4 ms·

That is untrue as well. Inflexibility isn't the problem, the cost profile is. Yes, nobody likes running nuclear at half power, because fuel costs are minute com

by corty 5y ago

That is untrue as well. Inflexibility isn't the problem, the cost profile is. Yes, nobody likes running nuclear at half power, because fuel costs are minute compared to the building cost of the plant (Btw that is exactly analogous to the cost profile of renewables: almost all cost is in the building). So as long as you can regulate some pumped hydro plants that, shed some load, etc, you may save some money. Why don't we do load following with renewables, like e.g. shutting off some wind turbines? Same reason as for nuclear, plus some government regulations. And in general, renewables do need a flexible supplement. So what would you suggest? More pumped hydro is impossible to build due to environmental regs, NIMBY and geography. Coal and lignite isn't flexible at all, and it is coal. Gas is extremely expensive to run, so expensive that there are gas peaker plants on idle for years in Germany. Also, they are burning gas. Bio gas is not available in sufficient capacity. Battery storage might be an option 30 years from now when enough old EV batteries are available on the cheap. But that will prevent recycling them into new EV batteries and need even more resources like lithium and cobalt. So the alternatives to nuclear like coal and gas are worse, and only still in use because they don't pay fair a price on their carbon emissions.

pfdietz 5y ago
No, it's not untrue. If you optimize a CO2-free grid for minimum cost, you will find that the solutions don't usually involve both renewables (particularly wind) and nuclear. Either nuclear is so expensive it goes to zero, or its so cheap it dominates. There's little synergy between renewables and nuclear. This also happens in unplanned grids where market forces are being allowed to operate. Renewables, if they are cheaper per kWh than nuclear, drive down the price sufficiently often that nuclear struggles (and with production subsidies, they can drive prices negative, but never mind that). Today, even existing nuclear plants are struggling to make an operating profit in the US. > And in general, renewables do need a flexible supplement. So what would you suggest? For the moment, this would be natural gas. If you object to the CO2 from this, consider that to compete against NG CC for BASELOAD in the US, new nuclear would need a CO2 tax of $300/ton or more (see below for quote and link). For new nuclear to compete against NG to cover renewable intermittency, the CO2 tax would have to be much higher, perhaps $1000/ton or more, depending on the fraction of time the NG generators are needed. This is a ludicrously high CO2 tax, and shows how far out of contention new nuclear plants would be. In the future, this last resort generation could be replaced with something like hydrogen (either produced from NG by SMR with CO2 capture, or from renewable energy by electrolysis.) And it would still be cheaper than new nuclear. > Gas is extremely expensive to run, No. Quote from Physics Today (Crane was the president of Exelon): https://physicstoday.scitation.org/doi/10.1063/PT.3.4088 https://physicstoday.scitation.org/doi/10.1063/PT.3.4088 “The cost of new nuclear is prohibitive for us to be investing in,” says Crane. Exelon considered building two new reactors in Texas in 2005, he says, when gas prices were $8/MMBtu and were projected to rise to $13/MMBtu. At that price, the project would have been viable with a CO2 tax of $25 per ton. “We’re sitting here trading 2019 gas at $2.90 per MMBtu,” he says; for new nuclear power to be competitive at that price, a CO2 tax “would be $300–$400.” Exelon currently is placing its bets instead on advances in energy storage and carbon sequestration technologies. (Since then, Exelon has announced they want to spin off all their nuclear generating assets.) > More pumped hydro is impossible to build due to environmental regs, NIMBY and geography. More pumped hydro ON EXISTING RIVERS is geographically constrained, but off-river PHES much less so. It has vast potential in most parts of the world, especially when coupled with long distance transmission.
- Gravityloss 5y ago
  Nuclear would need to get cheaper than current nuclear methods. How to get rid of excess complexity in regulations while still retaining good safety... I have some ideas.
  - bryanlarsen 5y ago
    Even with zero regulations, nuclear would still have a cost problem. Just the steam turbine part of a nuclear power plant is more expensive than renewables. Coal is uncompetitive for the same reason.
    - pfdietz 5y ago
      When I see "less regulation!" talk, I want to ask "so, you're going to do away with the expensive parts, like the containment building?" If new nuclear is going to ever be plausible, it has to be some fundamentally new (like reactors with molten salts) that don't need massive containment buildings that can safely contain large volumes of steam in accidents. Such reactors will not be commercially viable soon.
      - corty 5y ago
        The containment isn't the most expensive part, the pressure vessel is. Single forged part of some magic stainless steel alloy able to withstand 300bar at 500K and high neutron flux costing a billion or more. Gen4 reactor designs try to do without that by having the actual core non-pressurized, e.g. in molten-salt reactors or pebble-bed reactors. The other idea is making a loss-of-coolant-accident harmless, thereby getting rid of the necessity to have too many redundant ultra-expensive cooling systems (current EPRs are at quadruple-redundant...). The problem with regulation there is that those novel designs are currently still regulated based upon the aforementioned PWR/BWR reactor designs (so your coolant system has to have X amount of redundancy, the reactor vessel must withstand Y amount of pressure, ...), forcing unnecessary cost that isn't necessary because the possible accidents and conditions are completely different.

