Storing Renewable Energy in Boxes of Air

November 20th, 2009 by Susan Kraemer

Storage is needed to harvest the full yield available from intermittent sources of energy like wind and solar. One of the options is compressed-air storage; till now only possible in underground caverns. But SustainX Energy Solutions; a Dartmouth College start-up that got $4 million in VC funding from Polaris Venture Partners and Rockport Capital this year is working on compressing and storing air in cheap off-the-shelf shipping containers.

Over the next two years SustainX will try to develop a way to cram 4 megawatt-hours worth of stored energy into each 40-foot long container and to reduce the energy that it currently takes to compress and release air by about 70%.

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The goal? A renewable energy storage system with the portability and scalability of a battery and the economy and capacity of a cave. Make that a portable cave.

Cheap storage is needed. A lot of research dollars are going into building a variety of storage options for renewable energy to extend their contribution to the grid. We have too much wind at night and too much solar in the day: but seldom overlapping in any one region.

The breakthrough better battery is being funded by ARPA-E and sought by hundreds of researchers and companies from the traditional fly-wheel manufacturers to new nanotech start-ups.

Utilities are looking into storing energy in compressed-air in caves, in gravity; by pumping water up – to let it drop when needed – or in rolling batteries; by loading up extra juice at night into electric cars – to be dispatchable back to the grid again at peak with interactive vehicle-to-grid technology.

PG&E is one public utility scouting for caves suitable for compressed-air storage capable of storing 3,000 megawatt-hours (or 300 megawatts for ten hours). There are already a few compressed-air facilities in the world where off-peak electricity is used to pump air underground for storage. During peak-demand times, the air is released and pushed through a turbine to make electricity. Utility-scale battery storage systems only deliver 1 or 2 megawatts for a few hours.

But underground limestone caverns aren’t always right where you need them; at least with the right geological attributes that make them safe as depositories. You need the portability and scalability of a battery and the economy and capacity of a geological feature.

The president of SustainX; Dax Kepshire conceived his modular scalable portable “cave” system to find that solution. Portable compressed air storage could be big simply because it is a very cheap tech. Even more so now, since Dan’s portable “caves” could be the unused shipping containers that are piling up in ports around the world.

Related stories:

Pump Hydro Underground to Store Wind

For Energy Storage Cheaper than Fossil Fuels – CAES

Image:SustainX

Source:Greentech

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Tags: 40-foot long container, off-peak electricity, Polaris Venture Partners, renewable energy storage, Rockport Capital, SustainX Energy Solutions

About the Author

Susan Kraemer writes at CleanTechnica, CSP-Today, PV-Insider , SmartGridUpdate, and GreenProphet. She has also been published at Ecoseed, NRDC OnEarth, MatterNetwork, Celsius, EnergyNow, and Scientific American. As a former serial entrepreneur in product design, Susan brings an innovator's perspective on inventing a carbon-constrained civilization: If necessity is the mother of invention, solving climate change is the mother of all necessities! As a lover of history and sci-fi, she enjoys chronicling the strange future we are creating in these interesting times. Follow Susan on Twitter @dotcommodity.

Susan Kraemer

@Chris and Mathew: Just for you guys: some cleantechnica geo news from the mists of time…..

http://cleantechnica.com/2009/11/16/using-co2-to-extract-geothermal-energy/

http://cleantechnica.com/2009/11/10/biggest-public-utility-in-us-exploring-geothermal-energy-to-help-ramp-up-to-40-by-2020/

http://cleantechnica.com/2009/10/11/ormat-supplies-recovered-energy-generation-to-doe-oilfield/

http://cleantechnica.com/2009/10/04/doe-introduces-big-oil-to-new-energy-source-waste-heat-geothermal/
Susan Kraemer

@Chris and Mathew: Just for you guys: some cleantechnica geo news from the mists of time…..

