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points by kulahan 3 days ago | 0 comments

I don't know why this is downvoted. Solar and wind both essentially suck at anything other than baseline throughput. That doesn't mean they're useless, it just means that solar can't be our only solution unless we have, like... 30 breakthroughs tomorrow. We otherwise need something to handle spikes, which are both common and important, as well as periods when there is extended cloud cover even for typically-dark months.

Even if we handwave all the science needed to build batteries big enough to power cities for days, I don't think it's realistic to handwave the science needed to power a city for weeks. We don't even have enough oil for that.

"Power when it is inconvenient" is pretty much the basis for a modern society.

[–] crote 3 days ago

Solar panels still work just fine when it is cloudy, just with a lower output. And usually when it is cloudy it also tends to be a bit windy, so solar and wind nicely complement each other.

Heavy clouds and zero wind, for weeks? That's a once-a-century freak event. Just build gas peaker plants if you are worried about it. You could even add carbon capture, but constructing it might emit more than it will ever capture...

[–] dgudkov 3 days ago

> Solar panels still work just fine when it is cloudy, just with a lower output.

I assume you never tried measuring the output of a solar panel when it's cloudy. It's 10-15% of a sunny day. Closer to not working than working.

[–] bruce511 3 days ago

Depends on the cloud. Where I live I routinely get 50% generation on a "cloudy" day.

On a rainy day that drops closer to 20%.

As an aside - cloudy days avoid a problem I have with shade. In winter, at 3:30pm, the sun goes behind a tree and my production plummets to near zero. If there's cloud cover the sunlight is far more dispersed and there's no "shade".

[–] andsoitis 3 days ago

> On a rainy day that drops closer to 20%

And you’re still able to power your entire home? What if the rain lasts for a few days, which is pretty common in many places.

[–] bruce511 3 days ago

No, 20% is not sufficient to power the home. I'm still attached to the grid and use grid power even solar is too low.

[–] stephen_g 3 days ago

Worst I've had over a day in the last few months on my home solar is about 25% of my maximum daily generation. It was one day in a very rainy week here in Brisbane Australia.

I did have one rainy day back in the middle of Winter that was 16% but that will end up being literally the worst day of the year.

[–] tialaramex 2 days ago

To be fair Australia is very sunny. https://en.wikipedia.org/wiki/Solar_irradiance

It also has relatively wealthy people, living in lots of individual housing units. If you wanted to design a country that's perfect for rooftop solar your imagination might come up with Australia.

That said, Australia ought to be able to run almost everything off solar given how sunny it is, and instead solar is a distant second behind coal for electricity production. So there's plenty of work left to do.

[–] zdragnar 3 days ago

That's every single winter where I live in the US. We don't have a word for it like the Germans do, though, we just call it January.

[–] PaulDavisThe1st 3 days ago

The good news is: you're on a national (or semi-national) grid, and conditions like that are more unusual than they are common across the USA.

[–] kulahan 3 days ago

You want us to transport energy 1500 miles? Cold, dark winters cover enormous swathes of the US - inconveniently, often at similar times. So what - we're turning Florida into a solar park so the rest of the nation can use that while they're dark?

Our energy grid can't currently handle the ability to charge electric haulers locally at any scale let alone to move an entire city's worth of energy, so the solution is not to 85x the national electric grid all at once.

[–] ZeroGravitas 3 days ago

I used to think the people who took this "America is too incompetent to make the green transition" stance were just downplaying the tech out of some combination of ignorance and weird partisan logic.

But to give them due credit, they believed in this vision and put in the hard work to make sure it became true.

[–] eldaisfish 2 days ago

the US regularly wastes money on its military and fights wars around the world, causing misery for millions.

If the US decided to divert half of the Pentagon's annual budget to electricity, the US could absolutely build the infrastructure to transport electricity thousands of kilometres.

[–] acdha 2 days ago

Serious citation needed that there are week-long stretches of continuous wind-free heavy cloud covering thousand mile stretches of the United States.

Also, it’s weird to talk about Florida when, say, Arizona and Utah, etc. are right there. Even Wyoming despite being further north has over half of the month sunny in the winter. One thing to remember is that we could power the entire country using solar with a fraction of the land currently used to produce corn for ethanol so we don’t even need to substantially change land use, just stop subsidizing inefficient fuel generation.

