coal ash contains about the same amount of uranium and thorium as granite and slightly more than ordinary soil. (Of course, it's less concentrated in the coal itself, which is largely carbon and hydrocarbons that gets burnt off.) The main reason coal power releases so much radiation compared to nuclear because there's a lot of coal burnt and normal operation of nuclear power plants also releases very little. What's more scary is the production of things like rare earth minerals - that quite heavily concentrates the uranium and thorium as part of the extraction process, producing large quantities of relatively radioactive mining waste.
- jweir 6y ago
  Methane breaks down much faster than carbon and methane leaks can be mitigated. You don’t have to have them.
  - Nasrudith 6y ago
    It breaks down into carbdon dioxide.
- marcosdumay 6y ago
  Coal leaks methane too. A while ago there were people here pointing that even more than natural gas; I'm not convinced, but both are on the same ballpark. Anyway, methane is a short term problem. It's CO2 that is long term.
- melling 6y ago
  I didn’t say it was carbon neutral. Coal adds much more CO2 to the atmosphere. At least twice as much? Rather than losing more time waiting for the perfect solution, a big step 10 years earlier might buy us additional time.
- fuoqi 6y ago
  A LOT of methane is released during coal mining as well, it's estimated that 9% of total global methane emissions can be attributed to it: https://www.epa.gov/cmop/frequent-questions#q6 https://www.epa.gov/cmop/frequent-questions#q6
- joe-collins 6y ago
  It isn't neutral at all, it's merely less-intensive. Leakage is a problem with straightforward extant solutions, but well operators are poorly incentivized to implement those solutions—the loss is often too small to substantially impact their profit, and the leak is invisible (natural gas being colorless) so it's easy to turn a blind eye and not implement effective monitoring.
  - iamthemonster 6y ago
    I'm not sure how we would implement any more effective monitoring of natural gas leakage. We have gas detectors all over the facility and personnel walk around with gas detectors on their coveralls. Flowmeters are generally not accurate to <1%. I would expect the only credible thing we can do is design it out, e.g. by running seal vents to flare rather than safe location, improving reliability, flareless operation etc. I imagine the majority of "leakage" must be unburnt hydrocarbon in flare and GT exhausts. But when you say "straightforward extant solutions" what are you referring to? In the industry, nobody particularly assesses "leakage" or really designs for minimising leakage per se.
    - londons_explore 6y ago
      It could be mandated that all facility pressures be below atmospheric pressure. Then all leaks would lead to air getting into the pipes rather than gas getting out. Clearly with that being the case, one needs much bigger more expensive pipes.
      - treeman79 6y ago
        Had my lungs ruined by natural gas leaks. This solution sounds very scary.
      - iamthemonster 6y ago
        That would easily solve the problem, by making any gas processing facilities completely uneconomic to operate ;) I am quite interested in the idea of methane leakage though. There seems to be a growing consensus online that it exists and is significant, but within industry it is really not recognised.
- reitzensteinm 6y ago
  Don't you mean the short term? Methane being a very potent greenhouse gas but it breaks down with time.
- ekianjo 6y ago
  Natural gas is way cleaner than coal overall. It does not release particles that kill people over the long term either. It's a pretty clear cut between the two.
  - lysp 6y ago
    If you only compare the burning stage.
toomuchtodo 6y ago