http://cleantechnica.com/2009/11/16/using-co2-to-extract-geothermal-energy/

http://cleantechnica.com/2009/11/10/biggest-public-utility-in-us-exploring-geothermal-energy-to-help-ramp-up-to-40-by-2020/

http://cleantechnica.com/2009/10/11/ormat-supplies-recovered-energy-generation-to-doe-oilfield/

http://cleantechnica.com/2009/10/04/doe-introduces-big-oil-to-new-energy-source-waste-heat-geothermal/
Susan Kraemer

@Chris and Mathew: Just for you guys: some cleantechnica geo news from the mists of time…..

http://cleantechnica.com/2009/11/16/using-co2-to-extract-geothermal-energy/

http://cleantechnica.com/2009/11/10/biggest-public-utility-in-us-exploring-geothermal-energy-to-help-ramp-up-to-40-by-2020/

http://cleantechnica.com/2009/10/11/ormat-supplies-recovered-energy-generation-to-doe-oilfield/

http://cleantechnica.com/2009/10/04/doe-introduces-big-oil-to-new-energy-source-waste-heat-geothermal/
http://www.britesprite.co.uk Chris Milton

@Matthew Excellent point .. why isn’t geothermal being pursued more?? Or is it *because* “There is no need to store anything … and you can put that anywhere … so you wouldn’t need to build the transmission lines either”
http://www.britesprite.co.uk Chris Milton

@Matthew Excellent point .. why isn’t geothermal being pursued more?? Or is it *because* “There is no need to store anything … and you can put that anywhere … so you wouldn’t need to build the transmission lines either”
The Trutherizer

@quixote You say measures to get our dependency on fossil fuels must be… fashionably pretty? Get real please. lol I don’t care if it’s ugly, stinks or and/or has really bad manners. As long as it works.
The Trutherizer

@quixote You say measures to get our dependency on fossil fuels must be… fashionably pretty? Get real please. lol I don’t care if it’s ugly, stinks or and/or has really bad manners. As long as it works.
The Trutherizer

@quixote You say measures to get our dependency on fossil fuels must be… fashionably pretty? Get real please. lol I don’t care if it’s ugly, stinks or and/or has really bad manners. As long as it works.
Susan Kraemer

There are some fascinating comments on the technicalities and cost calculations at

http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=115×217945#217952
Susan Kraemer

There are some fascinating comments on the technicalities and cost calculations at

http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=115×217945#217952
Michaelc

If this concept actually works it is brilliant. There are lots of empty shipping containers available cheap, we already have dedicated tools for handling and transporting them, and they even stack well.
Michaelc

If this concept actually works it is brilliant. There are lots of empty shipping containers available cheap, we already have dedicated tools for handling and transporting them, and they even stack well.
Michaelc

If this concept actually works it is brilliant. There are lots of empty shipping containers available cheap, we already have dedicated tools for handling and transporting them, and they even stack well.
john galt

Compressed air is easy, but not very efficient. If it doesn’t break even or make money, it’s not likely to prevail. Still, it’s so simple, even a caveman could do it. The answers are out there, but how do we stay on the straight line toward them? I think what everyone is most concerned about is how they are going to get from point A to B. Transportation fuel is paramount in America. For now, the Ram says his “tank is full”.

I would hope that if we can reduce the use of coal for electricity, then that coal could be redirected over to methanol or Di methyl ether, two economically competitive fuels that people could adapt to without much fanfare. It could even be cheap enough to keep us in smooth-riding 5000 pound American made vehicles. But for now, protecting the sea lanes and policing the world can be paid for by the unborn, so petroleum is still king of the hill.

Here’s a batch of interesting reading.

http://www.alternatefuelsworld.com/
john galt

Compressed air is easy, but not very efficient. If it doesn’t break even or make money, it’s not likely to prevail. Still, it’s so simple, even a caveman could do it. The answers are out there, but how do we stay on the straight line toward them? I think what everyone is most concerned about is how they are going to get from point A to B. Transportation fuel is paramount in America. For now, the Ram says his “tank is full”.

