Massive spinning flywheels may improve energy efficiency

[kristopher]

New spin on power | Massive spinning flywheels may improve energy efficiency

By Jay Lindsay

The Associated Press

Appeared in print: Saturday, Sep 19, 2009
Business: Home: Story

TYNGSBOROUGH, Mass. — Spinning flywheels have been used for centuries for jobs from making pottery to running steam engines. Now the ancient tool has been given a new job by a Massachusetts company: smooth out the electricity flow, and do it fast and clean.

Beacon Power’s flywheels — each weighing 1 ton, levitating in a sealed chamber and spinning up to 16,000 times per minute — will make the electric grid more efficient and green, the company says. It’s being given a chance to prove it: the U.S. Department of Energy has granted Beacon a $43 million conditional loan guarantee to construct a 20-megawatt flywheel plant in upstate New York.

“We are very excited about this technology and this company,” said Matt Rogers, a senior adviser to the Energy secretary.

Beacon’s flywheel plant will act as a short-term energy storage system for New York’s electrical distribution system, sucking excess energy off the grid when supply is high, storing it in the flywheels’ spinning cores, then returning it when demand surges. The buffer protects against swings in electrical power frequency, which, in the worst cases, cause blackouts.

Such frequency regulation makes up just 1 percent of the total U.S. electricity market, but that’s equal to more than $1 billion annually in revenues. The job is done now mainly by fossil-fuel-powered generators that Rogers said are one-tenth the speed of flywheels and create double the carbon emissions.

Beacon said the carbon emissions saved over the 20-year life of a single 20-megawatt flywheel plant are equal to the carbon reduction achieved by planting 660,000 trees...

http://www.registerguard.com/csp/cms/sites/web/business/20370762-41/story.csp

[Statistical]

1. Our data center uses flywheel power storage.

More capacity than battery but they are tiny compared to this. They are sunk into concrete to reduce damage if/when they break. I can't imagine what kind of shielding is needed to contain a 1 ton flywheel rotating at 16,000 rpm if/when it cracks and breaks apart.

[pscot]

2. Film at eleven

Actually this seems like a very good idea, considering the amount of intermittent power that's going to be created by wind and solar. It would be interesting to see some illustrations showing what the thing would look like and how it would work.

[TheMadMonk]

6. I believe the flywheels are made of composite materials.

When one fails catastrophically it turns into a fuzzball, disipaiting a lot of the stored energy in unravelling itself.

[HughMoran]

3. Good idea

Nice way to absorb the ups & downs of power generation.

[kristopher]

4. Note the cost...

Although it is actually a $69.3MM project the article only mentions the $43MM in govt loan guarantees.

20Mw of storage - but note also that there is no discussion of actual storage capacity.

That means it is not possible to evaluate the actual cost effectiveness of this project from this article - which is actually culled from a NYPSC press release: http://readme.readmedia.com/news/show/PSC-Begins-Review-of-High-Tech-Energy-Storage-Plant/953387

While this is perhaps a cost effective technology at this point and time, it isn't a technology with a future. This is because the same benefit can be had without the ratepayers picking up the tab on the very large capital investment required.

The improvements in energy efficiency associated with the electric vehicle are enough to justify the transition to electric vehicles without added value, but in fact there is a great deal of additional value provided by a huge fleet of battery electric autos - and that is its ability to serve as a storage reservoir for grid electricity. In the OP article what is being provided are "regulation services". It's been a while since I read this but IIRC we can meet our entire requirement for regulation services with less than 3% of our personal transportation vehicle fleet participating in V2G programs.

This is an audio presentation from 2007 by the originator of the V2G concept:
http://readme.readmedia.com/news/show/PSC-Begins-Review-of-High-Tech-Energy-Storage-Plant/953387

And this is a recent study that presents a more concrete example of the way the money works.

http://green.autoblog.com/tag/v2g/
USPS study shows V2G could speed internal investment return

We haven't heard anything about the 250 electric Chrysler Town and Country mini-vans joining the United States Postal Service (USPS) fleet since the Earth Day announcement but that doesn't mean sleet, snow or gloom of night has kept the mail peoples from considering the benefits that electric vehicles (EVs) may offer in the 21st century. Though the history of EVs delivering our mail stretches back to the beginning of the last century (check out this historical overview) and as recently as 2003, when a small fleet of electric Ford Rangers ...