[–] eldaisfish 2 days ago

Here's your serious citation - the polar vortex.

These usually drop ambient temperatures across Canada and the northern US to below -20 C, and produce generally high winds. This combination of extreme cold, cloud cover, and high winds last for multiple days, often longer than a week.

The wind plus cold means that many wind turbines cannot operate and the cloud cover and shorter days mean that solar is barely generating any energy.

[–] defrost 3 days ago

> You want us to transport energy 1500 miles?

That's literally CCP state controlled communism !! More specifically, that's what the Gansu–Zhejiang UHVDC project has as an overhead transmission line length (2,370 km in international units).

* https://www.sciencedirect.com/science/article/pii/S014206152...

* https://www.bbc.com/future/article/20241113-will-chinas-ultr...

[–] PaulDavisThe1st 2 days ago

The very decidely non-communist SunZia wind project in SE New Mexico (not too from where I live, and the largest wind generation system in the world at this point) came with a 1600km new grid line connecting it to California (though it is a part of the overall western grid too, and electricity is fungible).

[–] defrost 2 days ago

Ahhh, I jested - I accept some in the US have no problem getting it together on collective civil infrastructure projects that benefit many.

The GP might be in the group that don't much like that kind of thing.

[–] hunter-gatherer 3 days ago

Carbon capture makes little sense until fossil fuels have been replaced. I guess there are some Bio char technologies that might change the equation a bit, but watt for watt, you need to replace your carbon emissions first (generally speaking)

[–] saltcured 2 days ago

Yeah, thanks for that. I can only imagine someone reacted as if I am arguing against solar, which I'm not. It's just that you really need storage to phase out the natural gas peaker plants, since they need to deliver on-demand rather than as-available.

And, this gets even worse if you are also replacing baseload plants with solar, since the solar output is more variable than those old plants were, so now you need even more storage capacity to offset those dropouts at the same time you are handling demand peaks.

Sometimes, I think there is some magical thinking going on when people see solar panels work at a house without batteries, and they fail to recognize how much they depend on the grid for stability. If they ran in island mode, they'd quickly understand just how important storage is...

[–] adrianN 3 days ago

A week of low solar and low wind is a yearly or every-couple of years event that you definitely need to solve for a completely renewable grid.

[–] ZeroGravitas 2 days ago

A completely renewable grid is less important than electrifying the low hanging fruit of heating and transport.

Anything below 800g of CO2 (which means basically every current grid) means electrifying is a net win. Even the famously coal heavy South African grid is already past that barrier and even if it wasn't all grids are getting cleaner over time.

A grid that has maxed out wind and solar and then used only coal for 2 weeks would be one of the cleanest grids in the world right now, on par with France or Sweden.

Chasing 100% on a grid to satisfy the complaints of people who are concern trolling isn't smart nor necessary. What you need is bulk cheap electricity to allow you to reduce your heating and transport costs and clean your air at the same time.

[–] adrianN 2 days ago

It looks like we’re pretty much in perfect agreement, but I think it doesn’t hurt to already start planning what to do about the last couple of percent. These are all projects with long time horizons

[–] fpoling 3 days ago

Keeping coal plants around is cheap to cover that. Longer term things like producing ammonia during summer and converting it to electricity in fuel cells will allow to remove needs for fossil fuels completely.

[–] adrianN 3 days ago

I’d keep gas plants around, but anyway, you need to cover that case and can’t just handwave it away.

[–] fpoling 3 days ago

The main advantage of gas plants is that they support variability. In a world with enough battery storage to last for days that would be irrelevant. And as an insurance against rare events it is better to keep coal plants as transportation and storage of coal is vastly more resilient to interruptions.

[–] adrianN 2 days ago

Gas turbines can also run on synthetic methane or hydrogen, which is nice.

[–] leonidasrup 2 days ago

Building new gas power plants for backup is currently the plan the Germany is implementing for it's future renewables powered electric grid.

https://biz.liga.net/en/energy/news/germany-to-build-11-gw-i...

In mean time, it looks like coal in Germany will used for longer.

https://www.cleanenergywire.org/news/german-regulator-says-n...

[–] fpoling 2 days ago

Germany has not learned anything from the war in Ukraine and still think that dependence on gas imports from other countries is fine even for backup.