With the current cost of solar and wind, coal->natural gas conversions aren't a slam dunk for utilities or investor owned generators. > Coal power plants in the US have been retiring at an average clip of 10 gigawatts per year as the clean energy transition takes hold. That may sound impressive, but it’s not nearly quick enough, considering that climate change is already buffeting the Earth. The pace has to pick up quickly in order to avoid more catastrophe. That’s where a new thing called solar-for-coal swaps comes in. The “swap” part is a bit complicated, but if the idea catches hold it could speed up coal power plant retirements and skim more than 20 gigawatts right off the top. > In a new white paper, the clean energy group Energy Innovation has identified some low hanging coal fruit, in the form of 179 gigawatts that can’t compete on cost with solar any more. These coal units are still operating for various reasons even though solar saves money, but Energy Innovation has picked out a group of 22.5 gigawatts that could be rolled over in short order. https://cleantechnica.com/2020/08/09/solar-for-coal-swaps-could-turbocharge-clean-energy-revolution-cleantechnica-interview/ https://cleantechnica.com/2020/08/09/solar-for-coal-swaps-co...
cagenut 6y ago
> My understanding is that if we could turn off all the coal plants tomorrow we could actually significantly reduce greenhouse gas emissions. yes. in 2018 40% of all CO2 emissions were from coal: https://ourworldindata.org/co2-and-other-greenhouse-gas-emissions#co2-emissions-by-fuel https://ourworldindata.org/co2-and-other-greenhouse-gas-emis... that graph is the simplest possible way to think about "dealing with climate change". Its a checklist: #1 coal. #2 oil. #3 gas. Gas has been a "transitional" fuel in the sense that its made the last decade less bad than it would have been, but given the timeline left* its already too late to build new gas infrastructure, assuming you intend to finance it with 30 year bonds. * per the ipcc in order to stay under 2C emissions need to hit zero somewhere between 2040 for rich/western countries and 2055 for the whole planet, and then be followed by negative emissions for the rest of the century
hinkley 6y ago
From the article, only 49 of 316 GW (16%) of coal capacity was replaced in eight years. This is Detroit and fuel efficiency all over again. Look how good we are doing dragging our feet! (Even though the results allow a lot of cool things).
cwojno 6y ago
No, quite the opposite, actually. Natural gas conversion mostly reduces particulates. The EIA data says natural gas produces more CO2/MkWh than coal: Electricity generation CO2 emissions million kWh million metric tons million short tons pounds per kWh Coal 1,124,638 1,127 1,240 2.21 Natural gas 1,246,847 523 575 0.92 Petroleum 21,860 21 23 2.11 https://www.eia.gov/tools/faqs/faq.php?id=74&t=11 https://www.eia.gov/tools/faqs/faq.php?id=74&t=11 Ironically, particulates decrease insolation and actually slightly reduce warming (CO2's half life is a lot longer than particulates, so the "cooling" is short-lived and will go away when you stop burning coal, net warming, overall). Natural gas doesn't produce as many particulates, so I would expect that converting to natural gas would increase global warming in the short and long term compared to continue to burn coal. It's far better to switch to solar/wind/geo/nuclear than natural gas in the long run, but there are health benefits to removing the coal particulates: "Coal impacts: air pollution When coal is burned it releases a number of airborne toxins and pollutants. They include mercury, lead, sulfur dioxide, nitrogen oxides, particulates, and various other heavy metals. Health impacts can range from asthma and breathing difficulties, to brain damage, heart problems, cancer, neurological disorders, and premature death." https://www.ucsusa.org/resources/coal-power-impacts#:~:text=Coal%20and%20Air%20Pollution,environmental%20and%20public%20health%20impacts https://www.ucsusa.org/resources/coal-power-impacts#:~:text=.... I presume that the primary driver of this conversion isn't the environment, but economics. The price of coal/kWh is more expensive than the volume of gas required to generate the same kWh. The Total system LCOE is usually the number people want to minimize. https://www.eia.gov/outlooks/aeo/pdf/electricity_generation.pdf https://www.eia.gov/outlooks/aeo/pdf/electricity_generation.... tl;dr: No. Burning gas is worse from a climate perspective.
- phonon 6y ago
  Errr, probably you should read it again? Natural gas has about half the CO2 emissions per unit of energy as coal. Maybe this[1] or this[2] is clearer. [1] https://www.eia.gov/environment/emissions/co2_vol_mass.php https://www.eia.gov/environment/emissions/co2_vol_mass.php [2] https://www.eia.gov/electricity/annual/html/epa_a_03.html https://www.eia.gov/electricity/annual/html/epa_a_03.html
  - 6y ago