I just posted several articles on battery technology, and all of them relate to present a picture of the EV market, size of resource and and some of the technical challenges.
http://www.reuters.com/article/earth2Tech/idUS104400379820090918
http://www.prlog.org/10346891-orchid-technologies-designs-solar-power-system.html
http://www.reliableplant.com/article.aspx?articleid=20093&pagetitle=JCI+shows+off+advanced+battery+technology+for+electric+driving

With even low penetration of EVs vehicle to grid technology is a complete game changer is the area of energy storage for both the current grid (as described in the OP) and even more importantly, for the completely renewable grid we need to build.

[TheMadMonk]

7. No the residents get to pick up the tab in another way.

You're looking at on the order of $1000 dollars worth of electronics for the two way connection to the grid, plus any required certification.

Your plan requires that vehicle owners drive with a less than full charge in their batteries.

Your plan cycles batteries in vehicles, adversely affecting their lifespan.

The required duty cycles are out of synch too. The vehicles would be disconnected from the grid during the day when solar systems would be generating and needing the storage capacity, and when connected for charging at night, the generating capacity to charge the batteries would not be there. Making the grid connection to all those vehicles during the day would be a logistical nightmare. Who would pick up that cost by the way?

[pscot]

9. There are significant revenue consequences also

States derive about $40 billion a year from gas taxes.

[kristopher]

11. That is an inevitable part of EVs.

It isn't related to V2G. The transition is going to occur, and in fact that is why the first of the three links is included; it demonstrates the inertia of the energy issues involved by stating a forecast to the effect that within a decade the $200 billion annual Chinese auto market will be dominated by electric vehicles.

This train has already left the station.

[kristopher]

10. EVs justify themselves without V2G

If you take the time to examine the information related to EVs you'll find that it is where we are going - period. That direction is based strictly on energy efficiency considerations flowing from the fact that internal combustion engines waste as heat approximately 85% of every gallon of fuel that you put into the tank. Only 15 cents out of every dollar's worth of fuel actually pushes your auto down the road. In an electric vehicle, that number is above 90%.

V2G isn't my plan, it is an accepted and desirable means of integrating the coming EV fleet with the electric grid. If you don't want to "drive with less than a full charge" in your batteries, you won't be required to participate, but there will be financial benefits for those who do. Since the statistics on driving habits very clearly show that the vast majority of drivers would not be negatively impacted by participating, then it is expected that more than enough people will WANT to do it. In other words, your intuitive sense on this point is not supported by the data. BTW, do you ever drive around with less than a full tank of gas? If you wonder about the relevance then you may not understand the way a PHEV series hybrid actually functions.

Cycling batteries is a consideration but much less than you might think - you are living in the past, not the future. The batteries being developed specifically for autos have characteristics that increasingly make this a moot point. Even with Nimh batteries (outdated) the cost analysis justifies participation at low rates of penetration. Going forward with lithium based batteries the picture is much better in the areas of power density, shelf life and cycling. So again, the technical data available says your objection in this area is unfounded.

As for building a charging network, that goes back to the FACT that battery electric vehicles are the future of transportation. Barring the emergence of some totally unknown technology, we are going to need charging stations everywhere. As to who will pay for it, the same people who paid to build our electric grid. The build up is already in the process of being planned and executed. So V2G is just iding on the cake; it piggybacks on investments that are already planned and economically justified.

The timing argument you raise is based on poor understanding of the way the current grid works and how the future grid will work. It would take a bit more time than I'm willing to devote to explaining but there are a number of papers written by a lot of people in the renewable energy field and the electric utility field that say you are not correct. Google the issue and I suspect you can find a fuller explanation in reasonably short order.

[Statistical]

45. The problem I see is V2G "uses up" an already limited range.

Take Nissan Leaf for example it has about 80 mile roundtrip range.

So I charge at night (off peak) drive to work now peak consumption time is early afternoon. If I "sell back" power to the grid that is more I need for the commute home.

There isn't much slack in EV for most consumers. Average round trip commute is 60 miles. Average EV range is 80 miles. Very little power can be "sold back".

Now if we see a substantial improvement in battery tech and EV start having a range of 100, 150, 200 miles then it makes more sense.

[kristopher]

49. It is practical and cost effective even with a 40 mile range.

The determining factor isn't what you personally drive, it is the usage by average drivers. That applies to the view of utilities and auto consumers who would choose to sell extra power and it applies to regulation power requirements.

As batteries improve and market penetration for EVs increases, the amount of reserve power increases and the role of V2G expands.