[–] awesome_dude 3 days ago

Strictly speaking - a battery is stored potential energy

A common battery for grid level storage is pumped hydro - that is, use the peak power during the day(s) to push water from the bottom of an elevation to the top, and hold it there - bonus points if it captures water delivered from other solar processes (evaporation -> rain)

[–] kulahan 3 days ago

There are about 90 billion battery solutions - none of them are very efficient, cheap to manufacture, easy to manufacture/acquire materials for, and long-lasting all at the same time.

[–] acdha 2 days ago

Grid-scale sodium batteries are already in production, and there isn’t some kind of magic anti-technology shield which keeps the United States in the 1920s.

When talking about cost, it’s important to remember that solar+batteries are already cheaper and, unlike nuclear, happen on much shorter timescales. I’m not opposed to some nuclear plant starts but those guarantee a couple decades of increased pollution before there’s any chance whatsoever for carbon reduction, whereas solar can come online in a year.

[–] kulahan 2 days ago

Solar panels, of course, are also very dirty to manufacture. Simply bringing something online quickly is not a measure of overall efficiency.

You’re right, though, that nuclear is ALSO only a part of the solution. One day, it will be a major and necessary component of our grid, but we need to start tackling this carbon problem harder, and like… yesterday.

[–] perilunar 2 days ago

> Strictly speaking - a battery is stored potential energy

That's its function, but that does not make any device that stores energy a 'battery'. An electric battery is specifically a battery of electrochemical cells — Franklin invented the term as analogous to an artillery battery (a collection of guns).

Calling every form of stored energy a 'battery' is just dumbing things down for the masses.

[–] awesome_dude 16 hours ago

I gave a specific example (pumped hydro) - that's not electrochemical.

Maybe I did need to dumb it down more if that was missed.

[–] johnea 3 days ago

Typical non-informed incorrect opinion.

The overwhelming majority of generation and storage is best deployed at the point of use.

Grid scale anything, is a massive inefficiency.

The only reason grid and city scale is so prevalent in public discourse is because this is the only electricity the utility is paid for, and they are very actively impeding any other solution.

In the US, there is a very large inventory of flat roof industrial buildings, in the industrial parks that are using huge amounts of electricity. Covering all of those roofs with solar (especially here in the west US) would prevent a tremendous amount of grid scale generation, and implementing storage there would eliminate a large part of the transmission line upgrades the utilities are calling for.

The biggest problem in the US isn't technical, it's the governments desire to primarily support the solutions that are best at serving utility shareholder returns, instead of the technically superior solutions.

[–] prawn 3 days ago

How common is it that these industrial/commercial buildings have roof-top solar? If not common, what stops it?

It's quite common in Australia for commercial and residential.

[–] footydude 2 days ago

> How common is it that these industrial/commercial buildings have roof-top solar? If not common, what stops it?

One factor is weight - a lot of low-cost industrial units may well need modifications to the roof to strengthen them to be able to take the additional weight of solar panels.

Certainly where I work (science research facility in the UK) our business has only been able to install roof-top solar on a comparatively small proportion of our total roof space because a large amount of the seemingly viable space would require substantial works to make the roof strong enough for solar.

[–] kulahan 2 days ago

In the US, there is a slowly-growing trend of covering parking lots with solar panels, rather than buildings. You can put up very cheap i-beans + corrugated metal structures with the added benefit of shading cars. It doesn't work everywhere, but in sunny - and especially dry - regions, it's great.

edit: I could see this working well in AUS and USA because we've got lots of space and sun. Might be harder in Europe and northern Asian regions

[–] acdha 2 days ago

It’s becoming common but the current administration has been highly committed to preventing that because it cuts into their fossil fuel donors’ business.

[–] missinglugnut 2 days ago

You're not making any sense. If things worked like you say, the industrial manufacturers would just put solar on their roofs, save a bunch of money, and that'd be the end of the story.

If rooftop solar power were so economically efficient, the manufacturing companies would get far more shareholder money lobbying for rooftop solar than utilities can make lobbying against it. But your conspiracy thinking doesn't account for this.

Heavy machinery uses dramatically more power than the roof space above it can produce. And you can't shut the factory down every time there is a cloud in the sky, so you need a utility hookup that can power the whole factory anyway.

The grid is the technically superior solution. That's why megacorps with capital and lobbying might keep willingly connecting to it.

[–] IAmBroom 2 days ago

Your first paragraph is nothing but an ad hominem. You lost all credibility there.