2 ms·

http://www.nature.com/climate/2008/0810/full/climate.2008.99.html http://www.nature.com/climate/2008/0810/full/climate.2008.99... Unless this 2008 article has

http://www.nature.com/climate/2008/0810/full/climate.2008.99.html http://www.nature.com/climate/2008/0810/full/climate.2008.99... Unless this 2008 article has been debunked or something, it doesn't sound like nuclear power is GHG free.

philipkglass 10y ago
No energy source is completely free of GHG emissions over its full life cycle. As you can see from my other posts I am pretty bullish about renewables but this particular article advances some bad arguments. According to Sovacool's analysis, nuclear power, at 66 gCO2e/kWh emissions is well below scrubbed coal-fired plants, which emit 960 gCO2e/kWh, and natural gas-fired plants, at 443 gCO2e/kWh. However, nuclear emits twice as much carbon as solar photovoltaic, at 32 gCO2e/kWh, and six times as much as onshore wind farms, at 10 gCO2e/kWh. "A number in the 60s puts it well below natural gas, oil, coal and even clean-coal technologies. On the other hand, things like energy efficiency, and some of the cheaper renewables are a factor of six better. So for every dollar you spend on nuclear, you could have saved five or six times as much carbon with efficiency, or wind farms," Sovacool says. 1) Even if we use the input numbers for his model, the amount of emissions you save is calculated against the fossil status quo. (At least until fossil use is basically gone and it's all just non-fossil sources competing with each other.) If the baseline is 443 for natural gas, every kWh produced from nuclear saves (443 - 66) = 377 grams, and every kWh produced from offshore wind saves (443 - 10) = 433 grams. A kWh of offshore wind saves 56 additional grams per kWh against a gas baseline, 15% better than nuclear, not 600% better. 2) He's blithely switching between currency units and energy units. A dollar's worth of offshore wind investment produced significantly less lifetime energy in 2008 than a dollar's worth of nuclear power investment. Even after 8 years of falling offshore wind costs and rising nuclear costs, crossover has been achieved only very recently. 3) The largest single part of nuclear emissions in his analysis comes from fuel enrichment at the front end. This was because there were still old, inefficient, gaseous diffusion enrichment plants operating in 2008 in the United States and France. Both are now closed, so the West enriches uranium only via centrifuge, which has much lower energy requirements and corresponding emissions.

philipkglass 10y ago

No energy source is completely free of GHG emissions over its full life cycle. As you can see from my other posts I am pretty bullish about renewables but this particular article advances some bad arguments. According to Sovacool's analysis, nuclear power, at 66 gCO2e/kWh emissions is well below scrubbed coal-fired plants, which emit 960 gCO2e/kWh, and natural gas-fired plants, at 443 gCO2e/kWh. However, nuclear emits twice as much carbon as solar photovoltaic, at 32 gCO2e/kWh, and six times as much as onshore wind farms, at 10 gCO2e/kWh. "A number in the 60s puts it well below natural gas, oil, coal and even clean-coal technologies. On the other hand, things like energy efficiency, and some of the cheaper renewables are a factor of six better. So for every dollar you spend on nuclear, you could have saved five or six times as much carbon with efficiency, or wind farms," Sovacool says. 1) Even if we use the input numbers for his model, the amount of emissions you save is calculated against the fossil status quo. (At least until fossil use is basically gone and it's all just non-fossil sources competing with each other.) If the baseline is 443 for natural gas, every kWh produced from nuclear saves (443 - 66) = 377 grams, and every kWh produced from offshore wind saves (443 - 10) = 433 grams. A kWh of offshore wind saves 56 additional grams per kWh against a gas baseline, 15% better than nuclear, not 600% better. 2) He's blithely switching between currency units and energy units. A dollar's worth of offshore wind investment produced significantly less lifetime energy in 2008 than a dollar's worth of nuclear power investment. Even after 8 years of falling offshore wind costs and rising nuclear costs, crossover has been achieved only very recently. 3) The largest single part of nuclear emissions in his analysis comes from fuel enrichment at the front end. This was because there were still old, inefficient, gaseous diffusion enrichment plants operating in 2008 in the United States and France. Both are now closed, so the West enriches uranium only via centrifuge, which has much lower energy requirements and corresponding emissions.