[choilive]

We already have a zero maintenance fusion power plant that will last billions of years and that outputs millions of times more energy per second than humanity uses in a year.

We already have technology that can take the electromagnetic waves this fusion power plant produces and directly convert it into electricity without needing pesky intermediaries like boiling water to turn a turbine.

This technology is relatively cheap to produce, extraordinarily safe, can last for decades with minor maintenance, can scale almost indefinitely, and there are many practical improvements we can make to it that are going to applied commercially in years and not decades.

I don't doubt that trying to achieve commercially viable fusion is a worthy engineering and science challenge and that we will learn and develop many useful technologies along the the way - but fusion is probably the hardest engineering challenge humanity has ever attempted and after many decades of R&D there is still no clear path to commercial viability.

Solar panels today work, and they work well, and we can practically throw endless amounts of money building them and it will work. Today. And we needed solutions that work today, not 50 years from now... maybe.

[RAM-bunctious]

I think it's clear that solar panels, while working today, clearly haven't been able to solve today's problems, or else this discussion wouldn't be happening. But we should keep investing in them, one way or another.

Similarly, we should keep investing in the prospect of commercially viable fusion reactors. The harnessing of fusion reactors would be instantly revolutionary as opposed to the incremental progress solar promises. Therein lies the difference. Once is not necessarily better than the other.

And it's not a zero-sum game.

[audunw]

I would say it’s clear that solar panels are absolutely working extremely well today, at least as long as you don’t live too close to the poles.

Renewables all together is growing faster than nuclear ever did. And solar is now a huge part of that.

We have models where solar or solar+wind is providing all the power to everything from small remote weather stations through houses to large islands. Some small countries and regions are getting close too.

It’s clear that we have all the technologies we need to do 100% renewables. There’s studies that indicate that the long term costs of this is lower than the traditional fossil and nuclear energy infrastructure. We just need to build the factories to continue scaling up. And of course the transition is more expensive than it’ll be when we just maintain and expand on the system.

[ffgjgf1]

> all the power to everything from small remote weather stations through houses to large islands

Not without very large capacity gas/etc. plants available on standby (unless you’re fine with will below 99% availability)

[jfengel]

I'm fine with gas plants available on standby. If they run 1% of the time, then they are no longer a significant contributor to climate change.

Even if they have to run 10% of the time, we've still taken an enormous cut out of greenhouse gases. We would turn our attention to many other sources of greenhouse gas (agriculture, concrete, transportation, etc.)

[Qwertious]

Or batteries.

Batteries have huge potential, simply due to the fact that they're so broadly defined - must store energy, output it as electricity on demand, and be cheap. There's a high chance that we find some way to make grid-scale batteries extremely cheaply, in the future.

In the mean time, getting to 90% will basically stop climate change in its tracks, giving us time to research dirt-cheap batteries.

[bialpio]

It doesn't even have to always be electricity on demand, sometimes we also need heat. I wonder if heat storage will be a thing we'll have in the households (or maybe it's enough to have it in district heating facilities?).

[pfdietz]

The gas can be hydrogen, produced with renewable electricity by electrolysis.

[WillAdams]

Don't molten salt and similar energy storage technologies augur well for that?

[marcosdumay]

The nice thing about power plants on stand-by is that they emit almost no pollution.

(And yeah, batteries will probably never be enough for any place out of the tropics.)

[immibis]

We have to get fine with below 99% availability.

[iceyest]

Less then 99% means not having a working fridge for 3-12 hours or more in 30c heat so there went all your perishable foods. It means no lights in the house will work. No cooling or heating of any kind. No computers. No phone. None of your other random applicances will work either. None of the stuff you use to navigate a city like street lights will be working. Of course it can be mitigate with a generator or an expensive battery bank with solar panels provided you don't have a large enough load. Of course solar panels only work during the day so if the outage lasted into the night then you better hope to have a large enough bank to power all your essential equipment.

Suffice to say, less then 99% available is pretty terrible. You should come down and talk to a South African.