[bhikkhu]

13. I think the flywheel vs v2g argument could be simplified

If both are designed to stored and distribute energy in a grid, then distribution losses are about equal either way. What's left is the efficiency of the storage itself. I don't recall the exact numbers on conventional batteries, but they have always been pretty inefficient - losing over 10% just in heat generated during the charging process, and then spontaneously losing another 20% or so a month by internal chemical processes. In short, its like storing water in a sieve. Probably newer generation batteries are much improved but I'd be a little skeptical as to how much improvement is possible without a complete changeover to new technology.

A flywheel will have friction to contend with, but I'd think that friction losses could be more easily minimized.

[kristopher]

14. It could be simplified to that *in the way you have* if you want a false conclusion...

While there is no arguing with the fact that flywheels have advantages (for example they generally last a very long time) I don't think the efficiency argument you make would stand close scrutiny - I'm fairly confident that the energy efficiency numbers favor lithium batteries pretty strongly. But, since there is little information yet on the specifics of the batteries that are going to be in the first generation of series PHEVs it isn't possible for us, at this level, to make a legitimate detailed comparison. Especially since there are so very many specific lithium battery chemistries being fielded - each with its own set of performance characteristics.

The key element in the tradeoff between V2G and other grid energy storage options still remains the economic argument. When all the considerations are looked at batteries are the best storage option for vehicles. The evidence for that is obvious, all of the makers are bringing battery electric vehicles to market and none are bringing flywheel or fuel cell vehicles to market. That represents detailed analysis by a very wide array of groups where all are coming to the same conclusion.

Once that market is settled, then the idea of piggybacking on the capital outlay already being made for transportation is an absolute no brainer. If someone can't see something as obvious as the manner that avoiding duplicating capital costs for storage makes V2G an inevitable outcome of electric drive vehicles, I don't know what to tell you.

Don't get me wrong - if there is some sort of major advance in materials for flywheels or if there is some other development like the unveiling of a super capacitor by EEstor that performs as they have been promising for years, then I completely support the adoption of the best performing technology. However all the capital investment is flowing into batteries for a reason - batteries are the best bet.


This is what is right on the horizon, they are working out the manufacturing methods right now. The estimated range and longevity of this chemistry is nothing short of astounding - 800 miles stored in battery weight that now delivers 100 miles.

Stanford Report, December 18, 2007
Nanowire battery can hold 10 times the charge of existing lithium-ion battery

BY DAN STOBER

Stanford researchers have found a way to use silicon nanowires to reinvent the rechargeable lithium-ion batteries that power laptops, iPods, video cameras, cell phones, and countless other devices.

The new technology, developed through research led by Yi Cui, assistant professor of materials science and engineering, produces 10 times the amount of electricity of existing lithium-ion, known as Li-ion, batteries. A laptop that now runs on battery for two hours could operate for 20 hours, a boon to ocean-hopping business travelers. "It's not a small improvement," Cui said. "It's a revolutionary development."

The breakthrough is described in a paper, "High-performance lithium battery anodes using silicon nanowires," published online Dec. 16 in Nature Nanotechnology, written by Cui, his graduate chemistry student Candace Chan and five others. The greatly expanded storage capacity could make Li-ion batteries attractive to electric car manufacturers. Cui suggested that they could also be used in homes or offices to store electricity generated by rooftop solar panels.

"Given the mature infrastructure behind silicon, this new technology can be pushed to real life quickly," Cui said.

The electrical storage capacity of a Li-ion battery is limited by how much lithium can be held in the battery's anode, which is typically made of carbon. Silicon has a much higher capacity than carbon, but also has a drawback.

Silicon placed in a battery swells as it absorbs positively charged lithium atoms during charging, then shrinks during use (i.e., when playing your iPod) as the lithium is drawn out of the silicon. This expand/shrink cycle typically causes the silicon (often in the form of particles or a thin film) to pulverize, degrading the performance of the battery.

Cui's battery gets around this problem with nanotechnology. The lithium is stored in a forest of tiny silicon nanowires, each with a diameter one-thousandth the thickness of a sheet of paper. The nanowires inflate four times their normal size as they soak up lithium. But, unlike other silicon shapes, they do not fracture.

Research on silicon in batteries began three decades ago. Chan explained: "The people kind of gave up on it because the capacity wasn't high enough and the cycle life wasn't good enough. And it was just because of the shape they were using. It was just too big, and they couldn't undergo the volume changes."

Then, along came silicon nanowires. "We just kind of put them together," Chan said. For their experiments, Chan grew the nanowires on a stainless steel substrate, providing an excellent electrical connection. "It was a fantastic moment when Candace told me it was working," Cui said.

Cui said that a patent application has been filed. He is considering formation of a company or an agreement with a battery manufacturer. Manufacturing the nanowire batteries would require "one or two different steps, but the process can certainly be scaled up," he added. "It's a well understood process."

Also contributing to the paper in Nature Nanotechnology were Halin Peng and Robert A. Huggins of Materials Science and Engineering at Stanford, Gao Liu of Lawrence Berkeley National Laboratory, and Kevin McIlwrath and Xiao Feng Zhang of the electron microscope division of Hitachi High Technologies in Pleasanton, Calif.

[bhikkhu]

15. So batteries store energy more efficiently than flywheels

If I understand the reply?

I was thinking based on the OP that the type of flywheel being discussed was a large installation, designed to store grid energy. Putting a flywheel in a car has an inherent problem in that it has to be heavy to function, while a vehicle must be light to perform well.

[kristopher]

16. Yes, I think so.

I haven't checked it lately but I did a detailed study of the various options for storage. Flywheels are under 90% and lithium is better than 90% - and while the amount in each direction reflects the specific design of the system the worst lithium basically picks up where the best flywheel leaves off.

In and of itself that isn't the determining factor. If we were taking the best off-the-shelf technologies available now and using them for fixed location storage, I'm sure there would be a real competition between the two (however all direct costs considered natural gas would probably come in at about 1/4 of the best either could offer).

But given that the battery technologies have captured the auto market, then the cost figures turn heavily in the favor of batteries.

[joshcryer]

19. It depends upon your perspective. Lithium has a higher energy density, but shorter lifetime.

The latest lithium batteries manage about 10,000 cycles. They last one to two years. But as time goes on their charge decreases. Flywheels can last hundreds of thousands if not millions of cycles and last many years without any capacity losses over time.

If flywheels are accepted as a potential battery technology for vehicles, they may be able to compete significantly with lithium. However, it may not be in the interests of manufacturers to produce batteries that don't need replacing every two years which degrade over time.

[bhikkhu]

21. I don't see flywheels as a replacement for car batteries

They just don't work that way. You could get some advantages by using a flywheel as an energy storage device in a vehicle, but you still need a battery anyway. Adding a flywheel to existing engine technology is an additional level of complexity, weight and expense, for a relatively small benefit.

As a large scale power storage device - that's a whole different story. If you look into the whole reason for the V2G push, its that there is essentially zero storage capacity built into the current electric grid. If batteries were better than they are and if the grid were rebuilt to allow them to provide remote storage for excess capacity it would make a number of things easier to manage, and ease some predicted future supply crunches that otherwise require new power plants. On the other hand, as in the OP, a flywheel could store energy as well and make the V2G idea redundant or unnecessary.

[joshcryer]

23. Thought we were talking about EVs (electric vehicles).

Lithium has an energy density only somewhat better than flywheels, it's not like it's an order of magnitude or anything (one or two points higher, as opposed to say, ethanol, which is more than 25 times more energy dense than either technology).

Invest in carbon composite flywheels and we may in fact be on to something.

My problem is with producing technologies that require constant recycling, constant chemical manufacture. Lithium-ion can be clean, but why worry about keeping it clean when there are clear alternatives that should at least be explored?

Flywheels:
90% efficiency has been achieved (contrary to claims here).
Extremely quick charging times (15 minutes).
Based on mostly inert materials.
Similar energy density to lithium (could be higher with composites).
Much longer lifetime.
No memory effect or discharge over time.
Small recycling program, flywheels that meet a certain guideline would just be refurbished.


Lithium:
90 minute charge times (so far).
Slightly higher energy density than flywheels.
Short lifetime (compared to flywheels).
Memory effect, half duty cycle will have a battery 80% efficient.
Very large recycling program, batteries would need to be replaced every two years. Non-trivial costs. Peak lithium could become a problem.

I don't really have any problems with V2G, though I think renewable farms everywhere could use a few large flywheel storage facilities buried somewhere on them, handling load balancing at the source of energy, this arguably uncomplicates the grid. With V2G you will need significant wiring up of society, which may or may not be possible for quite some time.

[kristopher]

25. Where is the economic part of the discussion.

Why would you ignore the decisive factor?

Oh, that's right - you don't know how to make an honest argument.

[bhikkhu]

27. They're both pretty expensive

and to be beneficial require the replacement of a great deal of infrastructure. I have about the same perspectives - flywheels are simple mechanical devices, where batteries are generally toxic chemical soups. But they do different things, and both are likely necessary.

If you just want to talk about what's economical we can talk about my bicycle, and my clothesline, and how to hand-wash clothes and dishes and things (:

[kristopher]

29. You're making another totally muddled argument

Answers pointing out Josh's fabrications:
Flywheels are not appropriate for EVs. Period. The only way you get there is to posit a non-existent flywheel that magically has a power to weight ratio that can work in an auto; none exists and there is no promise of one anywhere on the horizon. See post 26 by Statistical.

Lithium batteries are not "a toxic mix of chemicals" and they recycle easily and economically. You are either totally ignorant regarding battery chemistry or you are deliberately saying something false. *

The "economic argument" is related to relative costs of deploying the two technologies and has nothing to do with lifestyle choices.

Even though it has been laid out several times here it is again:
Batteries are the choice for PHEVs and EVs.
Using V2G an electric vehicle fleet can serve the same function as the large stationary flywheels without the additional capital investment needed to deploy flywheels.
Flywheels are a poor choice.



The remarks about landfill disposal do not apply to an environment where the demand for lithium excalates to include batteries for an EV fleet. For several reasons those batteries are going to be recycled.

Spent Consumer Lithium Batteries and the Environment
March 2001

EXECUTIVE SUMMARY. Spent consumer lithium batteries are not hazardous wastes because they are neither toxic nor reactive. Consumers routinely dispose of these batteries commingled with other garbage in the municipal solid waste stream. Spent consumer lithium batteries disposed in this manner do not pose environmental or safety hazards. Therefore, there is no need to require the collection and recycling of spent consumer lithium batteries for the purposes of environmental protection.

BACKGROUND. Lithium metal is used as a negative electrode material in undischarged lithium batteries. Most lithium batteries fall into two categories: lithium manganese dioxide or lithium poly-carbon monofluoride. Lithium batteries are light in weight and compact and possess high energy density, excellent shelf life, long-term reliability, and high rate capability over a broad temperature range.

Spent lithium batteries are not reactive. Lithium metal is a reactive material. As a lithium battery is discharged, however, the metallic lithium is converted into a non-reactive lithium compound. One of the features of the lithium battery is its constant voltage (flat discharge curve) until virtually all of the lithium has been converted into a lithium compound. There is, therefore, no reason why a user would replace and discard the battery until the voltage drops sharply. At that time, virtually all of the lithium is no longer present in the reactive metallic state.

By design, manufacturers construct the lithium batteries with an excess positive electrode material to assure that there will be enough of the positive material to react with all of the metallic lithium. This is a safety feature manufacturers design into the battery.

Spent consumer lithium batteries are routinely disposed with other garbage in the municipal solid waste stream. Batteries disposed in this manner generate little heat and pose no safety concerns during disposal.

Spent lithium batteries are not toxic. The U.S. EPA uses the Toxicity Characteristics Leaching Procedure (TCLP) to determine whether a waste is hazardous. Lithium batteries pass the U.S. EPA's TCLP test and therefore are not considered to contain toxic materials that would be hazardous for disposal. EPA maintains a list of metals it considers hazardous. Lithium is not included on this list. In addition, there is no lithium metal present in a spent battery. US law, therefore, does not restrict the disposal of consumer lithium batteries in the solid waste stream. In addition, the overall volume of spent lithium batteries in landfills is negligible. Lithium batteries are, therefore, safe for disposal in the municipal solid waste stream.
http://www.nema.org/gov/env_conscious_design/drybat/upload/SpentConsumer_Lithium_Batteries_and_the_Environment.doc.

Still waiting for you to support the (false) statement that lithium batteries for cars are going to require replacement every two years.

[joshcryer]

35. You're correct, it's closer to 8 years.

Sorry.

[bhikkhu]

52. not knowing something=totally ignorant...

nice. I did not know that Lithium batteries were considered non-toxic. Having been around lead/acid batteries for ages and hearing regularly of new ones using various heavy metals, I just assumed. I'll look forward to seeing those in vehicles, as they will be a great improvement.

Of course flywheels have limited to no use in most vehicles. I do think they sound like a good alternative for large scale energy storage though, as the Op details. If you look at how a solar plant would work, it needs to be built with a means for energy storage if its to be anywhere close to useful as a primary energy source. Personally, I think flywheel technology and V2G systems would work together very well in a hypothetical future grid.

[kristopher]

57. I would like to agree just to be reasonable,

but somewhere along the way I've seen the numbers on what the estimated total capacity of V2G will be at various levels of market penetration and for various basic battery pack capacities. Those numbers were pretty convincing evidence that appropriate applications for stand alone storage in this capacity range are going to be fairly limited. There will be a much larger role for higher capacity systems like pumped hyro, CAES and systems that can be scaled up to that range easily. See the link for some generic information on total market, a pumped hydro system, and a thermal heat storage system that might work out to fill that niche.

http://isentropic.co.uk/index.php?page=storage

[bhikkhu]

59. So the whole thing is a bait and switch?

Post a good article about promising flywheel technology as a means of storing energy, then answer all positive replies in the negative - flywheels are no good - the future is all about V2G and pumped hydro?

on edit - re-reading the whole thread, that does seem to be it. Rather trollish, don't you think? Call a bunch of people stupid while you're at it, who read the article you posted and think it sounds like a good idea. Geez - are you trying to impress anyone, or just blowing off steam? Something about this forum seems to draw out the worst in people...

[kristopher]

61. If that's the way you see it...

I posted 3 other articles at the same time on different aspects of electric vehicles - all without comment.

I routinely post on different technologies, and I routinely respond to posts demonstrating false understanding of the issue. I don't think you are accurate in stating that I "call(ed) a bunch of people stupid... who read the article you posted and think it sounds like a good idea".

What I experienced was a couple of people who want to deny some obvious, factual information for no reason other than it doesn't fit their desires.

I really didn't understand your remarks here, but on reviewing the thread I see that I made a mistake and wrote a response to post #23 but posted that response to post #27 - your post. I thought it was odd that you responded as you did, but didn't pick up the reason until now. Please note I even included the name of poster of #23 in the text.

I apologize for the error.

[joshcryer]

32. I said manufacturers may not find it beneficial to make a battery that lasts many years.

Which is the *only* fucking reason flywheels wouldn't be adopted. They're cheaper in every way. They're more effective in every way.

[kristopher]

34. No you didn't. That is yet *another* false claim

Quote your post#19 this thread:
It depends upon your perspective. Lithium has a higher energy density, but shorter lifetime.

The latest lithium batteries manage about 10,000 cycles. They last one to two years. But as time goes on their charge decreases. Flywheels can last hundreds of thousands if not millions of cycles and last many years without any capacity losses over time.

If flywheels are accepted as a potential battery technology for vehicles, they may be able to compete significantly with lithium. However, it may not be in the interests of manufacturers to produce batteries that don't need replacing every two years which degrade over time.

You also said it explicitly in other posts. Were you deliberately presenting false information or do you have support for that assertion?


BTW do you realize how incoherent your logic in post 19 & 32 is?

Maybe you should lay off the bud.

[joshcryer]

36. Yeah, you're right, in cars they last 8 years or more.

[TheMadMonk]

44. Actually many economic factors are covered imlicitly in that post.

The single biggest one would be fittinga large number of (semi)public parking spaces with hardened (energy thief/vandal/weather/collision) connection points.

Next is whole life cycle costs of the storage media. Including envrionmental costs of manufacture and disposal/recycling. All of amortized over the useful lifespan.

No specific figures were quoted, but so bloody what, such is an exercise for you or I if we're really interested. But they're not really necessary. A simple comparisons of the listed pros and cons makes the choice obvious for a fixed installation with an anticipated lifetime of decades. Flywheels win hands down.

Batteries work very nicely for motor vehicles, I don't believe they're an option for transient storage. One major disadvantage of having a large flywheel in a motor vehicle is that the stubborn things do not take kindly to being made to go around corners. In fact one major reason, that has nothing to do with containment of flying shrapnel, why flywheels are burried, is it makes it easier to stop them from wandering in circles as the Earth rotates underneath them.

[kristopher]

48. That totally misses the relevant points

The money is ALREADY GOING TO BE SPENT FOR THE ELECTRIC VEHICLE INFRASTRUCTURE.

V2G IS A BENEFIT WE GET FOR VERY LITTLE TO NO ADDITIONAL COST.

Did you hear it that time?

[TheMadMonk]

58. Bull. Considerable additional cost. A V2G charging station will cost...

...considerably more than an ordinary charging station. Going off the price for a back to grid solar instalation I'd guestimate the additional electronics would make one on the order of 1000 dollars more expensive.

Thats for a home station. A cmercial public/semi-public one also needs to manage billing or crediting of the right vehicle owner; be hardened against vandalism, the weather (if outdoors), touch parking by little old ladies and theft of electricity. That's another couple of grand at least. And this cost has to be repeated for every single parking space that is to be connected.