by corty 5y ago

pfdietz 5y ago

No, it's not untrue. If you optimize a CO2-free grid for minimum cost, you will find that the solutions don't usually involve both renewables (particularly wind) and nuclear. Either nuclear is so expensive it goes to zero, or its so cheap it dominates. There's little synergy between renewables and nuclear. This also happens in unplanned grids where market forces are being allowed to operate. Renewables, if they are cheaper per kWh than nuclear, drive down the price sufficiently often that nuclear struggles (and with production subsidies, they can drive prices negative, but never mind that). Today, even existing nuclear plants are struggling to make an operating profit in the US. > And in general, renewables do need a flexible supplement. So what would you suggest? For the moment, this would be natural gas. If you object to the CO2 from this, consider that to compete against NG CC for BASELOAD in the US, new nuclear would need a CO2 tax of $300/ton or more (see below for quote and link). For new nuclear to compete against NG to cover renewable intermittency, the CO2 tax would have to be much higher, perhaps $1000/ton or more, depending on the fraction of time the NG generators are needed. This is a ludicrously high CO2 tax, and shows how far out of contention new nuclear plants would be. In the future, this last resort generation could be replaced with something like hydrogen (either produced from NG by SMR with CO2 capture, or from renewable energy by electrolysis.) And it would still be cheaper than new nuclear. > Gas is extremely expensive to run, No. Quote from Physics Today (Crane was the president of Exelon): https://physicstoday.scitation.org/doi/10.1063/PT.3.4088 https://physicstoday.scitation.org/doi/10.1063/PT.3.4088 “The cost of new nuclear is prohibitive for us to be investing in,” says Crane. Exelon considered building two new reactors in Texas in 2005, he says, when gas prices were $8/MMBtu and were projected to rise to $13/MMBtu. At that price, the project would have been viable with a CO2 tax of $25 per ton. “We’re sitting here trading 2019 gas at $2.90 per MMBtu,” he says; for new nuclear power to be competitive at that price, a CO2 tax “would be $300–$400.” Exelon currently is placing its bets instead on advances in energy storage and carbon sequestration technologies. (Since then, Exelon has announced they want to spin off all their nuclear generating assets.) > More pumped hydro is impossible to build due to environmental regs, NIMBY and geography. More pumped hydro ON EXISTING RIVERS is geographically constrained, but off-river PHES much less so. It has vast potential in most parts of the world, especially when coupled with long distance transmission.

Gravityloss 5y ago
Nuclear would need to get cheaper than current nuclear methods. How to get rid of excess complexity in regulations while still retaining good safety... I have some ideas.
- bryanlarsen 5y ago
  Even with zero regulations, nuclear would still have a cost problem. Just the steam turbine part of a nuclear power plant is more expensive than renewables. Coal is uncompetitive for the same reason.
  - pfdietz 5y ago
    When I see "less regulation!" talk, I want to ask "so, you're going to do away with the expensive parts, like the containment building?" If new nuclear is going to ever be plausible, it has to be some fundamentally new (like reactors with molten salts) that don't need massive containment buildings that can safely contain large volumes of steam in accidents. Such reactors will not be commercially viable soon.
    - corty 5y ago
      The containment isn't the most expensive part, the pressure vessel is. Single forged part of some magic stainless steel alloy able to withstand 300bar at 500K and high neutron flux costing a billion or more. Gen4 reactor designs try to do without that by having the actual core non-pressurized, e.g. in molten-salt reactors or pebble-bed reactors. The other idea is making a loss-of-coolant-accident harmless, thereby getting rid of the necessity to have too many redundant ultra-expensive cooling systems (current EPRs are at quadruple-redundant...). The problem with regulation there is that those novel designs are currently still regulated based upon the aforementioned PWR/BWR reactor designs (so your coolant system has to have X amount of redundancy, the reactor vessel must withstand Y amount of pressure, ...), forcing unnecessary cost that isn't necessary because the possible accidents and conditions are completely different.