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It is on par with solar with respect to the emissions per kW. Nuclear power plants emit virtually no radiation when properly operated and maintained (indeed, co

It is on par with solar with respect to the emissions per kW. Nuclear power plants emit virtually no radiation when properly operated and maintained (indeed, coal power plants emit more radiation into the environment). In rare cases, accidents happen, but the risk adjusted cost of those accidents is negligible compared to fossil fuel power. I’m not sure what “radioactive impacts” derive from mining Uranium, but I doubt it’s non-negligible compared to the harm imposed my fossil fuels.

ajsnigrutin 5y ago
And compared to solar, they produce power even during cold, winter nights, when you need heat the most. It's not the most efficiant way to heat your homes (fission -> heat -> water -> steam engine -> electricity -> heater), but it brings autonomy to each country (so global issues don't affect your country), and with heat pumps, it's not even that bad at heating.
- coryrc 5y ago
  Add in district heating and you get cheap heat too. Europe is often dense enough for this to work...
- bialpio 5y ago
  I was under the impression that the last step can potentially be made pretty efficient if it's "electricity -> heat pump" (but that depends on the conditions). Also - can nuclear power plants operate in combined heat and power mode to provide district heating? That'd probably require them to be close to highly populated areas though.
Teknoman117 5y ago
Nuclear (fission) beats out solar for the most part in terms of CO2 equivalent per kW/h of energy generation. The 6-grams CO2 equivalent per kW/h figure assumes the panel is in ideal conditions (receiving sun for all sun-up hours during the year at equatorial to middle latitudes and operating at a fixed temperature). For a place like Finland, Norway, or Sweden, this goes up 50-grams CO2 equivalent per kW/h (less power produced over lifespan given a fixed manufacturing footprint). Nuclear is at 4-grams per kW/h. Wind is also about 4-grams per kW/h (again, assuming ideal conditions). Meanwhile, the most efficient coal fired plants are like 700 grams of CO2 per kW/h and most are at 1000-1200 grams per kW/h...
- lacksconfidence 5y ago
  I realize you didn't invent these terms, but is kW/h the right metric? A plain reading of the units provided suggests 700 grams of CO2 is released every hour for every kW generated, but that seems unlikely. Where does the per hour figure in?
  - throwaway894345 5y ago
    It's almost exactly 1kg per kw/h, at least in the US: https://www.eia.gov/tools/faqs/faq.php?id=74&t=11 https://www.eia.gov/tools/faqs/faq.php?id=74&t=11 But yes, "per hour" is necessary because you can't instantaneously emit a certain mass of co2. You emit over time, just like you generate power over time.
  - jeltz 5y ago
    I suspect it is a typo and that it should be grams per kWh.
  - Teknoman117 5y ago
    I meant kWh. The units derivation is as follows if I remember correctly: The SI unit for some absolute quantity of energy is the "Joule". 1 watt = 1 joule per second (1 J/s) Watts can sort of be thought of as the rate at which some absolute quantity of energy is available or able to be consumed. Since energy sources are usually rated in terms of their ability to supply an instantaneous amount of power, in order to get back to the absolute amount of energy, you need to multiply by the time in order to get back to just some multiple of joules. 1 watt-second = 1 J/s * s = 1 J. So the concept holds that if we are going to measure some amount of something (other than power) produced by a power plant, it should be measured against the absolute amount of power produced. Obviously this doesn't take into account the fact that pollution generated by some forms of power aren't linearly correlated with the power produced - e.g. fossil fuel plants produce less particulate pollution the hotter the fire burns, meaning they get dirtier vs the power output the lower the output power is set. Hence why gas turbines burn cleaner that gas-fired steam generators (hand waving over the efficiency differences of direct fired turbines versus steam generation). Another data point is that natural gas turbines (again, averages from the US) produce 550 grams per kWh, and combined cycle (adding a second turbine that runs off the exhaust heat of the first) are 435 grams CO2 per kWh. But the numbers I posted are what I meant. In the US, an average of one kilogram of CO2 is emitted per kilowatt-hour of energy (3.6 * 10^6 Joules) generated. Nuclear is two orders of magnitude less carbon emission (versus coal), wind and solar are comparable if deployed under ideal conditions. Even under non-ideal conditions, they still offer an order of magnitude improvement.

