330MW of compressed air energy storage for NI

Capt'n Midnight

http://www.derryjournal.com/news/national/gaelectric-compressed-air-project-to-get-6-5m-euro-grant-1-6851470

The UK's first compressed air energy storage project is to be awarded almost 6.5 million euro (£4.6m) by the European Union.

It will hold air in specially engineered salt caverns under high pressure on Northern Ireland's east coast before releasing it to drive turbines and create power for the grid. The money will pay for environmental impact assessments, planning and design, the Gaelectric firm behind the innovative scheme said.
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The system could generate up to 330 megawatts of electricity - enough to sustain thousands of homes - for up to six hours and the EU said it will contribute to energy security in the UK and Ireland.
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CAES facilities store excess energy from the grid by converting it into compressed air, which is then stored in caverns created within salt layers.

Jim Martin

I wonder what the air pressure will be & how the "special engineering" will prevent the cavern walls from fracturing!

Carawaystick

I saw something about this a few years ago.

The plan then was to use salt caverns off the Antrim coast for natural gas storage.
You drill down into the vast salt domes under the bedrock there and excavate a cavern of required size.

The salt is strong under compressive strength and airtight, and backed by the bedrock about it.

If you are excavating a salt dome under the sea, all you need to do is pump in seawater, and it dissolves the salt and flows out as saltier seawater until its dispersed in the sea.

Jim Martin

So after excavating cavern, I wonder what thickness of remaining salt they have to have to ensure the integrity of the structure?

AngryHippie

Jim Martin wrote: »

So after excavating cavern, I wonder what thickness of remaining salt they have to have to ensure the integrity of the structure?

Depends on the design pressure.
Easy enough from an engineering point of view, provided that there arent major fractures through the salt mass.

Heroditas

"Thousands of homes"
"Up to 330MW"
"Up to 6 hours"

Urgh, fairly light on detail. I'd be interested to see what the total MWh capacity of the project would be.

330MW is a decent size but not if that can only be sustained for 5mins!
However, it could prove to be a relatively useful "peaker".

Markcheese

The salt caverns are already there aren't they ?
We haven't really got anything similar down south have we ? Or could the spent natural gas fields off ballycotton serve ?

Capt'n Midnight

Batteries have been getting lots of publicity but this project is about the same size as total global installations a few years ago. I'd count the 6GW as part of the Lithium Economy hype until it starts happening.

http://www.pv-magazine.com/news/details/beitrag/grid-connected-storage-market-set-to-explode_100013945/

The grid-connected energy storage market will increase from 340 MW in 2013 to more than 6 GW in 2017, according to IHS. The U.S. is set to lead the sector.
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Commercial activity in the grid-connected storage market is currently limited to a small number of regions and IHS estimates that only 340 MW of systems were installed across 2012 and 2013, with these predominately demonstration projects.

Jim Martin

AngryHippie wrote: »

Depends on the design pressure.
Easy enough from an engineering point of view, provided that there arent major fractures through the salt mass.

So we still don't know what the proposed design pressure is - like so many such 'pie in the sky' proposed, so called 'sustainable energy' projects, lacks essential detail!

AngryHippie

Jim Martin wrote: »

So we still don't know what the proposed design pressure is - like so many such 'pie in the sky' proposed, so called 'sustainable energy' projects, lacks essential detail!

For it to have gotten to the stage of making details public, somebody somewhere has done some numbers on it, or they deserve to look silly.
Probably don't jump the gun on it being pie in the sky.

The information that you are looking for would and should be treated as commercial in confidence as they may need to have some PPP to fund it.

Just because you don't know, doesn't necessarily mean nobody does.

Capt'n Midnight

Jim Martin wrote: »

So we still don't know what the proposed design pressure is - like so many such 'pie in the sky' proposed, so called 'sustainable energy' projects, lacks essential detail!

Generally these compressed air storage schemes are used in conjunction with gas turbines so the pressure would be the optimal pressure of a gas turbine.

this says 70 times atmosphere - see also for background on how they work
http://energystorage.org/compressed-air-energy-storage-caes

The key detail is that it's of a comparable size to the existing plants and the geology would seem to be suitable and no new technology is needed. Someone patented using a mist of water to cool / heat the air to ambient during the cycle so maybe some new tech could be used.


The bigger question is the volume of air stored. Six hours is good. But it would be interesting to see if they could they expand it further if more caverns were available.

Markcheese

"Generally these compressed air storage schemes are used in conjunction with gas turbines so the pressure would be the optimal pressure of a gas turbine."

Does that mean it provides an alternative power source for an existing gas turbine ?- and while decreasing the project cost this would reduce it's ability to be a "peaking plant" as, if the gas turbine it's attached to is already running ,it can't add more power to the grid -