Compressed Air Energy Storage
It’s good to see that Compressed Air Energy Storage (CAES) is still in the news. Though it’s been around for decades, it hasn’t enjoyed successful commercialization, but perhaps that’s about to change.
There are issues with cases associated with physics that limit the utility of CAES, namely the topography of the cavern and the adiabatic heating and cooling associated with charging and discharging. Having said that, both these issues can be mitigated with good engineering.
2GreenEnergy is still trying to find a source of funding for the CAES project described here, and we’ve come close with a number of potential investors; I continue to feel we’re knockin’ on the door.
Craig,
Good for you! For every project, maybe there’s investors eager to take up the challenge and risk.
However, I would imagine without government backing and financial incentives such facilities would only be economic in very few locations with the right geological formations.
The holding costs on construction and approvals would be very onerous and risky and rely on energy pricing remaining viable.
Not an easy project, but I wish you the best of luck.
Craig here are your comments from 6th April 2012 when being interviewed by Mathius (Energy Informative. https://energyinformative.org/grid-energy-storage-craig-shields-interview/
Mathius: Q. What do you think are the most promising technologies to store utility-scale energy at this time?
Craig A. Similarly, I’m not a huge believer in compressed air (CAES). There are two implementations of this technology on the planet today and I think there is a reason for that. The choice of caverns is very specific for the rate at which you need to charge and discharge. You pay a huge penalty in terms of thermodynamic efficiency if you have the wrong cavern for what you’re doing. The world does need more implementation and testing of this technology, but I’m not sure if it will be a good long-term solution.
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And we have discussed this in a previous 2greenenergy blog: https://www.2greenenergy.com/2017/10/09/energy-storage-2/ where I commented:
Lawrence Coomber says:
October 23, 2017 at 12:51 am @Craig
At the small to medium scale, conventional hydro kinetic energy storage that is able to reliably; permanently, and cost effectively exploit the two ‘freebies’ of (rainwater catchment and gravity); place this form of generation potential at the head of all others given that the geographical ‘must haves’ all line up.
Outside of that though (at the utility scale) battery storage is only viable in a capacitive role in stabilising the grid, and compressed gas type generation is not a serious technology in any utility-based scenario looking forward.
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And nothing since has changed regarding CAES. This seems to be one of the rare moments where you and I seem to have expressed similar comments on something Craig! LOL. One of us by calculation and experience the other by guess work though I expect.
To the best of my knowledge going back a bit; there are a couple of large scale CAES systems in service. The first large scale one was in Spain I recall, and another was installed in Shandong Province China that I know very well because I was a member of the inverter commissioning team for that dual source hybrid power plant project in 2016 (15 MW Solar PV plus about 10 MW of CAES).
It was stage 1 of 3 stages planned for a 48 MW industrial power plant and the first stage was all rooftop PV and ground mounted CAES.
Stage 1 was completed and that’s where the project stopped dead in its tracks. Forever. Why? Well the old chestnut became starkly apparent post commissioning; in a nutshell, commercial reality simply did not stack up – ex post facto of course, because that’s how things operate globally in this sector.
Now where have we heard that unfortunate lament before? Certainly never from our old mate Bill Nye the Solar guy.
Whilst it was impressive to be a part of the CAES inverter installation team (over 2000 tonne of steel in the 15 air jars alone (air jars is a Chinese description) I prefer air cylinders; it was apparent knowing the project figures and the engineering science behind it all, that it was ultimately another global renewable energy fantasy bubble of the time, paid for by taxpayer funds (yes China has taxpayers just like in California) and with zero percent of competitive edge about it, no matter how one distorted and manipulated the technological commercial realities attached to the installation.
But despite the facts about the science of CAES (which can never change – the immutable laws of thermo-dynamics teach us this) South Australia is stuck in another fantasy bubble along the same lines in 2019 but at an even bigger scale by many multiples, that is now at the $30 million pilot stage.
God help us.
The 30 million will be spent; and the project will be suspended at that point; money gone. Now who could have imagined that a project like that could fail?
I have some interesting stories and photos of those mighty 15 (CAES air jars). They rolled in one by one on huge low loaders from Dalian, which is the major ship building town in China. Painted shiny pacific blue and they looked amazing when installed side by side in a single purpose-built huge hanger, and being a 20-year naval veteran, I thought I had seen them all before but in another role perhaps?
And I was right as it turned out.
They were effectively adapted submarine hull designs from a submarine builder in Dalian.
So once again Craig, let’s all pause at this point; take a deep breath and agree to finally sign off on CAES once and for all as “another great idea – funded by the taxpayer – that on reflection surprisingly didn’t quite cut the mustard”.
CAES – RIP
Lawrence Coomber
Craig it is worth me commenting a bit more on Pico Scale CAES, which I have been involved in directly and we have implemented this concept in one of our small scale rural Off Grid solutions on a farm near Canberra.
The key features of Pico Scale CAES are its reliability and longevity and low cost to integrate.
It is suitable for Off Grid solutions to around the 25 KW of Solar PV size, and rather than using miniature submarines as the air jars, the appropriate number (sized for the system) of upturned standard G size steel acetylene gas bottles (< $40 each from manufacturer) were our design, connected together by a manifold, which drives a compressed air motor and coupled DC alternator. It works a treat and is extremely reliable and cost effective.
It is not an efficient system from an engineering standpoint, but at the practical level a very cost effective enduring solution at Pico scale.
Lawrence Coomber