Science Cryogenic storage offers hope for renewable energy.

[Notebook]

The world's largest cold energy storage plant is being commissioned at a site near Manchester.
The cryogenic energy facility stores power from renewables or off-peak generation by chilling air into liquid form.
When the liquid air warms up it expands and can drive a turbine to make electricity.
The 5MW plant near Manchester can power up to 5,000 homes for around three hours.

http://www.bbc.co.uk/news/science-environment-37902773



And, we get free energy!

Dr Sheridan Few, Research Associate at the Grantham Institute, Imperial College London, described a phenomenon unique to this technology.
"There's the storage of the energy, and the generating of the energy. You can make use of waste cold and waste heat... because you're putting both electrical and thermal energy in, the amount of electrical energy you get out, can in some cases end up being more than the electrical energy you put in."

 

[Enjo]

Well, it might finally start to make sense to build renewable energy sources, because you'll not waste the energy on peak, and you'll meed demand on trough.
However I'm not a PhD, but this phrase raises my doubts:
"the amount of electrical energy you get out, can in some cases end up being more than the electrical energy you put in."

But it's OK. It's still (almost) free energy.

 

[Notebook]

Indeed. That's a bit of a gift to a journalist, but we know what he meant.

N.

 

[Artlav]

That's a bit odd.
I thought refrigeration was highly inefficient, so cryogenic storage would be rather pointless.

Is it a matter of cost? That is, offsetting inefficiency by having cheaper scaling?

 

[Notebook]

Maybe the storage is very short-term, a few hours, then the plant idles till near a demand time?

N.

 

[Urwumpe]

Well, I can actually imagine a scenario, in which the idea of getting "more energy out that was put in" can actually work. When the energy was stored at cold air temperatures and is taken out at high temperatures... but I doubt that such a difference in air temperature can really happen.

 

[Enjo]

Or maybe he just meant that the system uses heat from the landfill, that would otherwise be wasted.
But the energy still doesn't come from nowhere. It was put in the trash first. But alright...

 

[jedidia]

I'm confused. The term "waste cold" doesn't fit with my understanding of thermodynamics, which is admittedly limited.

 

[Notebook]

Place I worked at had a Heating and Ventilation Manger who worked in "Tons of Coolth". Seemed to work, we never overheated. Except when the power failed.

N.

 

[boogabooga]

So, we've given up on battery technology and decided to just go brute force?

I would say pump water up to a great height. That energy is easy to store. The container only needs to be watertight with no thermal insulation concerns.

 

[Zatnikitelman]

I just can't see how this is thermodynamically more efficient than anything else we already have. Just because some peak load power comes from a bottle of liquid gas, doesn't mean the energy (and then some) wasn't used in compressing it, it was just used at a different time.

So, we've given up on battery technology and decided to just go brute force?

I would say pump water up to a great height. That energy is easy to store. The container only needs to be watertight with no thermal insulation concerns.

https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity

 

[Enjo]

I just can't see how this is thermodynamically more efficient than anything else we already have. Just because some peak load power comes from a bottle of liquid gas, doesn't mean the energy (and then some) wasn't used in compressing it, it was just used at a different time.

And that's the whole point - to provide a buffer for renewable electricity, that comes in peaks, that nobody uses, therefore it gets wasted. With a buffer like this you will transfer the peak to the trough of relative input/output of power.

 

[RisingFury]

"the amount of electrical energy you get out, can in some cases end up being more than the electrical energy you put in."

But it's OK. It's still (almost) free energy.

Industrial processes can result in waste heat. In chemical reactions, for example, you can put in some electrical energy to transport and mix them, but get a lot of heat when reacting them.

They're not implying a perpetual motion machine or some magical free energy device. Just though I'd clarify.

Is it a matter of cost? That is, offsetting inefficiency by having cheaper scaling?

Exactly. It doesn't need to be the most efficient as long as it's cheap.

So, we've given up on battery technology and decided to just go brute force?

No, we haven't given up on batteries. Electric vehicles might end up solving the supply / demand problems, given that they'll all have a 100 kWh battery.

This is obviously a research facility. 5 MW for 5000 homes is 1 kW per home, for 3 hours. It's obviously not enough to do it on a large scale. They're exploring the concept to find out how expensive it is and how it can be improved and if there are any hidden variables not yet considered.

I would say pump water up to a great height. That energy is easy to store. The container only needs to be watertight with no thermal insulation concerns.

Pump water storage is an old idea, but might not be the best one. Energy-pump-release-energy cycle is about 30% efficient, but the big issue is energy density. 1 m^3 of water weighs 1000 kg. Pump that up 10 m and you get 100 000 J. With inefficiency, you get 30 000 J back.

A lead car battery rated at 50 Ah has 12 V * 50A * 3600 s = 2 160 000 J of energy. So at 10 m fall, you need about 72 m^3 of water to equal one typical battery. Yes, increasing height gives you more energy, but height isn't always available. UK doesn't exactly have mountains...........

 

[Notebook]

Mountains in the UK, oh Yes!!!!

https://en.wikipedia.org/wiki/List_of_mountains_and_hills_of_the_British_Isles_by_height

Mostly Scotland, as you'd expect.
Did give a boost to hydro-power North of the border:
From 2013
http://www.bbc.co.uk/news/uk-scotland-22447168

Should mention the Dinorwig Power Station in Wales. I think its the largest of its type in the UK.
https://en.wikipedia.org/wiki/Dinorwig_Power_Station#Operation

N.

 

[RisingFury]

1344 m "mountain"? We call that an afternoon hike :lol:

Point stands, though. A storage facility that relies on molten salts, compressed air, batteries,... can be built anywhere, while hydro storage is conditional.

 

[Notebook]

mountain
image: http://cf.ydcdn.net/1.0.1.64/images/dictionaries/websters5.jpg

a natural elevation of the earth's surface, typically larger and steeper than a hill
a chain or group of such elevations
a large pile, heap, or mound
a very large amount

Origin of mountain
Middle English montaine ; from Old French montaigne ; from Vulgar Latin an unverified form montanea, for Classical Latin montana ; from montanus, mountainous ; from mons: see mount

of a mountain or mountains
situated, living, or used in the mountains

Read more at http://www.yourdictionary.com/mountain#hx67q0lEHaWwyAMw.99

I blame the French.

N.

 

[Urwumpe]

1344 m "mountain"? We call that an afternoon hike :lol:

Well.... as if height has anything to do with how hard it is to climb....

The Brocken mountain is maybe just 1100 meters high, but has 850m prominence to offer. And Rockall is just 20 meters high, but good luck getting there....

 

[Notebook]

Good animation on their home page:

http://www.highview-power.com/

N.

 

[MaverickSawyer]

1344 m "mountain"? We call that an afternoon hike :lol:

Point stands, though. A storage facility that relies on molten salts, compressed air, batteries,... can be built anywhere, while hydro storage is conditional.

California has a heavy hydro presence, largely due to the fact that the Sierra Nevadas form the backbone of the state and typically run 2-3 km high. Lots of valleys to dam up, too.

 

[RisingFury]

California has a heavy hydro presence, largely due to the fact that the Sierra Nevadas form the backbone of the state and typically run 2-3 km high. Lots of valleys to dam up, too.

California has a lot of dams, sure. Now it just needs some water :lol: