Solar energy modules may help solve renewable storage issues

September 2, 2023 10:15 PM

These solar energy modules generate enough heat to melt metal. It's hoped they can help solve renewable storage issues. Renewable energy company RayGen has officially opened its $27 million solar and thermal power plant project, in north-west Victoria.
posted by chariot pulled by cassowaries (24 comments total)

Nice! What is most striking is how the cost of facilities like this keep coming down, making facilities like this viable. It's a solid reason for optimism.
posted by From Bklyn at 11:31 PM on September 2, 2023 [4 favorites]

441 modules, each producing 1MW electricity, and 2 MW heat.
posted by constraint at 12:07 AM on September 3, 2023 [1 favorite]

Since they are simple mirrors rather than photovoltaic panels I expect they should be easier to maintain, too.
posted by rikschell at 3:55 AM on September 3, 2023 [2 favorites]

And, since I am apparently 12, I giggled at the "supply energy to 1700 Victorian homes" with the implication that they've invented time travel.

Yes, I know.
posted by Mogur at 5:18 AM on September 3, 2023 [16 favorites]

Well they can be quite drafty.
posted by condour75 at 5:51 AM on September 3, 2023 [4 favorites]

Earlier versions of the mirror approach had a problem of killing birds (they would catch on fire when they flew through the concentrated light); I wonder if they have solved that or it is just considered an acceptable side effect of the facility.
posted by Dip Flash at 6:20 AM on September 3, 2023 [2 favorites]

The 441 modules sit atop large towers and each tower is capable of producing one megawatt of electricity

The photo in the article only shows 4 modules (each with 1,000 mirrors).

Is 441 modules the projected total number when completed, or is RayGen too modest to show the full scope of the system?
posted by fairmettle at 6:27 AM on September 3, 2023

Soon enough they'll be using it to burn enemy ships in the harbour.
posted by blue_beetle at 7:08 AM on September 3, 2023 [4 favorites]

The photo in the article only shows 4 modules (each with 1,000 mirrors).

I’m reading it as multiple modules per tower?

The 441 modules sit atop large towers and each tower is capable of producing one megawatt of electricity and two megawatts of heat.

Unclear on what a module consists of.
posted by Artw at 7:27 AM on September 3, 2023 [3 favorites]

I'm guessing the modules are these little two inch square jobbies. 441 of those would make a square receiver 42 inches wide, which looks about right.

Getting 2.5kW out of a tiny little thing like that is impressive. A water cooling loop grunty enough to keep on pulling 2.2MW of heat off the back of 441 of them, even more so. You'd want the mirrors set up to defocus super fucking quickly if the pump stops, or maintenance is going to get very expensive.
posted by flabdablet at 7:31 AM on September 3, 2023 [3 favorites]

With precisely flat mirrors and accurate enough positioning, would it be possible in principle to use a system like this nefariously, frying aircraft and satellites?

Or does atmospheric scattering torpedo my daydreams of world domination again?
posted by Western Infidels at 7:48 AM on September 3, 2023 [1 favorite]

With precisely flat mirrors and accurate enough positioning, would it be possible in principle to use a system like this nefariously, frying aircraft and satellites?

Wasn't there some movie in the early or mid 1980s that had mirrors in space being used to zap targets on the ground?
posted by Dip Flash at 8:33 AM on September 3, 2023

You might be thinking of the government’s Project Excalibur.

Or, if you prefer, the more realistic version.
posted by q*ben at 8:39 AM on September 3, 2023

Mogur, I thought you might also enjoy the town's name of Carwarp.
posted by doctornemo at 8:46 AM on September 3, 2023 [2 favorites]

I agree with From Bklyn. It's good - heck, necessary - to see this kind of experimentation.
posted by doctornemo at 8:47 AM on September 3, 2023 [1 favorite]

The storage is something I'd hadn't seen before, all other proposals like this featuring either a phase change material or higher temps with something like liquid sulfur. I wonder what the round-trip efficiency of the storage is.

As an aside is there any name that narrows location down globally less than Victoria? Had to clickthru to see which one this was. Maybe something like Newport.
posted by Mitheral at 10:31 AM on September 3, 2023 [1 favorite]

I whole heatedly endorse these prototypes, what's more, i endorse banning all new fossil fuel development and shutting down existing fossil fuel use and replacing it with these (and demand management and wind, and hydro, and where suitable pumped storage, tidal power etc) , not just adding these to an already growing fossil fuel use.

