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The comparison with geothermal is flawed for 2 reasons. 1. Geothermal turbines spin at whatever temperature the geothermal steam comes out of the ground. Accord

The comparison with geothermal is flawed for 2 reasons. 1. Geothermal turbines spin at whatever temperature the geothermal steam comes out of the ground. According to the EIA, that's between 150 and 370 Celsius [1]. This is lower than the steam coming from a nuclear reactor. Lower steam temperature means lower thermodynamic efficiency (the ideal Carnot cycle has an efficiency of 1-T_cold/T_hot and all other cycles have an efficiency that is monotonic in T_hot). The second problem with geothermal is the cost of digging the holes, putting the pipes in place, etc. Here's a better comparison. The legendary General Electric turbine LM2500 [2]. GE has built more than 2300 such engines, which operate lots of civilian and military ships and also function as electricity generators in various places. The top of the line such engine is LM2500+G4, which can generate 35 MW and costs about $12 MM. That comes at about $350 MM/GW. That's absolutely negligible compared to the cost of a nuclear power plant, and it is a third of the cost of a solar power plant (see the EIA report [3], page 179, where they estimate a 150 MW such plant to cost - only the components - $172 MM, which translate to $1.15 BN/GW). [1] https://www.eia.gov/energyexplained/geothermal/geothermal-power-plants.php https://www.eia.gov/energyexplained/geothermal/geothermal-po... [2] http://www.fi-powerweb.com/Engine/Industrial/GE-LM2500.html http://www.fi-powerweb.com/Engine/Industrial/GE-LM2500.html [3] https://www.eia.gov/analysis/studies/powerplants/capitalcost/pdf/capital_cost_AEO2020.pdf https://www.eia.gov/analysis/studies/powerplants/capitalcost...

ncmncm 4y ago
Thank you for snagging capital cost figures. $350M/GW is a substantial chunk of what you should hope to pay for a nuke, even though in the US they always cost much more when official, wholly-legal corruption has taken its cut. Solar cap-ex is lately half your figure, but the plummeting price is hard to keep up with. My point was about operating cost, which for a steam turbine includes regular periodic maintenance. Where geothermal operates them at a lower temperature than a nuke, one might expect to need less frequent maintenance, so geo remains a conservative standard of comparison. Of course both nuke and geo have lots of piping to maintain. The point was that solar incurs no such operating cost, besides dusting off the panels once in a while, and inspecting and replacing failed units.
- credit_guy 4y ago
  > no such operating cost, besides dusting off the panels once in a while, and inspecting and replacing failed units. These things add up. Here's a study by NREL (National Renewable Energy Laboratory), which is very unlikely to be biased against solar [1]. On page 31 they estimate the annual costs O&M (operating and maintenance) costs for a 10 MW solar plant at $144k. That comes at $14 MM/GW, or about $350 MM over a lifetime of 25 years. Just so we're clear, I read Austin Vernon's piece about why nukes cannot be economical [2]. It's just not convincing. He compares the thermal part of a nuke with a coal power plant. A coal power plant is much more complex, since it needs to move around millions of tons of coal every year. A better comparison is with natural gas power plants. Luckily, we can check the EIE study I liked to before [3]. I normalize all the costs to 1 GW. Coal (no CO2 capture): $3.7 BN Natural Gas (no CO2 caputure): $0.7 BN (yes, you read that right, it's on page 77) Fuel cells: $6.7 BN Nuclear: $6 BN Geothermal: $2.5 BN Hydro: $5.3 BN Offshore wind: $1.2 BN Onshore wind: $1.7 BN Solar: $1.3 BN So, Austin Vernon's argument that turbines can't be competitive because we've had coal power plants for hundreds of years is simply flawed. Natural gas power plants can be extremely competitive from the CAPEX point of view (of course, they burn gas that costs money, so overall they are not that economical compared to solar). But if you pair the turbine from a state of the art natgas power plant with the steam coming from an inexpensive SMR, there's no reason to not be competitive. [1] https://www.nrel.gov/docs/fy20osti/74840.pdf https://www.nrel.gov/docs/fy20osti/74840.pdf [2] https://austinvernon.site/blog/nuclear.html https://austinvernon.site/blog/nuclear.html [3] https://www.eia.gov/analysis/studies/powerplants/capitalcost/pdf/capital_cost_AEO2020.pdf https://www.eia.gov/analysis/studies/powerplants/capitalcost...
  - ncmncm 4y ago
    NG cost is not declining. Renewables still are.

ncmncm 4y ago

Thank you for snagging capital cost figures. $350M/GW is a substantial chunk of what you should hope to pay for a nuke, even though in the US they always cost much more when official, wholly-legal corruption has taken its cut. Solar cap-ex is lately half your figure, but the plummeting price is hard to keep up with. My point was about operating cost, which for a steam turbine includes regular periodic maintenance. Where geothermal operates them at a lower temperature than a nuke, one might expect to need less frequent maintenance, so geo remains a conservative standard of comparison. Of course both nuke and geo have lots of piping to maintain. The point was that solar incurs no such operating cost, besides dusting off the panels once in a while, and inspecting and replacing failed units.

credit_guy 4y ago
> no such operating cost, besides dusting off the panels once in a while, and inspecting and replacing failed units. These things add up. Here's a study by NREL (National Renewable Energy Laboratory), which is very unlikely to be biased against solar [1]. On page 31 they estimate the annual costs O&M (operating and maintenance) costs for a 10 MW solar plant at $144k. That comes at $14 MM/GW, or about $350 MM over a lifetime of 25 years. Just so we're clear, I read Austin Vernon's piece about why nukes cannot be economical [2]. It's just not convincing. He compares the thermal part of a nuke with a coal power plant. A coal power plant is much more complex, since it needs to move around millions of tons of coal every year. A better comparison is with natural gas power plants. Luckily, we can check the EIE study I liked to before [3]. I normalize all the costs to 1 GW. Coal (no CO2 capture): $3.7 BN Natural Gas (no CO2 caputure): $0.7 BN (yes, you read that right, it's on page 77) Fuel cells: $6.7 BN Nuclear: $6 BN Geothermal: $2.5 BN Hydro: $5.3 BN Offshore wind: $1.2 BN Onshore wind: $1.7 BN Solar: $1.3 BN So, Austin Vernon's argument that turbines can't be competitive because we've had coal power plants for hundreds of years is simply flawed. Natural gas power plants can be extremely competitive from the CAPEX point of view (of course, they burn gas that costs money, so overall they are not that economical compared to solar). But if you pair the turbine from a state of the art natgas power plant with the steam coming from an inexpensive SMR, there's no reason to not be competitive. [1] https://www.nrel.gov/docs/fy20osti/74840.pdf https://www.nrel.gov/docs/fy20osti/74840.pdf [2] https://austinvernon.site/blog/nuclear.html https://austinvernon.site/blog/nuclear.html [3] https://www.eia.gov/analysis/studies/powerplants/capitalcost/pdf/capital_cost_AEO2020.pdf https://www.eia.gov/analysis/studies/powerplants/capitalcost...
- ncmncm 4y ago
  NG cost is not declining. Renewables still are.