Batteries To Store Wind Energy 275
Roland Piquepaille writes "Scientific American reports that Xcel Energy, a Minneapolis-based utility company, has started to test a new technology to store wind energy in batteries. The company is currently trying it in a 1,100 megawatt facility of wind turbines in Southern Minnesota. The company started this effort because 'the wind doesn't always blow and, even worse, it often blows strongest when people aren't using much electricity, like late at night.' It has received a $1 million grant from Minnesota's Renewable Development Fund and the energy plant should be operational (PDF) in the first quarter of 2009. If this project is successful, the utility expects to deploy many more energy plants before 2020 to avoid more polluting energy sources."
I'd want to store it in a hydro tank... (Score:3, Interesting)
I'd pump water UP to store the energy and let it flow DOWN to release the energy.
Granted it might not be as efficient as battery storage but it would be cheap, deploy-able right now, and it can be made as large as needed, plus it can be used to extinguish fires "downhill' and slake thirst.
It doesn't even have to be in the same place as the wind farm. Just in front of it, like in the mountains like the ones that cause the chinooks winds in Alberta.
I can see setting up a mountain top reservoir, filling it with water pumped by excess energy and emptying it when needed.
Re:a dam sounds like a pretty good battery to me (Score:5, Interesting)
The best places for wind turbines (open plains) are usually far away from the best places for dams (canyons). The increased cost of building transmission lines and increased losses on those lines makes your solution impractical for most locations. A few exceptions may exist, but most "wind alley" locations like TX, OK, and IA don't have the elevation changes needed for hydropower.
Store the energy in a massive weight (Score:5, Interesting)
Re:I'd want to store it in a hydro tank... (Score:3, Interesting)
They do this off the Grand Coulee Dam. But they are hardly ever used, as they are only really needed when there is need for flood control, AND lack of Power Need.
There already exist these giant "batteries" and couldn't the power be utilized for things like this, rather than something new?
There seem to be a ton of places where one could use excess energy at night, that you wouldn't need a new "Battery" source.
Re:Seems silly to use this. (Score:5, Interesting)
I remember that flywheels were considered for electric cars as well.
Some of the issues I remember off hand were:
1. Specialized materials needed to build flywheels that are small, yet heavy enough to keep spinning for a long enough time after being "charged"
2. Getting the energy IN the flywheels in the first place - it takes more energy to get them spinning than what you draw from them.
3. Given the high velocities - what will happen when they fly apart? Also, the gyroscopic effects they generate while spinning.
4. The heavy mounts needed to safely position them negated any advantages through increased weight.
I don't know if any of these apply to stationary flywheels built into power plants though...
Re:I'd want to store it in a hydro tank... (Score:5, Interesting)
Selling a few million plug-in hybrids should help quite a bit.
It would be even better if those cars were on the Internet so they could talk to the power company. For instance if I tell my car to be charged by 8am the next day, it could negotiate with the power company to draw power whenever it is cheapest.
Re:I'd want to store it in a hydro tank... (Score:3, Interesting)
I know there's been some consideration to storing energy in freezers. It's not technically storing, it's more like shifting power draw from peak to off peak times allowing for the capacity to be more efficiently used.
Basically with refrigerated warehouses being set a few degrees colder off peak and being allowed to warm subtly during peak. It's always below the necessary temperature, but the cooling system is off during large chunks of the peak consumption hours.
Wind/Water Reservoirs (Score:3, Interesting)
In the wind alley, they do a lot of farming, right? Why not create two level reservoirs, one a hundred and fifty feet higher than the other, and then when there is excess production, you pump the lower reservoir into the higher one. Even better, find some underground features that would make it easy to create underground reservoirs with different elevations. And if you hit a hot spot of granite, even better - redirect the steam so it spins some turbines.
Drought presents problems to open air reservoirs. It may actually be cheaper to use superconducting transmission lines to somewhere with better natural features.
If WalMart and Sams Club covered all of the parking lots with solar panels, not only would they reduce localized heat effects, it would probably be enough to power all air conditioning in the south during those hot sunny days. I don't know why any sprawl areas are looking for huge plots of lands to stick solar powered plants on. They have hundreds of square miles of parking lots already, they just need to be leased from the malls and stores.
But, as always, the best way to save energy is still conservation. It's 100% effective and free. Unfortunately there's no profit in efficiency, and thus it's not a political option.
