Katoomba Monthly Temp average set to be SMASHED!!! AGAIN!!!

[woodPixel]

[woodPixel]

This is the cloud generating idea I was going on about many pages back.

Turns out that its a thing!

If we can hook these up to wind turbines to generate the power, we can put them on pontoons.

Researchers successfully trial world-first cloud-brightening technology off Townsville - ABC News (Australian Broadcasting Corporation)

[AlexS]

It sounds promising, but as the researcher said, it's not a permanent solution.

[woodPixel]

Artificial intelligence helps researchers produce record-setting catalyst for carbon dioxide-to-ethylene conversion

Imagine this on the farm!

A few windmills, spinners on the roof, solar panels, heat panels.... all this backed into plastic batteries and these new CO2-->Ethylene generators.

Magic!

[woodPixel]

Well, that won't get me On The List

In a First, Renewable Energy Is Poised to Eclipse Coal in U.S. - The New York Times

Seems that renewables now out-generate coal in the USA.

Death to COAL!

[Lappa]

Looks promising but there are a lot of ifs and buts in the article. It will certainly be interesting to see what happens when industry gets cranked up again.

[woodPixel]

• 250MWh of energy
• £85m
• Store power for many weeks

Climate emission killer: construction begins on world’s biggest liquid air battery | Renewable energy | The Guardian

We need Thousands of these! Put them everywhere.

Local storage. Industrial estates. Data centres (they can also use the heat and cold)

[FenceFurniture]

Sounds very interesting indeed. I wonder how big the footprint is (including the required turbine, and I wonder what it's efficiency is?

[GraemeCook]

Sounds very interesting indeed. I wonder how big the footprint is (including the required turbine, and I wonder what it's efficiency is?

Me, too.

Considering that air liquifies at -196*C it will require one hell of a refrigeration system to both liquify the air and to hold it below -196 degrees.

If the 'fridge fails, does it go bang?

[FenceFurniture]

... and to hold it below -196 degrees.

If the 'fridge fails, does it go bang?

It doesn't need refrigeration after it is compressed (AFAIK) - the containment keeps it liquid. (think of a regular welding gas cylinder)

[GraemeCook]

It doesn't need refrigeration after it is compressed (AFAIK) - the containment keeps it liquid. (think of a regular welding gas cylinder)

I visited an Otsuka air liquifaction plant in Shikoku, Japan many years ago and refrigeration was certainly used in the surprisingly complicated manufacturing process and in the bulk storage area. Deliveries were essentially made in "thermos flasks".

Just checked the science, remembering air is c.20% oxygen. "....oxygen cannot be liquified above a temperature of -119 degrees Celsius, no matter how much you compress it...." QES.

[FenceFurniture]

Well, something doesn't add up. Oxygen boiling temp is -183°C. Argon (commonly used in Welding) boiling temp is -186°.
Plumbers etc do not carrying Argon around in anything but a pressurised tank.
Oxy-Acetylene is a bottle of Acetylene and a bottle of oxygen isn't it?

It might be a case of not being able to be liquefied above -119°C regardless of pressure, but once it is liquid then it might be able to be held that way with pressure.

Where's a Physicist when you need one?


My overall point being that if it requires that level of refrigeration to keep it liquefied then it can't possibly be viable as a form of power storage - it would use itself up in no time at all.

[GraemeCook]

Well, something doesn't add up. Oxygen boiling temp is -183°C. Argon (commonly used in Welding) boiling temp is -186°.
Plumbers etc do not carrying Argon around in anything but a pressurised tank.
Oxy-Acetylene is a bottle of Acetylene and a bottle of oxygen isn't it?

It might be a case of not being able to be liquefied above -119°C regardless of pressure, but once it is liquid then it might be able to be held that way with pressure.

Where's a Physicist when you need one?


My overall point being that if it requires that level of refrigeration to keep it liquefied then it can't possibly be viable as a form of power storage - it would use itself up in no time at all.

My understanding, FF, is as follows:

• Acelylene gas is actually disolved in acetone in those gas cylinders,
• Oxygen bottles contain pressurised oxygen, not liquified, and the OP was all about liquifaction.

SCUBA dive bottles are normally filled with straight air compressed to about 3,000 psi pressure. Back in the sixties I saw the aftermath of where the valve was broken off a dive bottle converting it into a self propelled rocket (literally). It went through a wooden roof rafter and corregated iron roof - very clean round hole - and landed about a kilometre away. Scary!

Fully agree with your overall point.

[FenceFurniture]

Oxygen bottles contain pressurised oxygen, not liquified, and the OP was all about liquifaction.

Ah yes, probably right.

BUT your bottle of LPG gas for the BBQ is definitely liquid (we can feel it swirling around) and doesn't require refrigeration. Propane liquefies at -42° (significantly higher than O2), but the point is that the laws of physics apply equally - but scaled.

Consider this: if it did require refrigeration to stay liquid - and there was a problem with the fridge - that hole in the wooden roof would be a stroll in the park compared to what one of those big boys would do.


Back in 1990 by sheer chance I happened to witness a BLEVE (Boiling Liquid Expanding Vapour Explosion) near Sydney Airport. I happened to be standing on the front porch having a fag at home in Miranda and saw the MASSIVE explosion fully 14 kilometres away (we had a good clear view right to the city from there). We all thought a plane had gone down! Somehow, I had the presence of mind to start counting the seconds when I saw the second one go up. The sound took about 40 seconds to reach us, which confirmed it was somewhere near the Airport. It threw a 60,000 litre tank 150 metres away. (that's about a 4 metre cube - 60 cubic metres - twice the volume of my entire shed which is 5x3x2 roughly). What would the tank weigh - 5 tonnes or something? Sans gas of course!

[RossM]

Air was first liquefied by Carl von Linde, who used a very clever trick to use the use air cooled by expansion to pre-cool itself - a feedback effect that produced the low temperatures needed to liquefy the so called "permanent" gasses that air is comprised of.

The air is compressed, increasing its temperature. The hot high-pressure air is then cooled in a heat exchanger and then further cooled by a second heat exchanger to below ambient temperature. The cool, high-pressure air is then allowed to expand rapidly through an expansion nozzle into a collection vessel, which causes it to become very cold. So far, it's just a refrigerator, but Von Linde's trick was to use the cold air that didn't liquefy from the collection vessel and pipe it to the high-pressure air coming from the first heat exchanger, thus cooling it. The more the high-pressure air is cooled before expansion, the colder the air will be after expansion, further cooling the high-pressure air, making the air even colder... positive feedback!! The longer it runs, the colder it gets.

Here is an interesting paper on using liquid air as energy storage:
http://jestec.taylors.edu.my/Vol%201...%20496-515.pdf