The infrastructure to use electric vehicles connected to the grid for storage and load balancing would be roughly comparable in cost to a similar capacity flywheel based system, and furthermore the maintenance costs of a public/semi-public V2G system would be enormously higher.


TANSTAAFL. There ain't no such thing as a free lunch.

[kristopher]

60. Bull right back atcha there brainiac.

There are already plans to integrate the grid with digital technology capable of handling the generation distributed at the household and business level. The control systems will be part of the digital system of the car - it requires only the addition of programming allowing the car to not only buy electricity via direct communication with the utilities (which is also the answer to the theft problem you worry about), but to also sell electricity back to the utility. The rest of your post is likewise a product of failure to understand what you are busy trying to criticize.

Give it up, my friend. You simply are not correct.

Let me offer a sincere suggestion. When you don't know WTF you are talking about, try asking questions instead of acting like a meathead. The points you raise are mostly valid questions, but they've been looked at and the conclusions support V2G. While pithy old saws might seem an appropriate way to judge the relative merits of two technologies involved in a complex system, it really doesn't do anything to actually derive a valid answer.

Apparently you've settled on the logical fallacy of assigning the cost of transitioning to EVs entirely to the ancillary benefit of V2G grid support. Well, that's ok if you want to do it that way, but be sure to calculate all the benefits that are going to flow from the cost. There will be an immediate reduction of between 40-60% in greenhouse gas emissions from the personal transport sector and that will grow as the renewable grid takes shape - a grid that has been enabled largely by V2G technology.

That means not only does credit for the immediate reduction in GHG from the transportation sector accrue to the cost of V2G, but also a good deal of the credit for ending GHG emissions from the electric power sector.

That, of course, comes with the reduction in our balance of overseas payments for petroeum - payment which is roughly EQUAL to our annual trade deficit. That, of course means that we will no longer have to borrow money from countries like China. It also means that since we don't need foreign petroleum we wont need to have an expansionist foreign policy and there will be world peace.

All that for the price of V2G.

Wow.
Try reading this:
http://docs.google.com/gview?a=v&q=cache:0tKOqX811q4J:www.ferc.gov/about/com-mem/wellinghoff/12-30-08-energy-washington.pdf+Administration+a+Greener+FErC&hl=en&gl=us

Then this:
http://www.oe.energy.gov/DocumentsandMedia/final-energy-storage_12-16-08.pdf

And then this:
http://www.ferc.gov/about/com-mem/wellinghoff/3-30-07-wellinghoff.pdf

That should give you enough information to know that the information I'm relating isn't an arbitrary opinion but is instead a summary of the best data available on the topic. Your objections are less well founded and I'd recommend that you use the Google to explore a bit. I'll be happy to help if I can.

[Statistical]

26. Largest problem is weight which is very important for mobile applications.

flywheel density is <100wh/kg. The density tends to increase with weight so smaller flywheels for use in mobile applications are likely in the 50-80wh/kg range. Many of the components don't scale down well (vacuum pumps, containment) so smaller fly wheels tend to be less efficient in terms of wh per kg.

Lithium Ion is more on the magnitude of 150 to 200wh/kg.

All things be equal a flywheel system will likely way twice as much and likely closer to 3 times.
Considering battery pack on EV run up to 500lbs that is a lot of extra weight.

[joshcryer]

40. I think there needs to be more R&D into them.

I like them because they are a potential solution with a lower environmental impact.

[kristopher]

24. Where do you get this nonsense?

Please support the false statement that state of the art lithium batteries only last 2 years (or that 10,000 cycles is only enough for two years if that was the intended bs).

The only other persona I've seen make so many basic errors is nnads.

[joshcryer]

33. Oh geez. We're talking high density long duty cycles.

Of course low density lithium batteries can last much longer. Obviously you know nothing about the state of the art in lithium batteries.

[kristopher]

37. You just make --it up as you go along, don't you?

Time Tested: New EV Battery Displays Remarkable Lifespan

When it comes to electric vehicles, critics have referred time and again to the fact that the death and replacement of batteries nullifies any savings made at the pump. With a battery’s limited lifespan, and battery prices still high, drivers may not be saving much. However, recent tests by battery provider Southern California Edison (SCE) show

Over the past two and a half years, SCE has been testing a lithium-ion battery sub-pack. And the results are incredible. The lithium-ion battery has displayed remarkable longevity, surviving 180, 000 miles with no significant deterioration. With the average family vehicle traveling less than 15,000 miles per year, this test holds great significance. This dramatic increase in the life expectancy of an EV battery pulls the cost equation more convincingly on the EV’s side.

