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Batteries To Store Wind Energy
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 hope it's not 9 volt. Those are hard to find.
Why are more utilitys not using something like what beacon power is doing.
Storing energy in flywheels. Spin it up when the wind blows. Draw it off when you need it. They last for a very long time when compared to batterys.
Batterys are kind of high priced for a low lifetime. Require all kinds of nasty chemicals to make and need to be disposed of someday. And take HUGE banks to store what a large flywheel would store.
Seems silly...
i believe some dams release water through the turbines during peak times, then pump it back up off peak at night with excess cheap electricity ready for the next day, is that not a reasonable form of energy storage? i imagine a similar level of energy storage in anything recognisable as a battery would be insanely expensive and/or involve alot of toxic chemicals
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.
MSBPodcast.com The opinions expressed here are my own. If you don't like 'em... Think up your own stuff.
sounds like a cool potential battery technology too. The battery element determines the power, and the amount of energy storage is only limited by the size of the tanks.
http://discovermagazine.com/2008/oct/29-the-element-that-could-change-the-world/
thegodmovie.com - watch it
I don't know if this is feasible but I've always thought that a mechanical solution would be better. Use the excess energy to lift a huge weight like the weights on a pendulum clock. When the wind dies down, just let the weight power a generator. Assuming concrete is reasonably environmentally friendly this would be a pretty clean solution.
The difference between Canada and the USA is that in Canada healthcare is a right and gun ownership is a privilege.
Some sort of cylindrical container for holding liquids one intends to imbibe?
You'd better patent that before someone else does.
Why concrete? Cement is ridiculously energy intensive to produce. Why not stick with water, or if you really want something more complicated to handle but heavier, go with good ol' rock. We'll need to conserver all the cement and steel that we can in the coming years.
I like my dinosaurs feathery, and my pterosaurs hairy (or is it pycnofibery?)
Capacitors, at least the few I have seen, generally want to release their stored energy all at once. How is this addressed when supercapacitors are used? For example, let's say you have a supercapacitor that can power a light bulb for eight hours. How do you make it actually provide a lower current over those eight hours instead of providing all of that energy in a single instant and frying the bulb?
By understanding I=V/R.
A capacitor has a certain voltage (whatever you charged it to) and an internal resistance. The load (light bulb) you attach also has a certain resistance. The discharge rate is determined by those two resistances (added together) and the voltage. The "all at once" just means that the internal resistance is almost zero, so if you connect a load that also has zero resistance the capacitor will discharge very quickly. If your load doesn't have near-zero resistance, there won't be any real difference from using a battery.
1,100 megawatts, eh? Why, that's almost 1.21 gigawatts! Now we just need to come up with a flux capacitor and find an old Delorian!
The only way to tell the difference between a hamster and a gerbil is that the hamster has more white meat.
As a sailor, I'm sure your maritime experience is vast. But... do you happen to know where Minnesota is? You might want to check a map... XD
"Convictions are more dangerous enemies of truth than lies."
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.
Yeah, but the comments here don't make me want to kill people.
I am so sick of science writers who mess up the story because they don't understand the units of energy and power.
The article says the batteries store 7 megawatt hours. Fine.
Then it goes on to say "meaning the 20 batteries are capable of delivering roughly one megawatt of electricity almost instantaneously" WTF does that mean? Power, measured in megawatts is by definition an instantaneous unit. What's with "almost instantaneous". Also, the rate of discharge of a battery MW is unrelated to its storage capacity MWh, so the entire meaning of the sentence makes no sense.
Then the article says, "Over 100 megawatts of this technology [is] deployed throughout the world," Huh? Battery capacity is measured in megawatt-hours, not megawatts.
Then the article says, "costing roughly $3 million per megawatt" same thing. Battery cost must be proportional to megawatt-hours, not megawatts.
I suspect that their idea is to make a battery with 24 megawatt-hours of capacity able to deliver 1 megawatt of power uniformly for 24 hours, then say so.
Shame on Sciam writers and double shame on Sciam editors for not mastering such basic units in an article about energy.
How about a little economics. The article mentions two understandable numbers, an 11 MW wind plant, and 7 MWh of battery capacity. The combination of the two, allowing for wind variations during the day believably deliver 1 MW continuously to the grid. That's 24 MWh per day.