[nicoburns]

> or an expensive battery bank

Expensive for now. I'd expect that to be a cheap battery bank in <10 years.

[SoftTalker]

It depends how that's distributed.

If we had one hour per day without power that would be about 95% availability. Most of us wouldn't even notice that if it happened in the middle of the night.

If we had 100% availability with an 18-day stretch without power that would be about 95% availability, but it would be hugely disruptive.

[ffgjgf1]

Why? I don’t agree that wouldn’t be at all acceptable.

And even > 90% would be very expensive to achieve in winter in much of Europe (of course there are alternatives to solar so it’s not such a huge issue)

[FrojoS]

Go to a country with just that and witness how stupidly wasteful it is to have an energy grid with regular outages. Everyone who can afford it has an expensive backup generator, batteries, etc. For industry, it's a disaster.

I live off-grid, with solar and LifePo4, but I'm not naive enough to think that would scale to an economy any time soon. And for the record, no below 99% availability should be seen as unacceptable.

[throwAGIway]

Why would we do that? I'd rather pay more than this.

[orson2077]

Don't take this the wrong way, but I envy your naivete. You are extremely optimistic about people and politics.

[XMPPwocky]

How so? To my ears, "we need to accept significant degradations in the availability of electricity" is a deeply pessimistic statement.

[more_corn]

That’s funny. My take is exactly the reverse.

Solar power can 100% solve our energy needs today. It’s cost effective at the unit level. It works at scale. It decentralizes nicely. Did I mention that it works? Every home could have rooftop solar for less than it costs to produce centralized power plants. (I have rooftop solar and it cost significantly less than a new car now my power costs won’t go up for 20 years at which point the panels might need a refresh but that part of the system is the cheapest part)

We could easily flip from subsidizing fossil fuels to subsidizing rooftop solar today and realize significant gains (higher roi by shifting the investment). If you spent one years investment in fusion and fossil fuel subsidies on deploying rooftop solar and grid scale batteries you’d change the energy story permanently. Energy would suddenly be plentiful. Fossil fuels would permanently shift out of relevance. Fission reactors would look like quaint and staggeringly expensive tools of a bygone age. And fusion which DOES NOT WORK. Would look even more like a silly dream.(We are no closer to fusion than we were 30 years ago.)

Why the fuck are we still talking about fusion when we have something that works?

[bruce511]

I agree with everything you say about rooftop solar. If you have a suitably unshaved roof, and you are in a reasonably sunny climate, the current economic math works. And as energy costs go up, and capital costs come down it works better all the time.

That said, we still need a grid to distribute electricity to places that consume more energy than roof space. Think apartment blocks, factories etc. And yes, a huge chunk of that load can still be supplied by grid-scale solar and wind etc.

Even with large-scale storage (another fruitful place to spent investment money) there's going to need to be peak-generation.

However you look at it, I don't think fusion will be the answer. Since fusion was first proposed and the landscape of requirements have shifted. By the time it's practical, it'll be solving a problem we dont have.

The science may lead to a working reactor. But no one will build it at scale because it simply won't solve the problem well have then.

[jandrese]

Grid scale storage has lagged behind solar and wind generation, but it's starting to catch up. By the time we have a viable commercial fusion power plant all of the grid storage issues will have been long since solved.

[romski]

Find the graph of GW of solar installed over time

[arrowsmith]

> Solar panels today work

But not tonight

[choilive]

Luckily about 50% of the Earth is lit up by the sun at any moment and energy storage capabilities are advancing much faster than fusion's capabilities are.

Distribution and storage are way more tractable problems than fusion.

If you want to be really ambitious you can go to space and have 100% capacity :).

[okanat]

Unless you colonize it, you cannot utilize 50% of the Earth's energy. If it proven anything, what the war in Ukraine showed us is how terrible of an idea to outsource energy, especially to nations who don't share interests with us.

[janalsncm]

It would be interesting if there was a global grid and market for (hopefully clean) energy so that a joule of energy could be sold anywhere instantaneously, just like any other commodity. This would allow countries to quickly power up without even building a power plant. It would also allow large base load power stations (like nuclear) to have permanent demand.

