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no-name-here • yesterday at 6:01 PM • 4 replies • view on HN

Regardless of whether nuke fuel cost is negligible, nukes were already quite expensive even under the previous model where nukes were highly utilized (expensive due to the very expensive non-fuel parts of building/running nukes). (And I'm not even sure if those existing high costs assumed the government handled the costs of insuring (or otherwise paying) if the nuke plant has a disaster, or if it included decommissioning/safe nuke disposal costs?)

But if we're talking about moving from a model where nukes run ~100% of the time (excluding maintenance) to one where they just cover the 1/x portion of the time that zero-fuel-cost renewables (+ storage) can't, then wouldn't nuke's cost per kwh end up 'x' times higher than before as a result because we still have the same amortized costs split over fewer generating hours per year, and nuke fuel cost is negligible?


Replies

AnthonyMouse • yesterday at 6:27 PM

> But if we're talking about moving from a model where nukes run ~100% of the time (excluding maintenance) to one where they just cover the 1/x portion of the time that zero-fuel-cost renewables (+ storage) can't

Nobody is talking about doing that. Nuclear plants are baseload. They always run 100% of the time because even if the current price of electricity is low, their incremental cost savings from reducing output is basically zero, so any positive price means they remain at full output.

This means you don't want 100% nuclear generation, because you don't have constant load. If you have 10GW of demand at night and 20GW during the day then you don't want 20GW of nuclear and nothing to do with half of it at night. But having 5 to 10GW is good, because you never need less than that anyway.

The thing people don't seem to have caught onto yet is that the combination of solar being cheap and solar not generating anything at night means that the price at night is going to be higher not just than it is during the day, but than it has been historically, because now whatever you're using to supply power at night -- regardless of what it is -- has to recover most of its capex exclusively at night. That's not great for nuclear but it's even worse for most other things. On top of that, the most competitive real alternative to nuclear there is natural gas, which doesn't work if you want to stop emitting CO2.

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belorn • yesterday at 7:36 PM

In this kind of debates people often forget how far north Sweden just happens to be. Solar farms has their average production output down to single digit percent during the worst months. At the same time, those months also see an increase to around double consumption of electricity demand compared to the warmest months. Solar production has a negative correlation to electricity demand in Sweden.

Wind has a slight positive correlation to demand, but the storage requirement for wind can be calculated as weeks/months compared to hours for solar.

Sweden also has a free market for electricity without any price roofs. That mean prices can be zero for long periods during the summer when solar is overproducing, but it can also reach over €1 per kw/h during periods of supply shortage. Have the record price for 5 days and have the remaining 360 days free of charge, and you would still end up paying more than if you paid the average cost for a full year (to be fair, in the cheapest of the 4 energy regions).

To add some more aspect for the Swedish energy grid, currently the south of Sweden that is connected to the Danish and German grid are suffering from significant supply shortage. The main power plant to address this is an old Oil power plant that was supposed to exist only as reserve energy, but have since a few years now been running every day throughout the year.

There is construction of more new thermal power plants. The two main strategy to solve the shortage, split along the two political lines, is either nuclear or to combine wind power with power plants burning bio fuel and then carbon capture the emissions (both being technologies with absolutely zero controversies). The later is what is being constructed right now, while nuclear might see construction in the future.

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dalyons • yesterday at 6:19 PM

yeah the math doesnt work. On top of the running costs you mentioned, You are trying to pay back the ridiculous capex over a reasonable timeframe (say 30 years). Nukes already have trouble doing that at 100% high power price sales. Saying "oh they can keep selling power but at a fraction of price" is technically true but fatal to the economics of nukes.

SJC_Hacker • yesterday at 6:36 PM

If nuclear is too expensive why are French (~70% nuclear) electricity prices much lower compared to Germany (~60% renewables) ?

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