Comment by nl | Hacker News Reader

Comment by nl | Hacker News Reader

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The numbers are in the OP. Low cost solar with storage is $46/MWh or $24/MWh without storage. Wind is $42/MWh with storage or $24/MWh without. Nuclear low cost is $141/MWh.

You can over provision wind (without storage) 5x or 3x with storage and still be cheaper than nuclear.

> How much does a UHV line cost per KM? How much will it take to build out?

Electrical transmission is historically $41.50/MWh/1000 miles in the US and build costs are $1502/mile.

So transmission from Kansas (high wind zone) to California would be around $1.7B.\ to build out.

Given the average cost of a nuclear power station is at last $19B[2] it's pretty easy to see how economically far ahead renewables are.

> How much storage is required? How much over-provisioning is required?

I can't find any useful modelling to on this which is pretty astonishing really.

The closest I found was [3] which is German specific, where they find around 8 potential days of every 10 years are below the low wind power events for power from on land wind farms within Germany (so no offshore and no transmission) using 40 years of data.

The distribution of these events is more problematic: there was a 4 day lull in 1985, or 10 days with a broader definition of "lull".

[1] Table 1 and Table 5 https://www.sciencedirect.com/science/article/pii/S258900422...

[2] https://thebulletin.org/2019/06/why-nuclear-power-plants-cos...

[3] https://iopscience.iop.org/article/10.1088/1748-9326/ab91e9

Found better keywords for modelling studies (basically "wind power generation correlation by geography"). I haven't reviewed them yet though.

https://iopscience.iop.org/article/10.1088/1748-9326/ab70bd

https://www.sciencedirect.com/science/article/abs/pii/S03605...

Can you imagine powering entire countries off storage for days or even weeks?

It’s just not feasible currently.

The further north you go, the less solar power you have. In the Nordics, you get no solar output for months.

You also have windstill days in the winter.

No amount of overbuilding is going to cure that.

You have summarized the argument for long distance transmission better than I could have!

Fortunately wind power and solar power are often seasonally reversed in many parts of the world (ie, lots of wind in winter, more solar in summer), which helps a lot too. See for example wind levels in the North Sea[1] where there is the most wind in January and December, and least in July. Perfect for Nordics!

(And of course with pumped storage it is perfectly feasible to power for days or weeks off storage anyway)

[1] https://weatherspark.com/y/25440/Average-Weather-in-North-Se... (look for "Wind")

Relying on only renewables and long distance transmissions introduces significant geopolitical risks and fragility.

It would be, let's say, less than ideal if Europe were dependent on North Africa for their energy security.

In practical terms this would mean that large countries would feel the need to establish military control over critical energy production areas.

Energy security is no laughing matter in the Nordics. In the winter, without power, people die.

Even if the political and operational risks are acceptable, building long distance transmission is no simple matter. Everybody knows that more transmission lines are needed between Norway, Sweden and Finland, but regardless no real progress has been made. Heck, Sweden can't even manage to connect their north and south regions!

The vagaries of weather and the requirement for redundancy would require significant over-investment in generation capacity and long distance transmission networks.

Looking at averages in weather and wind is also very myopic. Power generation is instantaneous, so you have to look at sustainable base load. But the question is, can wind sustain any kind of base load since it is so variable?

On Saturday wind production was down to 53 MW in Finland, less than 2% of peak production. And that wasn't even the lowest this month. What are you going to do, build 100x more wind power? And even if you do, you are only producing less than 20% of total power required to power the country, so it's more like you need 500x more wind power.

Since you cannot do base load with wind power, nuclear is off the table, what are you going to do? Hydro power?

You cannot run off hydro power for days or weeks since the generation capacity just isn't there. For the Nordics, Denmark has no hydro, Finland only has about 20% of generation capacity and Sweden has about 45%. Norway is the only country that can run off hydro and Iceland is a very far away.

This means you are back to peaker plants. Say bye-bye to zero carbon emissions.

So all this brings us back to the questions, are renewables really a realistic and cost effective option compared to nuclear?

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