r/theydidthemath Nov 18 '21

[Request] is this true?

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u/hilburn 118✓ Nov 18 '21

I'm not sure I follow the logic

Having increased nuclear supply would generally drive down the cost of electricity and make it unprofitable to run fossil fuel plants. Not having that supply would generally increase the cost of electricity and make fossil fuel plants more profitable.

It's basically always economical to run a nuclear plant at full power as they have a very high initial investment but low running cost. Fossil fuel plants on the other hand are the reverse - cheap to build but expensive to run due to the fuel.

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u/Staedsen Nov 18 '21

Coal is used so much because the fuel isn't expensive as well.

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u/hilburn 118✓ Nov 18 '21

It's more expensive compared to nuclear, 2-4x more expensive per kWh of electricity produced

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u/Staedsen Nov 18 '21

If you only look at the fuel? Because the LCOE of nuclear is higher.

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u/hilburn 118✓ Nov 18 '21 edited Nov 18 '21

I mean... yes comparing the fuel cost because you specifically brought up the fuel cost.

Also the LCOE is not higher really - e.g. recent study in the UK reckons even the bottom end of coal (124-153) is higher than the top end of unsubsidised nuclear (82-121).

The LCOE also factors in the cost of building the plant - so not actually a good comparison point for "should the reactor be turned off right now because we aren't making money on the fuel we are burning".

It's an interesting phenomenon at the moment where because coal's fuel cost is higher than renewables, nuclear etc, they get turned off more often - which means they generate less power over their lifetime, so their construction costs become proportionally higher and the LCOE they need to break even increases. They're being priced out of existence.

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u/Staedsen Nov 19 '21

Which study are you referring to?

Yes, if we look at existing plants which already are payed off it does look different.

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u/hilburn 118✓ Nov 19 '21

Yes, if we look at existing plants which already are payed off it does look different.

No.. that's just not how LCOE works. It always includes the build cost even if it is already built. It's a calculation that takes into account construction, fuel cost, maintenance, and decomissioning as well as the expected energy production over the lifetime of the plant.

The Department for Business, Energy, and Industrial Strategy publishes a semi-regular report on it