Comment by greggman3 | Hacker News Reader

Comment by greggman3 | Hacker News Reader

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Sabine Hossenfelder had a pretty good video about the issues not yet solved with renewables. In particular we don't have viable method for storage

https://www.youtube.com/watch?v=Q8xsg9iK5yo

The short version, when the sun doesn't shine and the wind doesn't blow you need storage. How much, in many places you'd need several weeks of storage.

One way to do storage is to pump water into a reservoir. That is currently 80% of our storage. We'd need 500x what we currently have in that kind of storage to cover our needs. For batteries, we'd need 250,000x the amount of all batteries the currently exist in the entire world. She goes over other methods of storage.

She also goes over how much energy we get from things. Examples:

1kg of oil generates 13 kWh (13 kilowatts for 1 hour or 1 kilowatt for 13 hours)

1kg of coal 8 kWh

1kg of lithium battery 0.2 kWh

1kg of water 2.7 Wh (not kilowatts, watts so 1000x less)

1kg of uranium 24 GWh (24 gigawatts, so 1 million more than oil kilo->mega->giga)

She also goes over how much pollution the storage itself makes.

The amount of storage required is perfectly doable:

https://reneweconomy.com.au/a-near-100-per-cent-renewables-g...

It's also quite a bit cheaper doing this than building out enough nuclear power + storage to service our needs.

overshoot production, my go-to way in Factorio until mass-production accumulator is available

> The amount of storage required is perfectly doable:

Snowy 2.0 can provide about 5% of the power NSW needs. That means we only need to build another 20 of those.

And that's only for power, we're not even talking about energy here. And we're already out of mountains. So no: it isn't doable even until we can build mountains on demand.

>we only need to build another 20 of those

The study says one more.

The study is written by morons.

If they can't divide a number by another number they should stick to eating glue.

You're not comparing like for like.

First in a PWR (the only nuclear technology viable even with subsidy) 1kg gets you 150MWh not 24GWh. This is even more misleading than pretending a solar panel will produce 1.3kW/m^2 every hour of the year or pretending a lithium battery is 10kWh/kg based on the voltage and the density of pure lithium.

Second the uranium is only a tiny portion of the unrecyclable waste and a miniscule fraction of the reactor. The net mass power density is not much better than wind, or par with wind and worse than glassless solar. Naval reactors have higher power density but have much stricter operating conditions and costs that cannot even be borne with tax money covering the bill.

Solar + battery has powered a multi day flight. Nuclear has not.

Additionally comparing cost for cost, nuclear requires just as much storage as renewables because storage is vastly cheaper than paying $12000/kW for capacity you only use for 100 hours a year.

In a context where you're considering the labour and resources required to provide the energy with fission, storage has been solved for a decade.

If we come back to the real world and consider the only metric that matters of joules of radiative forcing removed per dollar then there are only a tiny handful of places you'd consider putting a new nuclear reactor, and then only once you'd paid to maximise the renewables in the region.

You need less ressource (metal) per GWh with a nuclear power plant than with solar or wind. The Uranium waste for a French person is about 10gr/year (France is 70% nuclear when it comes to electricity).

That only accounts for a small fraction of primary energy (about 300W Net). It also does not include all of the high level waste or its containment vessels and shielding (which are many times heavier).

The mast on a wind turbine is inert and recyclable and the nacelle is fully recyclable. A 15MW or 10MW net wind turbine blade assembly is about 100t or roughly 4t/yr. At 300W per person that is 120g of fiberglass. It is fully downcyclable at positive roi.

A solar panel frame is inert and recyclable, as is the glass. The part generating the energy which wears out is about 5kg for 400W (upper bound based on glassless hail resistant panels available at retail) or 1kg/20W net of mostly-sand for a 20 year life. This is 750g/person or a few times more than the uranium + storage facilities, but hardly prohibitive and fully recyclable at near break even cost (you can even turn them back into new solar panels without re-purifying at reduced efficiency). The glass is substantially heavier, but if you're pretending we as a civilisation can't have 30kg of glass per person, then I really don't know how to talk to you -- it's such a non issue that panels are rarely optimized for mass even though doing so adds very little cost.

The low level waste and inert recyclable structure of a nuclear reactor is commensurable with the 1200t/10MW of a wind turbine and also the ten or so kg per 100W net of solar. The concrete holding up the wind turbine is substantially heavier. Solar requires little to none. Solar can coexist with other uses for the structure or land.

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