4 ms·

You're saying that a couple of 50 year old reactors when including a safety zone and adjusting for lifetime capacity outputs about twice the maximum power of co

You're saying that a couple of 50 year old reactors when including a safety zone and adjusting for lifetime capacity outputs about twice the maximum power of commercial solar panels before adjusting for capacity factor. When you adjust PV for capacity factor the difference ends up at over an order of magnitude.

kempbellt 6y ago
Thought: Put PV inside the "safety zone" to increase output and use "unusable" space.
Retric 6y ago
You’re skipping permits +construction ~10 years and decommissioning which seems to take 30+ years on average though few have actually finished the process. https://en.wikipedia.org/wiki/Nuclear_decommissioning https://en.wikipedia.org/wiki/Nuclear_decommissioning 75% capacity factor * 50y / (50y + 10y construction + ~30y decommissioning) = 42% capacity factor which is higher than solar but not by that much. But let’s assume you’re at a 1.5x capacity factor advantage. So 1.5 GW of solar = 1.0 GW of nuclear. 1.5GW / 220w/m2 = 2.9 square miles of panels plus panel spacing and whatever infrastructure is needed. Double it to be really pessimistic and your under 6 square miles.
- tohmasu 6y ago
  >"So 1.5 GW of solar = 1.0 GW of nuclear." That's not how it works. PV capacity factor is 11-12% to the 90-95% of nuclear meaning you need to install about an order of magnitude more PV effect not 1.5x.
  - tohmasu 6y ago
    Also one batch of PV panels equivalent to a reactor cost 6x as much and with a lifetime of 20 years to the 60 for a nuclear reactor so you will need to replace these at least twice. All 32.5 Million of them.
    - Retric 6y ago
      Replacing panels is just a cost question which dramatically favors solar. 2c/kWh is massively better than any nuclear reactor ever built or operated. As we are talking land use, construction and decommissioning is a major hit to nuclear. But with solar you can operate continuously by just swapping panels and replacing wires etc as needed. Basically, in steady state a 50 year nuclear power plant spends the first 30 years with the previous reactor being decommissioned, and it’s last 10 years with it’s replacement being built. Effectively you need 1.8 locations for a single power plant. Also, I used a specific 75% capacity factor over it’s operating lifespan in that calculation. Some are higher, but the trend is down over time so you want to use an old reactor as your baseline. Here is 72.5% Decommission date 29 June 2020 https://en.wikipedia.org/wiki/Fessenheim_Nuclear_Power_Plant https://en.wikipedia.org/wiki/Fessenheim_Nuclear_Power_Plant
      - tohmasu 6y ago
        Just no. Reactor buildings take up a small fraction of the total site area. Constructing additional reactors on existing sites has been done for about as long as nuclear power has existed and multiple reactors coexist simultaneously at the same site. >"Replacing panels is just a cost question" Sure, I bet you won't need more than 2 guys and a pickup truck to install, maintain and replace the 120 million panels it would take to create the equivalent to a site with 4 modern reactors. After all, that's only 35 000 panels to install every day if you want to build the site in 10 years. Everything is magical with solar. >"2c/kWh" That's a hypothetical figure for 2050.
        Retric 6y ago
        There are actual current contracts that agree to sell solar at under 2c/kWh. Construction of multiple reactors on the same location is very common, constructing a new reactor next to a reactor being decommissioned isn’t. https://en.wikipedia.org/wiki/Crystal_River_Nuclear_Plant https://en.wikipedia.org/wiki/Crystal_River_Nuclear_Plant https://en.wikipedia.org/wiki/Rancho_Seco_Nuclear_Generating_Station https://en.wikipedia.org/wiki/Rancho_Seco_Nuclear_Generating... https://en.wikipedia.org/wiki/Shippingport_Atomic_Power_Station https://en.wikipedia.org/wiki/Shippingport_Atomic_Power_Stat... https://en.wikipedia.org/wiki/San_Onofre_Nuclear_Generating_Station https://en.wikipedia.org/wiki/San_Onofre_Nuclear_Generating_... Etc I mean in theory sure it seems like it should happen, but in practice not so much.

kempbellt 6y ago

Thought: Put PV inside the "safety zone" to increase output and use "unusable" space.

