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Storage System

09/16/2014 2:45 PM
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#1

Re: storage system

09/16/2014 5:11 PM

Well, it would work. Don't know what the losses will be.

But, What is the ROI?

What is the pay-off period?

Will this make the electricity more expensive?

What about construction and maintenance costs of the added storage system?

Is the additional wear/shortening of life of the wind generators justified? Now the blades are feathered and the generators stop. No wear.

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#9
In reply to #1

Re: storage system

09/17/2014 5:24 AM

Hydrostore claim that with the addition of the heat storage the efficieny is up to 80% which is about the same as pumped hydro storage. But I doubt that they can compress air, even recovering the waste heat, for the same price as they could pump water up a hill. Water is stored in a lake (comes free) or a dam across a hanging valley (cheap to make and maintain), both of which options must be cheaper than accumulators. Piping would be on a par but pumps are cheaper than compressors, both to buy and maintain. As far as I can tell they only have one pilot scheme working at present and that runs at 1MW rather than the 30MW systems they propose as an optimum. The figures they are releasing at present are shrouded in commercial confidentiality clauses while they tout for backers to put a full scale system into operation. An alternative to solid accumulators is a corrugated inflatable balloon that stores the compressed air. That system has the advantage that it is ship launched without the use of divers to instal. You need about 100m of water to make the numbers add up but if you don't have a handy 100m mountain with a lake at the top, or if evaporation from your storage is a big problem, then this system could make sense.

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#12
In reply to #9

Re: storage system

09/17/2014 9:21 AM

My thoughts, also.

We had a pumped storage system on one of our lakes on the Verde River here in AZ for years. It seemed to me to be quite a simple way to produce energy during peak demand and then, produce potential energy during off peak times.

It's been decommissioned, not sure why.

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#2

Re: storage system

09/16/2014 5:22 PM

Most of the energy is heat of compression. So just how are they trivially storing this?

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

Remember the "air car" a few years ago that a French inventor was proposing? I researched this subject then and found there were commercial attempts. The heat of compression is a big issue to overcome. You either waist it, or figure out a high temperature storage method.

Maybe they figured out a storage method, but their video does not show the true size.

The wiki article referenced the German salt mine operation in 1978. Memory of this was they used natural gas to reheat the compressed air during expansion. They discarded the heat of compression as it would melt the salt.

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#3
In reply to #2

Re: storage system

09/16/2014 5:47 PM
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#4
In reply to #3

Re: storage system

09/16/2014 6:30 PM

That might be a smart way to use the waist heat of the ICE. It's my dislike of hybrids as there are 2 systems. But my instincts think the air expansion engine is simpler then an electric storage-battery-motor system. Still need a cheep source of compressed air.

I wish they still made 1987 Chevy Sprints (Suzuki Justi).

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#5
In reply to #4

Re: storage system

09/16/2014 6:57 PM
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#6
In reply to #5

Re: storage system

09/16/2014 9:30 PM

117MPG WOW!

This is a practical way to use stored compressed air, and to charge the accumulator with brakes.

I didn't see a sticker price, or when it would be production/exported. I'm not one to do green for the sake of green without there being $ payback.

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#11
In reply to #6

Re: storage system

09/17/2014 7:55 AM

waste not waist

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#13
In reply to #11

Re: storage system

09/17/2014 10:23 AM

It was #4, not #6

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#7

Re: Storage System

09/17/2014 12:24 AM

What happens when somebody is fishing and hooks into one of those balloons and rips a big hole in it while reeling in the "big one"..??

...maybe they could make the balloons look like fish.....freak any divers

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#8
In reply to #7

Re: Storage System

09/17/2014 5:19 AM

These energy storage systems for electric grid operation are in the 45 to 70 Bar ~1000psi (max). Those balloons need to be 2200 feet below the surface for this pressure.

Lake Ontario where they are experimenting is 800ft max, 280ft nominal.

They need volume storage of ~150,000 cubic meters, to be useful (or similar to existing designs).

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Power-User

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#10

Re: Storage System

09/17/2014 5:45 AM

In principle this looks a viable way of storing energy. But:-

What sort of volume of storage would you thing would be needed to make this a feasible solution to a global energy problem?

If the volume needed is massive, would this effect the sea levels?

It's well known that the generation of compressed air is very expensive and inefficient. So would this be the best use of excess energy?

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#15
In reply to #10

Re: Storage System

09/17/2014 12:22 PM

I'm not sure about the global aspect but lead/acid or lithium are too small and expensive. we could really use something large like these for all the missed opportunities to harvest while the sun shines and the wind blows. so much is wasted now with no attempts to store It.

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Power-User

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#16
In reply to #15

Re: Storage System

09/18/2014 2:58 AM

Have they generated a table of what volume of compressed air will generate how much power and for how long a sustained period. It just seems as if they're just proving a concept; which we all realise in theory will work; but there doesn't seem to be any hard and fast facts, which I would've thought would've been the first thing to get down on paper before committing any finances. I suppose we could sit down and do the maths ourselves, to get a rough estimate, but you'd think these guys would've done that, for an extra selling point. Or is it not that much of a selling point.

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#14

Re: Storage System

09/17/2014 12:08 PM

One of 2 ways currently being developed. Not sure of the economics of this way but there have been a couple of "flywheel" storage facilities recently commissioned in Ontario, Canada. Can't recall how many MW they were, but I think they show a little more promise.

Have also heard of storing the compressed air in caverns in the earth, similar to how natural gas is stored in large quantities today. Same principal, just different storage method.

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Anonymous Poster (1); DodgySolenoid (2); Fredski (3); ignator (4); jhhassociates (1); Kevin LaPaire (1); lyn (2); SolarEagle (1); StandardsGuy (1)

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