DoE Invests In First Flywheel Power-Storage Plant

isaac knewton was a genius, flywheels are flippin awesome, and kinetic energy is a beast unto it's own. but really they should think about using magnetic springs to keep the stuff up then use a governor configuration to store more power in less space. basically the faster it spins the more the weights move outward the more they move outwards the slower it spins but the same energy is still there, thus creating more room to store more kinetic energy. saves a lot of time replacing worn out bearings since your storing energy in the position of the weight and not as much in the actual speed of it, and if you do it right you can have it drop another weight when the governor is outstretched to add even more space to store energy. just be sure to pick it up once the thing starts to slow down.

This article makes it sound like it can provide sustained power INSTEAD of natural gas turbines. Flywheels do not operate long enough to achieve this.

Zion, Illinois already uses a syncronous motor for reactive load balancing and has been doing so for years. It is operated by Exelon nuclear.

while the titles makes it sound that way the article clearly indicated that this is a device to solve fluctuations in the grid

@ghost
my thoughts exactly!

"Flywheels store electricity as kinetic energy, and can dispense that energy back to the grid in quick bursts. They have potential as energy storage devices for renewable energy sources, which are variable and unpredictable. Solar and wind power in particular would be more promising if there was a way to capture and store their energy for later use."

That makes it sound like you could store the power and use it later whenever you wanted. I don't think so, Tim.

@ SLNuke, the reason flywheels don't operate long enough to do that is because they are slowed down by mechanical friction in the bearings, and air friction on the flywheel itself. With this system, they are taking out both factors. It is stored in a drum evacuated of air, as close to solid vaccum as is possible with our current technology. The bearings consist of a magnetic levitation system which has zero measurable friction, thus allowing the system to theoreticaly be 100% efficient. The limmiting factor in the storage efficiency of the system will be in the motor/generator. Some of the electrical energy put into the system will be converted to heat by the motor, and some of the energy pulled out will do the same through the generator. But this system will lose absolutely miniscule amouts of energy throughout the storage period, effectively losing no energy at all for a day to day peak and valley draw that this system is being used for. If I understand the physics correctly, it should lose very little stored energy over long periods as well. So really, you could store and use it whenever.

@patron sing it brother! that's good that they're using magnetic bearings, kinetic energy is so great at storing energy because it can do it in almost any condition and any temperature, and done right might actually flourish as a way to store energy during space travel! and hey want gravity? just hook it up for a minute to the chassis that'll get things turning!

You're not understanding what I'm getting at. I don't care even if it could spin without friction (which is impossible but besides my point). It is not a solution to energy storage for peak shaving. It is not a sustained energy source and can not replace anything. It is, however, a good response to frequency regulation which can save everyone money. I just don't want people confused on it's purpose.

I wonder how much energy it takes to maintain the vacuum.

"...plant will buffer 20 megawatts of power on the grid"
Without more info that's completely useless information.

The cnet article says 200 of them can store about 15 minutes' worth energy at 20MW. Beacon power's website says one flywheel will store 25 kWh; 200 of them would be 4MWh. At 20MW that's not even 15 mins.

It would take massive installment of them to make it usable for solar/wind storage, since their fluctuations are far more than 15 mins. When we are talking about gigawatt scale storage, this will make for an enormous and spectacularly expensive facility.

@Patron, no, the limiting factor is tensile strength divided by density. With current state of the art fused sillica materials you can get up to almost 1 MJ per kg of flywheel material(does not include the vacuum vessel). This is useful for power conditioning on the grid and for replacing lead-acid batteries for backup power at data centers. It probably needs to be better than this to compete with lithium ion batteries for use in vehicles of various kinds.

The speed at the surface of the flywheel is mach ~4. You need a fairly hefty vessel to prevent the flywheel from being a bomb if it fails. It's not clear that increasing the energy density of the flywheel itself will increase overall energy density in vehicles. For stationary uses you just cover the flywheel with enough dirt or behind enough concrete and you're good to go.

If you had access to a flywheel made out of carbon nanotubes with a similar quality as you'd require to build a space elevator you could cram as much or more energy into the flywheel as exists in an equivalent mass of gasoline; about 40 MJ/kg. The speed at the surface of the flywheel would be about mach ~25.

It seems like much ado over nothing.
The same kenetic energy can be trapped by pumping water up a hill.

@Kennard
I very much agree with you. This is very old tech... There are various forms of energy one could choose from. Using kinetic energy seems a bit silly.

Retroworm: 200 x 25 kWh = 5000 kWh or 5 mWh. That's 20 MW for 15 minutes. Under the new tariff for limited energy storage resources, the NY grid operator (NYISO) will requires a maximum of 5 minutes of response time from the flywheel plant. 15 minutes is more than enough for any frequency regulation requirement. Apart from zero emissions and no fuel consumed (i.e. true cleantech), the real benefit is fast response to ISO control signals (<4 secs), which is an ideal complement to the slow-responding fossil generators that do regulation. The link to renewables is NOT diurnal storage as some suggest, but the ability to constantly "recycle" electricity to maintain stable grid frequency -- even with a higher percentage of generation intermittency from wind and solar.

Kennard and Smoothies: Most grid operators would agree that pumped hydro is an efficient (65-70%) and effective way to regulate frequency. And it can store hundreds of MW for hours or days, which flywheels cannot do economically. The issues are a) the cost to build one, b) the time it takes (7-10 years), c) the need for suitable geologic conditions (i.e. a mountain that can hold a lake). Have you seen any pumped hydro facilities being built lately? A 20 MW flywheel plant can provide better round-trip efficiency (>85%) and can be built without special permits or licenses in 12-18 months.

I found an interesting article the other day on these. If you don't understand the science behind flywheel as energy storage devices the you should check out this article.

http://www.damninteresting.com/the-mechanical-battery

Also I think that these are a good idea, and if we can continue to capitalize on this battery tech then flywheels could help us in other aspects of industry.

The real big value of flywheels is durability projected to be nearly 40 years with efficiency in the ninety percent bracket. The magnetic bearings will last a long time and produce no heat loss. The longevity should make them viable in a vehicle if made with nanotube flywheels with a factor of ten increases of energy density, and rotational speed. In a car it would cost less then Fifty dollars to drive from Disney Land to Disney World at speeds capable 200 miles per hour and more fun then either park.

Flywheelguy: Yes, you are right. That was some weird brain fart. My comment was only for the large scale solar/wind storage, which was mentioned in the article. For added grid stability this obviously could be very useful.

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In this Article the author mentions: "Solar and wind power in particular would be more promising if there was a way to capture and store their energy for later use."

--- Excuse me please if I am commenting out of line. But did not Nikola Tesla state that he was able to charge the Ionosphere and pull the charges back down using an antenna array? If i am not mistaking, he used pulses to charge the Ionosphere. Why can we not do this?

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