Now the batteries cost $3 million, and the wind generators cost $22 million. Total $25 million to deliver 1 MW of base load. That's $25 billion per GW.
The peak generating capacity of North America is about 750 GW. Let's say 250 GW when levelized to base load. Therefore, to supply 100% of that with wind and batteries would cost roughly $6.2 trillion dollars. Now Al Gore says, "No problem. We can do that in just 10 years." WTF is he thinking?
Even if we did spend $6.2 T, there will still be periods where not much wind blows for large regions for many weeks at a time. I live where it's cold, and I know that when it hits -30F, the wind is almost always still and the sky dark, and that it can stay like that for a couple of weeks. We therefore, need to double or triple the $6.2T plus more for transmission, to provide backup power sources, plus the means of delivering the energy over large distances.
Wind and solar are wonderful for up to 15-1-20% of the total grid generation and the cost of construction and operations dominate. More than that, and reliability and deliverability of the electric supply become dominant in the economic equation.
Exactly, battery tech isn't economical yet. And it isn't improving anytime soon as batteries are pretty much at the end of their innovation (barring any major breakthrough). Similar to "how do you make a better wheel?" Batteries are the only solution in small setups, but I don't think they scale very well to really large systems.
Our current solution is to send it to the grid and pump water back up in hydroelectric plants. Wouldn't dedicated HVDC lines from solar/wind plants to hydro be a more economical alternative? Or build a local setup where you pump lots of liquid/weight up a height. It basically ends up being an ultra capacitor.
Hydrogen is a PAIN.
Hydrogen embrittlement makes storage and transportation a problem as does it's low density.
If you are going to make hydrogen you might as well take the next step and convert it to NH4 and use it for fertilizer or CH4 and use it for fuel. NH4 will also work as a fuel if you want. Both would work in a fuel cell or a gas turbine.
Of course Nuclear doesn't have these problems and if they would allow fuel reprocessing the storage problem would go away as well. As to safty modern western reactors have a great record. And any one that brings up the C word is just spreading FUD since it that disaster would never have been allowed to have been built in the US.
See my blog http://ilovecookes.blogspot.com/ for light hearted technical information.
So if a reactor is built in the US to today's abbreviated containment standards, yes, that reactor would include a failure mode similar to what occurred at Chernobyl.
The failure mode at Chernobyl was very specific to the design of the RBMK-1000 and to it being near the end of the core life. The problems at Chernobyl were that it had a positive coolant void coefficient, the reactor was burning Plutonium (delayed neutron fraction of 0.2% versus 0.65% for 235U), the graphite moderator was not thermally coupled to the fuel or coolant, and last but not least, the scram rods increased reactivity at their initial portion of travel - the Chernobyl accident was triggered by an operator scram'ing the reactor.
American light water reactors were design explicitly to have a negative coolant void and temperature coefficient.
FWIW, I do have a degree in nuclear engineering.
A Shadeless room is a brighter room.
The sodium-sulfur 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 it's much easier to keep very big things hot). Large (>100kW) fully-inverting UPSs are often 94% efficient - the rectification/inversion needed for this could be similarly efficient.
Pumped storage is cost effective. We currently do it with excess load on the power grid where turning off a coal plant would be too inefficient. We take extra power on the grid during non-peak times and run the hydro plants backward to store up potential energy behind the dams.
The problem seems to be routing that excess power from the source to the plants. Since HVDC lines are far more efficient, I was proposing building dedicated lines from fluctuating power sources (wind/solar/tidal) and storage (dams). Plus, with HVDC, you don't need to worry about varying voltage and frequencies like you would with AC.
By local setup, one option I can think of, if you have 2 lakes, you can pump water from a lower lake to a higher one. Another much smaller scale would be water towers. It just seems batteries are not the way to go for large scale storage.
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.
A Shadeless room is a brighter room.
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
http://arstechnica.com/news.ars/post/20081224-full-of-powerful-wind-bury-it-in-the-ground-for-later.html
http://www.thestar.com/business/article/553702
http://www.isepa.com/index.asp Iowa Stored Energy Park
http://news.zdnet.com/2100-9595_22-178929.html