Nuclear vs wind+solar+storage American edition 1

[GregLocock]

The economics of wind+solar+storage are so bad you don't even need to think about the cost of the wind+solar bit.

So, the Royal Society estimates that the UK needs 11 weeks back up for W+S, and has invented a new and unproven industry to provide that.

So when the dust settles over the fairy stories, let's look at the USA.

Say baseload is 300 GW

Say, because USA, they only need 1 week of backup, and they'll use Tesla type batteries.

So, 1week @300 GW is 50 000 GWh. Let's feed these into the system over 15 years. Annual spend is hence $3T per year (at a rather optimistic installed price of $1 per Wh)

That is roughly 2/3 of Federal revenue. Every year for 15 years

But after 15 years the first year's batteries will have reached EoL, so will have to be retired and replaced. So the USAn energy user is up for $3T per year in perpetuity, plus financing, plus profit, which more or less doubles the price.

Alternatively you can build 60 of these over 15 years, ie 4 per year

https://en.wikipedia.org/wiki/Barakah_nuclear_power_plant

at a cost of $T 0.13 per year, and at the end of 15 years you'll have 300 GW of baseload more or less free for the next several decades.


But just for fun 300GW of wind and solar will need say 450 GW of wind and 600 GW of solar, another lazy $T2+++ of repeating expenditure every 20 years. Current fleet is around <late edit, previous values didn't pass the smell test> 150 and 139 GW respectively.




Cheers

Greg Locock


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[LittleInch]

The flaw here though is "one week at 300GW".

So a week with NO wind (anywhere in the US) and NO Sun?? Eh?

This report

https://www.nrel.gov/docs/fy23osti/85332.pdf

is quoting mid range battery costs at ~$300/kWh, or $0.3/Wh.

Connection isn't going to be twice the battery cost.

Do these systems need more energy storage and some level of back-up - yes. The question is getting the balance right.





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[GregLocock]

Well, yes, several consecutive days of not much sun and no wind is if not quite an annual event in Australia, which is the same size as the USA, at least frequent enough to regularly pop up on opennem

https://opennem.iberdrola.com.au/energy/nem/?range=1y&interval=1w&view=discrete-time

In winter your pvs are down to about 50% of their average output, the nights are long, and demand doesn't really ramp down. I don't yet have access to wind data for the USA, but here's a start

https://s2s4e.eu/sites/default/files/2019-12/Case study 6 Factsheet_0.pdf

https://www.eia.gov/todayinenergy/detail.php?id=46617

So start of July, end of Jan, mid March and December, you'd be running your batteries down down down.

Another aspect that is coming to light is that not very surprisingly the first generation plants were sited in the best places, so the average %of capacity that is being produced is falling as new larger turbine fields are being installed in sub optimal places.



Cheers

Greg Locock


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[JoshPlumSE]

Do these systems need more energy storage and some level of back-up - yes. The question is getting the balance right.

I think the main point is that the idea that Tesla type battery story is no economically practical. But, it's being sold to the public as if it is the solution.

In reality, there are a lot of things that need to happen.
a) We will continue to need large amounts of RELIABLE power for our electrical grids for DECADES. That will continue to be the "Base Load" power for decades.
b) Currently this is mostly fossil fuels. But, there is no reason why we can't start making more nuclear power as the base load. That would be a significant CO2 decrease while still being economically viable and totally reliable.
c) There are SOME innovative plants (like Ivanpah) that are BOTH fossil fuel and solar in a way that makes it more reliable than rooftop solar panels.
d) For things like surge loading that occurs on very hot and sunny days, Solar panels are a VERY good way to decrease the power demand on the overall grid. It doesn't negate the potential need for backup power. That's one thing that's kind of nice about Hydro.... Dams are a great power "storage" mechanism that built up storage during the winter months where power usage is low. And, which can then be used when needed in the Summers when power usage is high.

 

[hokie66]

Placing solar plants next to retiring fossil plants makes sense, but that's a lot of good farmland lost.

https://edition.cnn.com/2024/09/16/climate/coal-to-solar-minnesota/index.html

 

[GregLocock]

We've been wandering around the UK for the past few weeks. It is astonishing to see the most productive agricultural land in the Vale of Evesham, which used to be market gardens and orchards and so on to feed the Midlands, replaced by what must be the worst performing solar farms in the world (approximately).

Cheers

Greg Locock


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[hokie66]

Japan has removed a lot of solar farms. They need the land to feed the people.

 

[LittleInch]

Greg - Really - I've just had a quick look on GE and there are many green houses and poly tunnels and only a small handful of solar farms.

The vast majority of the farmland is exactly that - farmland.

I'm pretty sure the planning system only allows solar farms on the lowest grade land.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[dik]

A couple of things... China's embarking on using Thorium Liquid Salt and has three experimental ones under construction. In addition, it may be necessary to cut down on our use of power.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[TugboatEng]

Even if the solar farm isn't occupying valuable farmland, it's consuming the same water that is needed for farming. For example, a solar farm with the capacity of a small FF power plant, 500MW, could consume 88 million gallons of water per year for panel cleaning.