ajsnigrutin 5y ago

And compared to solar, they produce power even during cold, winter nights, when you need heat the most. It's not the most efficiant way to heat your homes (fission -> heat -> water -> steam engine -> electricity -> heater), but it brings autonomy to each country (so global issues don't affect your country), and with heat pumps, it's not even that bad at heating.

coryrc 5y ago
Add in district heating and you get cheap heat too. Europe is often dense enough for this to work...
bialpio 5y ago
I was under the impression that the last step can potentially be made pretty efficient if it's "electricity -> heat pump" (but that depends on the conditions). Also - can nuclear power plants operate in combined heat and power mode to provide district heating? That'd probably require them to be close to highly populated areas though.

Teknoman117 5y ago

Nuclear (fission) beats out solar for the most part in terms of CO2 equivalent per kW/h of energy generation. The 6-grams CO2 equivalent per kW/h figure assumes the panel is in ideal conditions (receiving sun for all sun-up hours during the year at equatorial to middle latitudes and operating at a fixed temperature). For a place like Finland, Norway, or Sweden, this goes up 50-grams CO2 equivalent per kW/h (less power produced over lifespan given a fixed manufacturing footprint). Nuclear is at 4-grams per kW/h. Wind is also about 4-grams per kW/h (again, assuming ideal conditions). Meanwhile, the most efficient coal fired plants are like 700 grams of CO2 per kW/h and most are at 1000-1200 grams per kW/h...

lacksconfidence 5y ago
I realize you didn't invent these terms, but is kW/h the right metric? A plain reading of the units provided suggests 700 grams of CO2 is released every hour for every kW generated, but that seems unlikely. Where does the per hour figure in?
- throwaway894345 5y ago
  It's almost exactly 1kg per kw/h, at least in the US: https://www.eia.gov/tools/faqs/faq.php?id=74&t=11 https://www.eia.gov/tools/faqs/faq.php?id=74&t=11 But yes, "per hour" is necessary because you can't instantaneously emit a certain mass of co2. You emit over time, just like you generate power over time.
- jeltz 5y ago
  I suspect it is a typo and that it should be grams per kWh.
- Teknoman117 5y ago
  I meant kWh. The units derivation is as follows if I remember correctly: The SI unit for some absolute quantity of energy is the "Joule". 1 watt = 1 joule per second (1 J/s) Watts can sort of be thought of as the rate at which some absolute quantity of energy is available or able to be consumed. Since energy sources are usually rated in terms of their ability to supply an instantaneous amount of power, in order to get back to the absolute amount of energy, you need to multiply by the time in order to get back to just some multiple of joules. 1 watt-second = 1 J/s * s = 1 J. So the concept holds that if we are going to measure some amount of something (other than power) produced by a power plant, it should be measured against the absolute amount of power produced. Obviously this doesn't take into account the fact that pollution generated by some forms of power aren't linearly correlated with the power produced - e.g. fossil fuel plants produce less particulate pollution the hotter the fire burns, meaning they get dirtier vs the power output the lower the output power is set. Hence why gas turbines burn cleaner that gas-fired steam generators (hand waving over the efficiency differences of direct fired turbines versus steam generation). Another data point is that natural gas turbines (again, averages from the US) produce 550 grams per kWh, and combined cycle (adding a second turbine that runs off the exhaust heat of the first) are 435 grams CO2 per kWh. But the numbers I posted are what I meant. In the US, an average of one kilogram of CO2 is emitted per kilowatt-hour of energy (3.6 * 10^6 Joules) generated. Nuclear is two orders of magnitude less carbon emission (versus coal), wind and solar are comparable if deployed under ideal conditions. Even under non-ideal conditions, they still offer an order of magnitude improvement.