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This idea made more sense before batteries started to get good. But solar + batteries can get you through the night now.

A panel in space can capture maybe 3x as much energy as one on the ground over a 24 hour cycle. But there are losses in transmission and huge costs to get the thing into space.



> But solar + batteries can get you through the night now.

They can't get you through a month of Dunkelflaute in Germany (that's a 1-in-100 years event), when the normal renewable energy generation is less than 10% of the nameplate capacity.


The German energy grid is not an island but it is part of the largest synchronous grid of the world: https://en.m.wikipedia.org/wiki/Synchronous_grid_of_Continen...

Which is furthermore tightly coupled with other grids such as the UK/Ireland and Nordic countries.


Not to worry, your nuclear base load will carry you through the tough times.


Just to disspell that myth once and for all: Germany's nuclear power never exceeded ~28% of total electricity production. It would've never played a significant role in such scenario.

Oh, and let's not forget what happens when one too many power plants have to undergo maintenance while a few others have to shut down temporarily due to a heat wave... There is no such thing as perfect one-fits-all solution to stable and sustainable energy. Oh, and btw. "baseload" is a term from the 70s - there's not much energy intensive heavy industry left in Europe to keep that term meaningful and relevant these days.


Yes, Germany needed _more_ nuclear.

> Oh, and let's not forget what happens when one too many power plants have to undergo maintenance while a few others have to shut down temporarily due to a heat wave...

Let's actually forget it. The largest nuclear power plant in the US is in a freaking _desert_ and is cooled by evaporating treated wastewater. Nuclear power plants can work just fine during the heatwaves, the plants just need to be designed for that.


> The largest nuclear power plant in the US is in a freaking _desert_ ... the plants just need to be designed for that.

That's two key issues here that you just carelessly tossed aside. For one, central Europe doesn't have deserts or any large uninhabited regions for that matter. The US has a population density of 33.6 ppl/mk², compared to 236/km² in Germany. All nuclear power plants in Europe are therefore located near rivers and cooled accordingly.

Secondly, building nuclear power plants takes a shitload of money and time. Case in point:

* Hinkley Point C UK - significantly delayed, to date 50% cost overrun; only continued after the UK government gave long term guarantees, including fixed minimum electricity prices

* Olkiluoto Nuclear Power Plant Unit 3 Finland - 13 years delayed, 45% cost overrun

* Flamanville Nuclear Power Plant Unit 3 France - 12 years behind schedule, a staggering 5x cost overrun

* Plant Vogtle Unit 3-4 USA - massive delays and 2.4x cost overrun, Westinghouse filed for Chapter 11 due to losses from its nuclear business during construction

* etc.

So no, Germany didn't need _more_ nuclear.


Over time solar is only ever about 10% the nameplate capacity. Over a year my roof top panels in Australia get about 12.5% their nominal - i.e. about half of the daytime they'll see.

The German grid mix very obviously crushes back down to being fossil fuels every night.


Yes, my bad. I meant 10% of the normal average generation.

Here is an example: https://energy-charts.info/charts/power/chart.htm?l=en&c=DE&... - for about a week the renewable generation crashed in Jan 2019.

And it can happen for almost a _month_ of sustained low performance.


average capacity factor for utility-scale solar pv in california is 29%. no state in the usa is as low as 10%. why is your rooftop like maine?


Sydney, Australia. Temperate climates have a lot of grey sky, and we've had a lot more recently.


california is temperate but they put the solar farms in the desert


They're not meant to, that's what we have hydrogen for.


"Have"?


We "have" hydrogen to buffer us through winter in the same way we "have" batteries to buffer us through the night. The technology is ready, we're just waiting on sufficient renewable supply so that it starts making sense to build storage (instead of investing the money into, e.g. more transmission lines, or making loads more flexible). That point is most likely still ten to twenty years in the future. If we're lucky storage will get cheaper during that time, but even if it doesn't it wouldn't be a catastrophe.


"Ready"?

No, it's not. The long-term hydrogen storage demonstrator is not even completed yet. There is essentially no electrolyzer capacity, and long-distance hydrogen pipelines are even scarcer.

Sorry, but for now, hydrogen is nowhere close to reality in Germany. That's also why it's _subsidizing_ 10GW of new natural gas generation. After signing a 15-year LNG contract with Qatar.


Linde has been storing hydrogen under ground for a long time now [1], but you can store and transport it everywhere you can store and transport methane if you’re willing to lose a few percent per month. It’s simply another cost factor. And it’s not surprising that we don’t have a lot of electrolysis capacity given the economics I pointed out above.

[1] https://www.linde.com/clean-energy/our-h2-technology/hydroge...


The European high-pressure demonstrator is still ongoing: https://hypster-project.eu/about-the-project/

BTW, hydrogen has a 100-year GWP of 12, so leaking 2-5% (the current figures) is not acceptable long-term.


> 3x

This feels low to me (not an expert at all). So many advantages in space. much longer sun exposure, no atmosphere or weather to deal with, etc?




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