Storing wind power in cold stores

[jpak]

http://blogs.zdnet.com/emergingtech/?p=486

According to Nature, a European-funded project has be launched to store gigawatts of electricity created from wind into the refrigerated warehouses normally used to store food. As the production of wind energy is variable every day, it cannot be easily accommodated on the electricity grid. So the "Night Wind" project wants to store wind energy produced at night in refrigerated warehouses and to release this energy during daytime peak hours. The first tests will be done in the Netherlands this year. And as the cold stores exist already, practically no extra cost should be needed to store as much as 50,000 megawatt-hours of energy.

Here is how Nature describes the — simple, but brilliant — idea behind this project...

The idea seems simple. Say you lowered the temperature of all large coldstores in Europe by just 1°C during the night when electricity demand is low, then let it rise 1°C by switching them off during the day when demand is at peak. The net effect would be that the warehouses would act as batteries — potentially storing 50,000 megawatt-hours of energy — and the food wouldn't melt.

Before going further, below is a diagram illustrating the idea: wind energy is optimally stored or released by following the electricity consumption patterns (Credit: Night Wind project)

In European jargon, the official denomination of the Night Wind project is "Grid Architecture for Wind Power Production with Energy Storage through load shifting in Refrigerated Warehouses." And it is led by Sietze van der Sluis, head of refrigeration and heating technology at The Netherlands Organization for Applied Scientific Research (TNO) in Delft.

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[Botany]

1. Great post

but in 'merica we don't cotton to that science stuff .....
it is based on evolution and abortions.

[zeemike]

2. What a clever idea. It makes sense n/t

[skids]

3. One wonders...

...what the round trip efficiency of freezing water and then using the water as a cold-side heat sink for another renewable source's heat pump would be, to boost the efficiency of energy extraction from, say, solar thermal. I don't feel like breaking out my calculator, though.

At any rate, there's also this for homes, where daytime cooling can use the ice most efficiently:

http://www.ice-energy.com/Default.aspx?tabid=61

[greenman3610]

4. this could also work for storing conventional

power, that is right now being wasted as "spinning reserve" at night, when
power usage is down.

freaking brilliant.
I will be using this in my
Climate Project showings...

[Dead_Parrot]

5. Dear God...

On what planet is this energy storage? It's a clever way of shifting the load, which is great, but I'd like to see someone run a light-bulb off it.

..."Store gigawatts of electricity"...

I swear, the more science reporting I read, the worse it gets. :(

[Ready4Change]

6. It can be useful.

They installed plants specificaly for this effect at a university I used to work at. They used to to "store" refridgeration during nighttime hours, when power rates were low. They used that cheaper power to freeze brine overnight. (They used brine as it has a lower freezing point than fresh water, allowing more cold storage.)

Then, during the daylight hours they would cool buildings by running refridgerant through that frozen brine, thus avoiding paying for more expensive peak hour power.

Saved them money, and shifted power requirements from peak hours to less demanding hours, thus making better use of existing power capacity.

Now, as for using that cold storage to DIRECTLY light lightbulbs, I'll let people knowledgable about things like sterling engines make some suggestions.

[Dead_Parrot]

8. Yes, you could use a cold mass with a stirling engine...

...using the external air temperature as a "heat" source. But they're not doing that here, they're 'just' time-shifting the refrigeration. It's certainly useful, but with an EROEI of exactly zero, I think calling it "energy storage" is rather euphemistic and a bit misleading.

You could call it "cold storage", but I don't think people would get very excited about storing cold in a cold store. :silly:

As a side note, this is how old-fashioned ice-houses worked (albeit on a 12-month cycle). Another technology we've had for thousands for years and forgotten, only to realise that it was actually a damn good idea...

[Porcupine]

7. Here's a retail unit for home use.

http://www.ice-energy.com/Default.aspx?tabid=66

Ice Bear® 50 - Residential
Ice Storage Air-conditioner

A residential version of Ice Energy’s® popular Ice Bear® 50 Unit, initially a hit in commercial markets, can now be applied to custom and larger semi-custom homes. The residential Ice Bear® 50 module is an off-the-shelf product that “plugs-into” standard air-conditioning systems. The storage module is charged by a standard 5-Ton condensing unit at night, when it’s cool, and the condenser’s efficiency is at its highest. An Ice Bear® 50 module stores 50 Ton-hours of cooling capacity, roughly equal to running a 5-Ton unit continuously for 10 hours. On the hottest days, a condensing unit’s ability to cool decreases dramatically. In contrast, the Ice Bear® system’s ability to cool is unaffected by ambient temperature. On the hottest days of the year, homeowners will enjoy rapid draw down of indoor temperature and up to 7.5 Tons of consistent “ice powered” cooling. All this while only using the power required to run two 150 watt light bulbs: An Energy Efficiency Ratio (EER) of 300. Homeowners can feel good about being cool as every two Ice Bear® 50 units installed have the environmental impact of removing one car’s emissions from the air.

It looks a little larger than a standard home AC compressor. It would not be as efficeint as a geo-exchange unit but probably a cheaper install.

[eppur_se_muova]

9. Storing energy by storing ice is a very old idea.

http://www.energy.rochester.edu/storage/icetes.htm

It's getting a lot more attention lately, for reasons easy to guess.