Of course there are technical challenges of building out UHVDC everywhere. This probably means a joule isn’t perfectly fungible.

Perhaps Europe’s problem was being overly reliant on only one supplier.

[IMTDb]

A global and free market for electricity means that African citizens are going to have to outbid bitcoin miners and ai trainers for electricity.

I would much rather see a world where governments are at least partially in charge of the grid to ensure that their population gets their share of the capacity.

[npoc]

It will be almost impossible to not outbid bitcoin miners for electricity due to the fact that mining is a non-geographically constrained free market where miners are not profitable unless their electricity cost is very close to zero (i.e. otherwise wasted energy). As soon as there's other demand for the same energy, bitcoin mining will instantly become unprofitable in that area and they will need to relocate.

[BobaFloutist]

Well they didn't say a free market. I would certainly hope for some treaties making sure everyone gets a baseline before extras get put up to bid.

[metadat]

This is a nice fantasy, but you still need the infrastructure to efficiently transmit said energy.

[Larrikin]

Needing the sun for energy and improving solar panel feels like trying to make the best ICE engine ten years ago or working on an expert system for AI in the 90s. There are obvious immediate gains in the short term, but research has shown there is something else better out there and its best if someone is doing the R&D now so we can get a leap frog moment eventually.

[bruce511]

Improving solar panels might be nice, but the panels themselves are a cheap part of the system. And the big gains have already been made.

Solar panels are now being produced and install at gigawatt scale. Per year. (Over 400gw per year, and climbing). Capital is being supplied by individuals (rooftop) and companies (utilities).

I'm not sure what leap-frog tech you have in mind, but its not fusion.

In the 60s fusion was touted as "free energy for all". But fusion is very (very) much not "free". The cost of a fusion plant will make your eyes water. The lead-time to build it will be measured in years. The output from one plant won't move the needle (we'd need hundreds of them). Electricity from these plants will be expensive, because at the very least it'll need to generate a return to the investors. And that's before we factor in running costs which (I guess) won't be cheap.

The problem with fusion is not physics, it's economics. As long as we present fusion as a physics problem interest remains. Because once we view it as an economics problem it dies overnight.

[jmpman]

Will orbiting solar panels ever work? Now that starship is viable, payload cost to orbit will dramatically drop. Is it cheaper to have orbiting solar plants than solar/battery(or whatever long term energy storage)? It’s that baseload problem which makes the manmade fusion/fission attractive.

[mr_toad]

For a space based solution you have all the costs of solar, plus launch costs, plus the receivers are very large and costly themselves.

It’s never going to be cheaper than solar, but it does have the advantage of working at night and through cloud cover.

In the very long run it might make more sense to launch whatever’s using the power into space as well, saving on the cost of the transmission and receiving infrastructure, but also removing further sources of pollution from Earth.

[ComputerGuru]

No heat dissipation is a huge con.

[SoftTalker]

So you have orbiting panels that will do what? Beam the energy back to earth? Isn't the sun beaming energy to earth directly? What problems do orbiting panels solve?

[choilive]

I actually don't think space based solar to beam it back to Earth will ever really be practical short of a space-elevator style tether to transmit the electricity down. But some of the pros would be as follows.

* Capable of 100% capacity - power generation can be 24/7/365 if in orbits around the sun or stationed at the Earth-Sun Lagrange points.

* Greater panel efficiency - less energy lost to the atmosphere that can be captured by the panels, closer orbits will increase efficiency even more due to more power/area

* Surface area - minimum 1x10^20 square kilometers of area you can build panels

There are of course many cons - but it could be a vital part to a space based industry - you need a lot of fuel or power to really do anything in space, and the power from space based solar could to be used to kickstart a fuel production facility off Earth. Fun stuff but not very terrestrially relevant.