Re:Seems silly to use this. (Score:4, Interesting)
I heard a story of a datacenter in California doing this for backup power. The center was powered off of the mains, and also had a large (20ft or so) flywheel kept running. If the power cut, the flywheel powered the necessary systems for the minute or so it took the generators to start up.
Seemed ingenious to me.
Re:Wind/Water Reservoirs (Score:1, Interesting)
Conservation is a stop gap at best. Unless you are planning on stopping worldwide population growth, and killing a large percentage of the worlds existing population, conservation is just a way to feel good about yourself while ignoring the actual problem. Society crippling conservation would only push the problem off on to our grandchildren instead of making our children deal with it.
Re:a dam sounds like a pretty good battery to me (Score:2, Interesting)
Re:Seems silly to use this. (Score:3, Interesting)
Actually, a few Formula 1 teams are adopting a flywheel solution to implement KERS (Kinetic Energery Recovery System) for the upcoming 2009 season.
http://www.greencarcongress.com/2007/11/second-major-f1.html [greencarcongress.com]
From memory, BMW and Ferrari have opted for different technology though.
Re:Seems silly to use this. (Score:3, Interesting)
Other advantages of being stationary are that you can afford the space/weight to add additional infrastructure which you would never fit in a vehicle.
For instance:
- you could try building it in a near-vaccuum or at least low-pressure chamber to make air resistance negligible
- the heavy and complex equipment needed for extremely low friction bearings (or even something frictionless) could be much more easily constructed on land
For some reason I love flywheels. They're just so much more elegant than chemical energy storage.
Re:Seems silly to use this. (Score:5, Interesting)
Re:Seems silly to use this. (Score:3, Interesting)
A good flywheel will be suspended by magnets, so regardless of the weight, the friction due to weight is effectively zero. There is still air friction and electrical losses to deal with.
Put the flywheel in a permanently-sealed vacuum chamber. Accelerate and decelerate it with magnetic fields as well. Effectively it's a large electric motor that accelerates the flywheel when you feed power into it and a generator that decelerates the flywheel when you put a load on it.
Re:How efficient? (Score:3, Interesting)
The sodium-sulfur [wikipedia.org] batteries they are using are apparently 89-92% efficient (efficiency should increase with scale - these batteries must be kept at a temperature of about 300C and because of the square-cube law [wikipedia.org] it's much easier to keep very big things hot). Large (>100kW) fully-inverting UPSs are often 94% [mgeups.com] efficient - the rectification/inversion needed for this could be similarly efficient.
Re:Seems silly to use this. (Score:3, Interesting)
Re:How about Hydrogen (Score:3, Interesting)
With standard PWR's and BWR's, the coolant is the moderator and any increase in voids will reduce reactivity. This would be especially true for the AP-1000 at the beginning of core life.
As for containment, I have heard no plans to reduce containment to the levels of the RBMK-1000's - at least in the US. Containment design prior to TMI was predicated on an radio-iodine release several orders of magnitude higher than is likely to happen from a loss of coolant accident.
Compressed Air Energy Storage to Store Wind Energy (Score:2, Interesting)
Compressed air is another means of storing wind energy that is getting looked at again. The CAES schemes need large geological structures such as salt mines or depleted gas fields, but there are quite a lot of viable structures in places like Texas and Ontario where there is also interest in wind energy. It is not economical on a small scale since a large part of the compression cost is independent of the reservoir size.
According to the US Department of Energy "nearly two-thirds of the natural gas in a conventional power plant is consumed by a typical natural gas turbine because the gas is used to drive the machine's compressor. In contrast, a compressed-air storage plant uses low-cost heated compressed air to power the turbines and create off-peak electricity, conserving some natural gas."
In the last 20 years only two facilities have ever been built - a 110-megawatt plant in Alabama and a 290-megawatt plant in Germany. Iowa is building a new plant "expected to cost $200 million and operate by 2011 with the capacity to store 200 megawatts of power, enough for several days. Both the Iowa and Alabama installations can draw air to make power within 15 minutes and make a gas turbine roughly 40 percent more efficient. "
http://www.eere.energy.gov/de/compressed_air.html [energy.gov]
http://arstechnica.com/news.ars/post/20081224-full-of-powerful-wind-bury-it-in-the-ground-for-later.html [arstechnica.com]
http://www.thestar.com/business/article/553702 [thestar.com]
http://www.isepa.com/index.asp [isepa.com] Iowa Stored Energy Park
http://news.zdnet.com/2100-9595_22-178929.html [zdnet.com]