Things are Starting to Warm Up. 21

[dik]

https://www.reuters.com/world/asia-...mothers-bear-brunt-climate-change-2022-06-14/

a sign of things to come... hold on to your hats, folks.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Do you feel any better?

-Dik

 

[Tomfh]

hummm, I wonder if another "gravity energy storage system" ?
ie a scam

The gravity tower is really stupid. It’s a Rube Goldberg energy storage device.

This sand battery makes perfect sense, if it indeed works.

 

[LionelHutz]

3-5MWh of grid connectable battery can fit into a transportable e-house, so 8MWh of sand isn't competitive at all to the energy density of batteries or the energy storage of a big battery bank. It might be competitive on cost per MWh.

The 100kW energy transfer rate is due to the rate the heat can be put into or removed from the big pile of sand. That is also a low transfer rate compared to batteries. The above mentioned e-house could transfer energy at about a 1-4MW rate, depending on battery vs grid connected inverter capacity installed inside. I've seen one recently, it was 3MWh and had 4MW of inverter and was for stabilizing wind power.

I also highly doubt they are conveying the sand around during this storage process. That would make no sense.

 

[TugboatEng]

From Pud's link.

 

[rb1957]

why not have static sand and pump the water through it ? Maybe have a mixer to circulate the sand in the tank to get an even heating ?

But this does sound to me to be as feasible as that gravity storage concept.

another day in paradise, or is paradise one day closer ?

 

[TugboatEng]

Sand is a very good insulator. If you add water to it or start mixing it around you lose the property that helps it store energy.

 

[rb1957]

I'm picturing a heat exchanger, with a bunch of tubes running through the sand.

But if sand is a good insulator, how will the heat get distributed through the sand ?
Maybe this is why they have moving sand ?

So we'd have a bunch of electrical elements heating the sand, and a bunch of tubes removing the heat.
Why not have one do both ? Surplus electrical energy heats a fluid which heats the sand. When we want to generate power we run the fluid through a reverse system (cooling the fluid) ?

This is such a croc !

another day in paradise, or is paradise one day closer ?

 

[TugboatEng]

Heating the sand is simple, a tunnel or conveyor oven would do that well.

Getting the heat out would probably be a bit more challenging. The key is to minimize the distance heat has to move through the highly insulating sand. This could be done by pouring the sand over a flat plate. A slight slope and some vibration will keep the sand moving in a thin layer over the surface.

Another option would be to simply waterfall the sand and then blow air through it. This would require treatment of the air to remove dust.

In Pud's example a separate container with fluidized bed is used. I don't think this would be viable except on the largest scale.

 

[Tomfh]

If it needs conveyors etc then yeah, we’re back in gravity tower territory.

 

[TugboatEng]

The very thing that works against gravity tower works in favor of this. The amount of energy required to conveyor 100 tonnes of sand up to 20 feet of elevation is only 2 KWh. That contribution to inefficiency would only be 0.2% (multiply by 3 if the power for the conveyor comes from conventional sources) if the unit truly stores 8 MWh of useable energy.

 

[dik]

There's another big wrinkle in climate change, with the cards stacked against fixing it:

https://theconversation.com/energy-...in-52-countries-so-how-can-we-leave-it-185753

So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[dik]

Time to move on...

thread1618-496614

So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[TugboatEng]

We finally settled on a climate change engineering subject and now it swings right back to politics.

P.S. I enjoy the politics...