abejfehr 6y ago

I don't think natural gas is actually a carbon-neutral alternative to coal, my understanding is that methane leakage makes it almost as bad as coal in the long term. https://www.vox.com/energy-and-environment/2019/5/30/18643819/climate-change-natural-gas-middle-ground https://www.vox.com/energy-and-environment/2019/5/30/1864381...

causality0 6y ago
True, but it doesn't have the incredibly horrific non-carbon pollution problems of coal. The things almost every coal plant in the world does to nearby rivers would nauseate most people. Fly ash produced by coal plants releases one hundred times the radiation into the environment as a nuclear plant of the same capacity.
- avalys 6y ago
  That’s only true because the amount of radiation released by a nuclear plant in normal operation is also negligible.
  - willis936 6y ago
    The actual number closer to 1,000 than 100. There is a lot of uranium and thorium in coal. Not all of it is captured when coal is burned. https://www.scientificamerican.com/article/coal-ash-is-more-radioactive-than-nuclear-waste/ https://www.scientificamerican.com/article/coal-ash-is-more-...
    - makomk 6y ago
      "A lot" is relative. From what I can tell, coal ash contains about the same amount of uranium and thorium as granite and slightly more than ordinary soil. (Of course, it's less concentrated in the coal itself, which is largely carbon and hydrocarbons that gets burnt off.) The main reason coal power releases so much radiation compared to nuclear because there's a lot of coal burnt and normal operation of nuclear power plants also releases very little. What's more scary is the production of things like rare earth minerals - that quite heavily concentrates the uranium and thorium as part of the extraction process, producing large quantities of relatively radioactive mining waste.
jweir 6y ago
Methane breaks down much faster than carbon and methane leaks can be mitigated. You don’t have to have them.
- Nasrudith 6y ago
  It breaks down into carbdon dioxide.
marcosdumay 6y ago
Coal leaks methane too. A while ago there were people here pointing that even more than natural gas; I'm not convinced, but both are on the same ballpark. Anyway, methane is a short term problem. It's CO2 that is long term.
melling 6y ago
I didn’t say it was carbon neutral. Coal adds much more CO2 to the atmosphere. At least twice as much? Rather than losing more time waiting for the perfect solution, a big step 10 years earlier might buy us additional time.
fuoqi 6y ago
A LOT of methane is released during coal mining as well, it's estimated that 9% of total global methane emissions can be attributed to it: https://www.epa.gov/cmop/frequent-questions#q6 https://www.epa.gov/cmop/frequent-questions#q6
joe-collins 6y ago
It isn't neutral at all, it's merely less-intensive. Leakage is a problem with straightforward extant solutions, but well operators are poorly incentivized to implement those solutions—the loss is often too small to substantially impact their profit, and the leak is invisible (natural gas being colorless) so it's easy to turn a blind eye and not implement effective monitoring.
- iamthemonster 6y ago
  I'm not sure how we would implement any more effective monitoring of natural gas leakage. We have gas detectors all over the facility and personnel walk around with gas detectors on their coveralls. Flowmeters are generally not accurate to <1%. I would expect the only credible thing we can do is design it out, e.g. by running seal vents to flare rather than safe location, improving reliability, flareless operation etc. I imagine the majority of "leakage" must be unburnt hydrocarbon in flare and GT exhausts. But when you say "straightforward extant solutions" what are you referring to? In the industry, nobody particularly assesses "leakage" or really designs for minimising leakage per se.
  - londons_explore 6y ago
    It could be mandated that all facility pressures be below atmospheric pressure. Then all leaks would lead to air getting into the pipes rather than gas getting out. Clearly with that being the case, one needs much bigger more expensive pipes.
    - treeman79 6y ago
      Had my lungs ruined by natural gas leaks. This solution sounds very scary.
    - iamthemonster 6y ago
      That would easily solve the problem, by making any gas processing facilities completely uneconomic to operate ;) I am quite interested in the idea of methane leakage though. There seems to be a growing consensus online that it exists and is significant, but within industry it is really not recognised.
reitzensteinm 6y ago
Don't you mean the short term? Methane being a very potent greenhouse gas but it breaks down with time.
ekianjo 6y ago
Natural gas is way cleaner than coal overall. It does not release particles that kill people over the long term either. It's a pretty clear cut between the two.
- lysp 6y ago
  If you only compare the burning stage.