I would hope that if we can reduce the use of coal for electricity, then that coal could be redirected over to methanol or Di methyl ether, two economically competitive fuels that people could adapt to without much fanfare. It could even be cheap enough to keep us in smooth-riding 5000 pound American made vehicles. But for now, protecting the sea lanes and policing the world can be paid for by the unborn, so petroleum is still king of the hill.

Here’s a batch of interesting reading.

http://www.alternatefuelsworld.com/
john galt

Compressed air is easy, but not very efficient. If it doesn’t break even or make money, it’s not likely to prevail. Still, it’s so simple, even a caveman could do it. The answers are out there, but how do we stay on the straight line toward them? I think what everyone is most concerned about is how they are going to get from point A to B. Transportation fuel is paramount in America. For now, the Ram says his “tank is full”.

I would hope that if we can reduce the use of coal for electricity, then that coal could be redirected over to methanol or Di methyl ether, two economically competitive fuels that people could adapt to without much fanfare. It could even be cheap enough to keep us in smooth-riding 5000 pound American made vehicles. But for now, protecting the sea lanes and policing the world can be paid for by the unborn, so petroleum is still king of the hill.

Here’s a batch of interesting reading.

http://www.alternatefuelsworld.com/
Matthew

Why isn’t enhanced Geothermal being used as a first renewable energy source? That runs 24 hours a day 7 days a week, through night, though lack of wind, etc etc.?

There is no need to store anything when you use enhanced Geothermal and you can put that anywhere in the US, and right next to where the electricity is needed so you wouldn’t need to build the transmission lines either! Another huge win!
Matthew

Why isn’t enhanced Geothermal being used as a first renewable energy source? That runs 24 hours a day 7 days a week, through night, though lack of wind, etc etc.?

There is no need to store anything when you use enhanced Geothermal and you can put that anywhere in the US, and right next to where the electricity is needed so you wouldn’t need to build the transmission lines either! Another huge win!
Matthew

Why isn’t enhanced Geothermal being used as a first renewable energy source? That runs 24 hours a day 7 days a week, through night, though lack of wind, etc etc.?

There is no need to store anything when you use enhanced Geothermal and you can put that anywhere in the US, and right next to where the electricity is needed so you wouldn’t need to build the transmission lines either! Another huge win!
Susan Kraemer

@quixote – same thought: I was loathe to even use the image, it was so ugly. Finally had to because I could not find any other illustration of the idea.
http://www.molvray.com/acid-test/ quixote

Great idea, but . . . so-o-o ugly! They need to hire an artist to come up with a way of making the “package” more visually interesting. Otherwise there’ll be a big NIMBY factor.
http://www.molvray.com/acid-test/ quixote

Great idea, but . . . so-o-o ugly! They need to hire an artist to come up with a way of making the “package” more visually interesting. Otherwise there’ll be a big NIMBY factor.
http://www.molvray.com/acid-test/ quixote

Great idea, but . . . so-o-o ugly! They need to hire an artist to come up with a way of making the “package” more visually interesting. Otherwise there’ll be a big NIMBY factor.
Susan Kraemer

@quixote – same thought: I was loathe to even use the image, it was so ugly. Finally had to because I could not find any other illustration of the idea.
http://extremegreenvillage.com Bob

I know I am missing something but if you compress air into a rectangular box won’t it deform into being the shape of cylinder? That’s why compressed gases are stored in spherical and cylinder shapes.
http://extremegreenvillage.com Bob

I know I am missing something but if you compress air into a rectangular box won’t it deform into being the shape of cylinder? That’s why compressed gases are stored in spherical and cylinder shapes.
http://extremegreenvillage.com Bob

I know I am missing something but if you compress air into a rectangular box won’t it deform into being the shape of cylinder? That’s why compressed gases are stored in spherical and cylinder shapes.