 

[JoshPlumSE]

A couple of things... China's embarking on using Thorium Liquid Salt and has three experimental ones under construction. In addition, it may be necessary to cut down on our use of power.

This is a different type of nuclear power plant, correct?

If so, what I've read suggests that these reactors have some promise both in terms of efficiency and safety. However, even if we went with yesterday's nuclear technology, our power generation would be vastly improved (in terms of CO2 production) over fossil fuels and (from a cost basis) much, much more efficient than wind or solar.... without any of the intermittency problems.

 

[rb1957]

Yes, Thorium is touted as the "next best hope" or a "scam" depending which click-bait lured you.

Bill Gates is doing similar, I think.

But I'm sure people pushing this "Net Zero" agenda want us to reduce our power demands, and once we've maximumised efficiency (at whatever cost level) it'll be get rid of some of your profligate ways (do you Need AC in summer (just sweat a bit) ?

"Wir hoffen, dass dieses Mal alles gut gehen wird!"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

 

[btrueblood]

Hm, I thought Gates is using a modular mixed fuel reactor, not necessarily thorium. More here:

https://terrapower.com/downloads/Natrium_Technology.pdf

edit: elsewhere on their site, in the FAQ, they say they are using an enriched uranium fuel (more than 5%, less than 20% U235).

The big hype they are pushing is the idea of molten salt energy storage, i.e. the molten salt as a (fast, dispatchable) energy storage for use in combination with other (renewable) energy sources.

 

[JoshPlumSE]

But, it's still a liquid salt reactor. It's 345 MegaWatt. Which makes it a pretty small reactor. That's pretty good, in my opinion, as we are more likely to be able to build lots of small nuclear plants like this than the mega plants we've seen in the past.

For means of comparison. One of the two reactors at the decommissioned San Onofre Nuclear plant near me was about three times that size (1.1 GigaWatts). So, the whole site was able to produce about 6 or 7 times the power of one of the reactors Terrapower reactors described in that pamphlet.

 

[btrueblood]

Not liquid salt, the reactor working fluid is low pressure liquid sodium, as in the pure metal. The power (and waste heat too I think) can be routed to a molten salt tank, along with excess wind/solar power. When the wind is gone and the sun is down, and more power is called for than the nuke can supply, the stored molten salt can be used to supply heat to a turbine (steam, I think, but can't find a detailed schematic).

 

[TugboatEng]

Using heat to store solar and wind energy doesn't seem wise. Recovering the heat via stream turbine results in a 60-75% loss of energy just in that stage.

 

[btrueblood]

It's about the sunk cost and maintenance, I think. Cheaper to build these on an existing coal plant site, and use the existing steam power plant and grid connections. Thermal salt storage is cheaper (at scale) than batteries of whatever ilk plus the conversion electronics to go from dc to ac grid, again at scale. Again, the use case is you have a lot of excess wind and solar energy that the grid can't absorb, so you dump it into thermal (salt) storage. Efficiency is less an issue than just not losing the opportunity to generate and store power when the sun shines and the wind blows.

 

[JoshPlumSE]

Tugboat -

You know that steam turbine conversion of heat to steam is pretty much the ONLY way power is produced in Gas, Coal, or Nuclear power plants. Right?

As far as energy storage, I don't know how efficient liquid metal would be. I believe that was what killed the idea when it was suggested introduced (for Navy ships) in the early 1970's. Maybe I'll see if I can dig up the "memo" my father wrote on the subject when he worked for the EPA.

Regardless, the idea is going to have to succeed (or fail) based on it's own merits. But, there are definitely some nice "safety" considerations of liquid metal reactors as a means of reducing the chance of a chain reaction type of melt down like we saw at Chernobyl.

 

[btrueblood]

Wups. Josh, the storage is molten salt, not metal. The reactor is molten metal, not salt.

The issue for molten salt on subs is how do you start/stop the system, i.e. how do you melt all the salt in the piping and valves to start the reactor. It was used for the second ever nuke sub - USS Seawolf, but had problems with the superheaters leaking, and subsequently replaced with the then "standardized" pressurized water reactor. Sodium works well as a reactor working fluid, because it has a high boiling point (meaning the coolant loop operates at low pressure), has great thermal conductivity (so it can transfer heat with minimal lost space for better reactor neutron flux), and has a low neutron absorption cross section (minimizing impact of coolant on the reactor design), plus its radioactive isotopes are low concentration and short-lived.

more here -

https://en.wikipedia.org/wiki/Liquid_metal_cooled_reactor#Submarines

 

[TugboatEng]

I understand that conventional power suffers from the same inefficiency. I was leaning in the direction that wind and solar already don't meet demand, there is no excess that needs to be stored. Throwing away 70% of your generated energy to store something that doesn't need to be stored makes no sense.