EDIT: Some more numbers: You get about 40% more power/area in space vs on the ground. You need about ~22 TW to "power" humanity. So you need about 70,000 km^2 of space based solar assuming 25% end to end efficiency, which might be a generous estimate. So lets round it to 100,000 km^2. But thats a significantly smaller area than the terrestrial equivalent of about 500,000 km^2. Right now it costs about $1B installed for a square kilometer solar installation, so we if can build solar panels on the Moon or something anywhere close to the same cost as on Earth (very very BIG if), potentially a difference of $400T dollars at todays terrestrial prices.

[Someone]

> You get about 40% more power/area in space vs on the ground. You need about ~22 TW to "power" humanity. So you need about 70,000 km^2 of space […]. So lets round it to 100,000 km^2. But thats a significantly smaller area than the terrestrial equivalent of about 500,000 km^2.

Those number are inconsistent with each other. Seems you calculated with 400% more power/area in space vs on the ground. That seems incorrect to me, as it would make space solar convert close to 100% of incident solar energy to electricity.

[choilive]

Ground based solar has a capacity factor of about ~25% depending on location, while a space based installation would have nearly a 100% capacity factor. So to generate the same amount of energy per year you need about 4x as many panels on the ground. I probably should not have said power but instead something like exajoules/year.

[pfdietz]

Another important issue is that in space, PV can be extremely thin. The actual active layer of semiconductor can be maybe 50 microns (for silicon) or less than 1 micron (for CdTe). This also suggests solar-powered electric propulsion in space can have high acceleration, limited by heat dissipation in the engine.

[rowanG077]

Solar panels clearly don't work wel enough to be able to solve our energy demands. A very significant portion of the day they don't work at all.

[pfdietz]

The conclusion of the experts who have studied renewables is that they very clearly can be made to work, and more cheaply than nuclear.

https://ieeexplore.ieee.org/document/9837910

"With every iteration in the research and with every technological breakthrough in these areas, 100% RE systems become increasingly viable. Even former critics must admit that adding e-fuels through PtX makes 100% RE possible at costs similar to fossil fuels. These critics are still questioning whether 100% RE is the cheapest solution but no longer claim it would be unfeasible or prohibitively expensive."

[burnished]

We call that the 'night' and our battery tech is improving enormously. Personally I hope solar becomes so cheap that mechanical batteries become popular - pumped resevoirs, inexplicable wood flywheel

[ffgjgf1]

> We call that the 'night

Or winter sufficiently close to the north pole (i.e. significant proportion of Europe). Days get short and it’s usually cloudy so solar becomes extremely inefficient.

[immibis]

Luckily, most people don't live there and they are well connected to a big grid that isn't like that.

[ffgjgf1]

Well… over 80 million of people live in Germany: https://www.iea.org/data-and-statistics/charts/monthly-gener...

Over-provisioning by 7x might not be extremely practical.

I guess there is a lot of space in Spain that could be filled with solar panels (production only falls by ~50% there in winter so it’s not to bad) but there is certainly not enough grid capacity to transfer all of that north (and building new infrastructure is painfully slow and expensive in Europe so it will take a few decades to solve that)

My point is that solar is only a part of the solution and wind/etc. is probably more practical and more important in much of Europe.

[BirAdam]

Personally, that lack of space is a thing that bothers me. Screw the plants and animals, we need solar farms, right?

[sdenton4]

Exactly this! Fusion power is eight minutes away. Always has been.

[ethn]

Schockley-Quiesser limit

[Qwertious]

Only applies to single-junction cells. 68%-efficient solar panels are quite theoretically possible, they'll just be incredibly difficult to manufacture cheaply. The current world record for solar panel efficiency is 47.6%.

[ethn]

I agree, however the author is convinced about current popular solar panel technology.

Indeed even theoretically we can do 86% multi and 99% with quantum dots——in the current state of technology these remain science fiction considering the commercial manufacturing processes available.

[lambdaone]

That's certainly a hard limit for a cell with a single P-N junction. However, with a bit of ingenuity, we can do much better than that; see https://en.wikipedia.org/wiki/Shockley%E2%80%93Queisser_limi...

[ethn]

Sure there are many novel solar technologies that subvert the SQ assumptions thereby avoiding the conclusion. However, the author of the parent post believes that existing technology today is sufficient.