The article is light on metrics (lol) but even at twice the price of power, having a power supply that doesn't cause a mass extinction is worth the investment.

Many of the workers in fossil industries have important relevant skills to these new installations and those that don't should be retrained or allowed to comfortably retire. And the fossil execs should be tried for conspiracy to commit mass murder and if convicted, spend the rest of their lives breaking rocks with tiny hammers while their families pay back their ill-gotten gains.

While not every location is suitable for large arrays like this, even cloudy cold climates can get reasonable power generation as a supplement to other methods. Solar thermal handles diffuse light better than solar PV.
posted by AnchoriteOfPalgrave at 11:45 AM on September 3, 2023 [1 favorite]

I wonder what the round-trip efficiency of the storage is.

70% claimed. I'm sure they're losing a bucketload on that low-temperature-difference ammonia turbine, but they're charging the cold pond with a heat pump that seems to have a very impressive CoP of 6.3 and charging the hot pond with what would otherwise be waste heat, so that's why it's not completely dismal.

It's nifty that they're using the same generator as geothermal plants.
posted by flabdablet at 2:09 PM on September 3, 2023 [3 favorites]

What is most striking is how the cost of facilities like this keep coming down, making facilities like this viable. It's a solid reason for optimism.

Yes, indeed. Since I started following the renewable energy space as part of my job, I've become a lot less doomy about the climate.

Don't get me wrong, it's still a hugely alarming crisis! We are in deep trouble, and have enormous work ahead of us to get out of it. But news like this -- and hundreds of other stories about green energy trends and breakthroughs large and small -- make it clear that the people shrieking "WHY ISN'T ANYBODY DOING ANYTHING!!1!!" aren't paying close enough attention. People are doing a heck of a lot.

Is it "enough"? We won't know for decades. Societies and economies are like big ships that are very slow to turn. But the turns are happening, and beginning to become visible.
posted by Artifice_Eternity at 2:58 PM on September 3, 2023 [5 favorites]

It has moving parts, so it can't compete with fixed solar PV on cost or reliability.

Also, my engineering efficiency sense got all messed up by the … hot and cold water pit, allowing it store excess heat energy in water and use the temperature difference to generate electricity caption. You're going to get dismal energy recovery from the temperature differences out of water that isn't high pressure steam and river water. Monsieur Carnot says “Non!”
posted by scruss at 4:26 PM on September 3, 2023

It beats the hell out of Solar PV on storage capabilities though.

70% is a lot better than I would have hoped let alone guessed. That's up there at the low end of pumped hydro.
posted by Mitheral at 6:30 PM on September 3, 2023 [2 favorites]

It's great to see technology like this being put into practice where it can be properly tested at scale and in real situations! Solar PV/batteries seem to have advantages in maintenance and storage capability, but a system like this may win out in places where solar PV doesn't work as effectively due to lower sunlight levels. I hope and assume (as flabdablet points out) they have something in place to stop the towers burning to the ground if the cooing system has a glitch. Given the people working on this are at least 1,000 times smarter than me, I'm pretty sure they've got something in mind.
posted by dg at 6:51 PM on September 3, 2023 [3 favorites]

Good that they are experimenting although the relentlessy falling cost curves of PV solar are going to be hard to beat.
posted by storybored at 8:48 PM on September 3, 2023 [2 favorites]

It has moving parts, so it can't compete with fixed solar PV on cost or reliability.

Might compete with flow batteries on both, though.

Monsieur Carnot says “Non!”

It's not quite as bad as it looks at first glance, because one of the thermal stores is being charged with a heat pump for which the claimed CoP is 6.3.

The flip side of the low Carnot efficiency inherent in recovering high quality energy from a smallish temperature difference is the high Carnot efficiency available for creating smallish temperature differences from high quality energy - especially when the temperature difference actually being created is between ~0°C and ambient rather than 0°C and the hot store.

As long as they're careful about not fucking up thermal stratification in the storage ponds, 70% round-trip efficiency for electric energy storage doesn't strike me as implausible.
posted by flabdablet at 8:51 PM on September 3, 2023