Retric 6y ago

You’re skipping permits +construction ~10 years and decommissioning which seems to take 30+ years on average though few have actually finished the process. https://en.wikipedia.org/wiki/Nuclear_decommissioning https://en.wikipedia.org/wiki/Nuclear_decommissioning 75% capacity factor * 50y / (50y + 10y construction + ~30y decommissioning) = 42% capacity factor which is higher than solar but not by that much. But let’s assume you’re at a 1.5x capacity factor advantage. So 1.5 GW of solar = 1.0 GW of nuclear. 1.5GW / 220w/m2 = 2.9 square miles of panels plus panel spacing and whatever infrastructure is needed. Double it to be really pessimistic and your under 6 square miles.

tohmasu 6y ago
>"So 1.5 GW of solar = 1.0 GW of nuclear." That's not how it works. PV capacity factor is 11-12% to the 90-95% of nuclear meaning you need to install about an order of magnitude more PV effect not 1.5x.
- tohmasu 6y ago
  Also one batch of PV panels equivalent to a reactor cost 6x as much and with a lifetime of 20 years to the 60 for a nuclear reactor so you will need to replace these at least twice. All 32.5 Million of them.
  - Retric 6y ago
    Replacing panels is just a cost question which dramatically favors solar. 2c/kWh is massively better than any nuclear reactor ever built or operated. As we are talking land use, construction and decommissioning is a major hit to nuclear. But with solar you can operate continuously by just swapping panels and replacing wires etc as needed. Basically, in steady state a 50 year nuclear power plant spends the first 30 years with the previous reactor being decommissioned, and it’s last 10 years with it’s replacement being built. Effectively you need 1.8 locations for a single power plant. Also, I used a specific 75% capacity factor over it’s operating lifespan in that calculation. Some are higher, but the trend is down over time so you want to use an old reactor as your baseline. Here is 72.5% Decommission date 29 June 2020 https://en.wikipedia.org/wiki/Fessenheim_Nuclear_Power_Plant https://en.wikipedia.org/wiki/Fessenheim_Nuclear_Power_Plant
    - tohmasu 6y ago
      Just no. Reactor buildings take up a small fraction of the total site area. Constructing additional reactors on existing sites has been done for about as long as nuclear power has existed and multiple reactors coexist simultaneously at the same site. >"Replacing panels is just a cost question" Sure, I bet you won't need more than 2 guys and a pickup truck to install, maintain and replace the 120 million panels it would take to create the equivalent to a site with 4 modern reactors. After all, that's only 35 000 panels to install every day if you want to build the site in 10 years. Everything is magical with solar. >"2c/kWh" That's a hypothetical figure for 2050.
      - Retric 6y ago
        There are actual current contracts that agree to sell solar at under 2c/kWh. Construction of multiple reactors on the same location is very common, constructing a new reactor next to a reactor being decommissioned isn’t. https://en.wikipedia.org/wiki/Crystal_River_Nuclear_Plant https://en.wikipedia.org/wiki/Crystal_River_Nuclear_Plant https://en.wikipedia.org/wiki/Rancho_Seco_Nuclear_Generating_Station https://en.wikipedia.org/wiki/Rancho_Seco_Nuclear_Generating... https://en.wikipedia.org/wiki/Shippingport_Atomic_Power_Station https://en.wikipedia.org/wiki/Shippingport_Atomic_Power_Stat... https://en.wikipedia.org/wiki/San_Onofre_Nuclear_Generating_Station https://en.wikipedia.org/wiki/San_Onofre_Nuclear_Generating_... Etc I mean in theory sure it seems like it should happen, but in practice not so much.