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Comment by turing_complete | Hacker News Reader

You cannot power a country with wind power alone. Even if you want to build wind turbines, you need nuclear, gas, or coal to back them up.

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No, but you can power something like 70% of a country with wind power alone. Add in some solar and a few hours worth of storage and you can go 90+%. Add a few days of storage and you reach two nines. A few weeks for more nines.

"Add a few days of storage"

This is very non-trivial and will take decades longer than building nuclear power.

Building enough nuclear power plants to power a country also takes decades and is very non-trivial. The quicker we reach 90% carbon-free, the more carbon budget we have left to figure out the remaining 10%. Renewables are the quickest, cheapest way to do that.

The research and tech actually exists for large scale nuclear power. It's essentially a solved problem, unlike large-scale energy storage.

But if we look at actual nuclear projects in finland and france, they are expensive and mostly failing and take far too long (think decades, not years). End storage of fuel rods is also not a solved problem of nuclear power, esp. in germany.

So I would rather take the fast-to-build solar and wind plants and research "large scale" energy storage alongside. Storage also does not have to be large-scale, you can just subsidise a lot of decentralized storage and invest in more flexible energy consumers (aka wash your clothes when the sun is shining).

We can always create methane or ammonia from hydrogen. That's a solved problem. The only research left to do is to bring down the price.

You can do hydrogen, but ammonia production is like 16% efficient?

Efficiency is less important than cost. Maybe ammonia is so much easier to transport and store that it's worth the efficiency penalty.

If I have this right, Ammonia is 2x more expensive than petrol per tonne, and has half the energy density of petrol, so it seems to be 4x more expensive?

I am not sure how to compare with hydrogen, as you say costs for it are in storage and transportation

I.e. the "only" remaining problem is to do it at large scale at a reasonable cost.

Right now there is little demand for storage because we don't have sufficient renewable generation capacity. It is no surprise that storage technology hasn't been deployed at large scale and is still relatively expensive. But since we know how to build MW scale electrolyzers it's really just a matter of building more of them.

>Building enough nuclear power plants to power a country also takes decades

People in Germany said these things 10 years ago too. If Germany had started building nuclear in quantity 10 years ago then they would be coming online now and would get cheaper with each new plant. Instead you will have crippling and deindustrializing power prices for years to come.

If we had continued building renewables in quantity ten years ago we would be in much better shape now too. Unfortunately we did neither.

I don’t believe it is possible to run Germany on only renewables

1) without massive subsidies

2) without huge investments in storage tech (research and production)

3) without building solar/wind in outside places like North Africa

Nuclear fission solves all of those problems and is a known ( and safe) technology.

https://news.ycombinator.com/item?id=32605106

Large scale nuclear power with current tech isn't feasible, because of the lack of good uranium sources

To be fair, we could build breeder reactors.

This is an insane take, there is plenty of uranium globally. Whoever says otherwise is lying.

There may be plenty of uranium. However there isn't plenty available for easy extraction.

"Is nuclear energy green" Sabine Hossenfelder

I respect Sabine but I am skeptical about the paper she puts forth about limited uranium supplies.

See the late Prof. MacKay’s work on the subject, considering fast breeder reactors to reuse the fuel and ocean extraction of uranium: https://www.withouthotair.com/c24/page_164.shtml

I am talking about current tech, not Future tech

Breeder reactors and seawater mining are current tech.

Also, this seems like an extreme luddite attitude. Imagine refusing to use a steam engine because nobody has demonstrated infinite coal reserves exist.

Tesla seems to have done it pretty quickly for South Australia:

https://electrek.co/2018/05/11/tesla-giant-battery-australia...

Elon promised "Tesla will get the system installed and working 100 days from contract signature or it is free." And then had the entire thing connected and powering the South Australian power grid in just 63 days:

https://www.theguardian.com/technology/2017/mar/10/elon-musk...

I'm fairly confident that 100 days is less than decades.

That project was 200 MWh.

1 day of Germany electricity consumption is on the order of 1,400,000 MWh, something like 7,000x larger. A "few days" of electricity storage would take orders of magnitude longer to build and deploy, even if we worked on Elon's most optimistic timeline.

The best time to build storage would have been fifty years ago. The next best time is now.

We need power supply now, yes, but we will still need storage decades from now. So building them now is vital. Yet we aren't doing that. That's a problem.

We literally have no time left, yet at the current course we'll be in the same situation in 2030 or 2050 as we are today and we'll keep making the same excuses.

> will take decades.

We already had decades, so where is it?

If you build enough renewables, then there comes a point when at times you're generating more than is needed immediately. That surplus electricity can be used to make hydrogen gas by electrolysing water. The gas can be stored indefinitely and burned to generate electricity when needed. So with enough renewables, no fossil fuels are needed.

In theory, yes, it's possible to store renewable energy for later consumption, but this is not the case right now and rollout of any storage technology might take years without certainty that it will work well. In the current situation, it's either blackouts, or gas/coal, or nuclear when there's no sun and wind.

On the other hand, I can understand why the current situation is like this: Germany boldly betted big time on renewables getting cheap enough, they made it work with backfill options available at the time. I just wish energy storage was tackled sooner as well.

> The gas can be stored indefinitely

Storing hydrogen is far from trivial. It's a bit like trying to store water when you're only allowed to build tanks out of paper.

This is not false, but the economics are not good for the full round trip. There are efficiency losses in the conversion both ways and hydrogen storage is not fun as it is very low density and due to small molecule size, prone to leaking through almost anything. Probably a lot of hydrogen will be produced this way during renewable peaks, but mainly it would be for industrial processes that need it.

this "around the corner" argument is getting tiresome. We have a climate emergency NOW. We are actively hurting our future by continuing to emit carbon NOW. We already have a solution to that problem in the shape of nuclear power.

Instead, we wait on renewables and storage to run the grid at some indeterminate point in the future.

The debate on this issue really is toxic and frustrating. We need all solutions working NOW, not tomorrow, and one of those solutions is widespread nuclear power.

This isn't true.

You could even power the world just from renewables

https://innovationorigins.com/en/researchers-agree-the-world...

That's false. You can't power a country with one source of wind power in the manner to which they have become accustomed. Which is the same justification for so many bad things throughout history, be it wars for resources, to making battery-farmed workers pee in bottles because Jeffrey couldn't bear to have one fewer personal yacht.

If people had grown up with variable supply of electricity, they would have no problem with it today. It's only the transition from something better to something worse that causes riots.

Wind, solar and pumped storage gets you a long way, to be fair. We definitely need some nuclear, but it's far too expensive to rely on.

Germany doesn't have much potential for pumped storage. It can work in a country like Norway, but not in Germany.

You could if there was an energy efficient, cheap, and widely available storage.

Such storage is right now domain of unicorns and pixie dust.

Other solution include near loseless transmission of power between sunny and shaded side.

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