toomuchtodo 6y ago

With the current cost of solar and wind, coal->natural gas conversions aren't a slam dunk for utilities or investor owned generators. > Coal power plants in the US have been retiring at an average clip of 10 gigawatts per year as the clean energy transition takes hold. That may sound impressive, but it’s not nearly quick enough, considering that climate change is already buffeting the Earth. The pace has to pick up quickly in order to avoid more catastrophe. That’s where a new thing called solar-for-coal swaps comes in. The “swap” part is a bit complicated, but if the idea catches hold it could speed up coal power plant retirements and skim more than 20 gigawatts right off the top. > In a new white paper, the clean energy group Energy Innovation has identified some low hanging coal fruit, in the form of 179 gigawatts that can’t compete on cost with solar any more. These coal units are still operating for various reasons even though solar saves money, but Energy Innovation has picked out a group of 22.5 gigawatts that could be rolled over in short order. https://cleantechnica.com/2020/08/09/solar-for-coal-swaps-could-turbocharge-clean-energy-revolution-cleantechnica-interview/ https://cleantechnica.com/2020/08/09/solar-for-coal-swaps-co...

cagenut 6y ago

> My understanding is that if we could turn off all the coal plants tomorrow we could actually significantly reduce greenhouse gas emissions. yes. in 2018 40% of all CO2 emissions were from coal: https://ourworldindata.org/co2-and-other-greenhouse-gas-emissions#co2-emissions-by-fuel https://ourworldindata.org/co2-and-other-greenhouse-gas-emis... that graph is the simplest possible way to think about "dealing with climate change". Its a checklist: #1 coal. #2 oil. #3 gas. Gas has been a "transitional" fuel in the sense that its made the last decade less bad than it would have been, but given the timeline left* its already too late to build new gas infrastructure, assuming you intend to finance it with 30 year bonds. * per the ipcc in order to stay under 2C emissions need to hit zero somewhere between 2040 for rich/western countries and 2055 for the whole planet, and then be followed by negative emissions for the rest of the century

hinkley 6y ago

From the article, only 49 of 316 GW (16%) of coal capacity was replaced in eight years. This is Detroit and fuel efficiency all over again. Look how good we are doing dragging our feet! (Even though the results allow a lot of cool things).

cwojno 6y ago

No, quite the opposite, actually. Natural gas conversion mostly reduces particulates. The EIA data says natural gas produces more CO2/MkWh than coal: Electricity generation CO2 emissions million kWh million metric tons million short tons pounds per kWh Coal 1,124,638 1,127 1,240 2.21 Natural gas 1,246,847 523 575 0.92 Petroleum 21,860 21 23 2.11 https://www.eia.gov/tools/faqs/faq.php?id=74&t=11 https://www.eia.gov/tools/faqs/faq.php?id=74&t=11 Ironically, particulates decrease insolation and actually slightly reduce warming (CO2's half life is a lot longer than particulates, so the "cooling" is short-lived and will go away when you stop burning coal, net warming, overall). Natural gas doesn't produce as many particulates, so I would expect that converting to natural gas would increase global warming in the short and long term compared to continue to burn coal. It's far better to switch to solar/wind/geo/nuclear than natural gas in the long run, but there are health benefits to removing the coal particulates: "Coal impacts: air pollution When coal is burned it releases a number of airborne toxins and pollutants. They include mercury, lead, sulfur dioxide, nitrogen oxides, particulates, and various other heavy metals. Health impacts can range from asthma and breathing difficulties, to brain damage, heart problems, cancer, neurological disorders, and premature death." https://www.ucsusa.org/resources/coal-power-impacts#:~:text=Coal%20and%20Air%20Pollution,environmental%20and%20public%20health%20impacts https://www.ucsusa.org/resources/coal-power-impacts#:~:text=.... I presume that the primary driver of this conversion isn't the environment, but economics. The price of coal/kWh is more expensive than the volume of gas required to generate the same kWh. The Total system LCOE is usually the number people want to minimize. https://www.eia.gov/outlooks/aeo/pdf/electricity_generation.pdf https://www.eia.gov/outlooks/aeo/pdf/electricity_generation.... tl;dr: No. Burning gas is worse from a climate perspective.

phonon 6y ago
Errr, probably you should read it again? Natural gas has about half the CO2 emissions per unit of energy as coal. Maybe this[1] or this[2] is clearer. [1] https://www.eia.gov/environment/emissions/co2_vol_mass.php https://www.eia.gov/environment/emissions/co2_vol_mass.php [2] https://www.eia.gov/electricity/annual/html/epa_a_03.html https://www.eia.gov/electricity/annual/html/epa_a_03.html
- 6y ago