The battery, a Johnson Control-Saft lithium-ion battery subpack, was tested in a commercial delivery van in a laboratory setting at SCE’s Electric Vehicle Testing Center in Pomona, CA. The battery subpack is one sixth of the actual battery size used in a plug-in hybrid electric vehicle.

With such remarkable test results, and testing still in progress on the subpack, the U.S. Department of Energy has asked SCE to test the battery’s viability for passenger car performance. The Department of Energy supplied a full sized battery for further testing.

SCE is testing the battery in support of the Electric Power Research Institute’s (EPRI) evaluation of plug-in hybrid EVs.

http://gas2.org/2009/06/04/time-tested-new-ev-battery-displays-remarkable-lifespan/

This is an example of where the edge of on-the-road technology is.

Lithium Titanate Batteries Offer Exceptional Fast Charging Capabilities

By Eric Loveday Eric Loveday, Author, August 30th, 2009

In order to counter the initial affects of range anxiety, several different things must be taken into consideration. From charging stations located at convenient mileage intervals, to marketing departments assuring would be buyers that there range numbers are indeed accurate, everything must be accounted for. One aspect of charging that could quickly alleviate most fears of range anxiety is fast charging capabilities. Many battery manufacturers allow the use of fast chargers on their batteries, but some do not. The reason that fast charging is not permitted on some battery design is associated with battery warranty concerns. If a battery manufacturer promises 10 years of life from their batteries, then they will provide a warranty for that time frame. Fast charging, due to the strains placed on the battery, could significantly reduce the life of the battery causing failures prior to the end of the warranty period. Current battery technology such as lithium manganese and lithium iron phosphate do not respond well to fast charging. The technology is capable of fast charging, but it reduces the life of the battery. The most promising technology for fast charging is lithium titanate which through testing shows little negative affects due to fast charging. Lithium titanate battery technology is expensive at this point, but prices will drop over time. A fast charge setup allows some batteries to be charged to 80% capacity in less than 30 minutes. This type of charging allows buyers to stop at a grocery store, pick up a few products, nearly recharge their car to capacity and head off on their way. Fast charging is essential to an EVs success in our fast paced country where time is money and fast is never fast enough.

In order to counter the initial affects of range anxiety, several different things must be taken into consideration. From charging stations located at convenient mileage intervals, to marketing departments assuring would be buyers that there range numbers are indeed accurate, everything must be accounted for.

One aspect of charging that could quickly alleviate most fears of range anxiety is fast charging capabilities. Many battery manufacturers allow the use of fast chargers on their batteries, but some do not. The reason that fast charging is not permitted on some battery design is associated with battery warranty concerns.

If a battery manufacturer promises 10 years of life from their batteries, then they will provide a warranty for that time frame. Fast charging, due to the strains placed on the battery, could significantly reduce the life of the battery causing failures prior to the end of the warranty period.

Current battery technology such as lithium manganese and lithium iron phosphate do not respond well to fast charging. The technology is capable of fast charging, but it reduces the life of the battery. The most promising technology for fast charging is lithium titanate which through testing shows little negative affects due to fast charging.

Lithium titanate battery technology is expensive at this point, but prices will drop over time. A fast charge setup allows some batteries to be charged to 80% capacity in less than 30 minutes. This type of charging allows buyers to stop at a grocery store, pick up a few products, nearly recharge their car to capacity and head off on their way.

Fast charging is essential to an EVs success in our fast paced country where time is money and fast is never fast enough.

[joshcryer]

39. Nah, just misinformed.

I'll never forget getting a new laptop 5 years ago and its lithium ion battery died within 3 months. They wouldn't cover it.

[Statistical]

46. Yes on all accounts.

The round trip efficiency (electricity -> kinetic energy -> electricity) of flywheels is about 85% per Beacon Power (one largest "storage flywheel makers".

The round trip efficiency of lithium-ion batteries is already at 90%.

The parasitic loss (self discharge) for lithium ion battery is about 10% to 20% per month but it is even more for flywheels. Also parasitic loss isn't as important as round trip efficiency.

Really the only advantage flywheels offer is cost per kwh in capacity.

[bhikkhu]

51. Either would be nice to see

The one remotely comparable means for energy storage I can think of is done a few places - where excess electrical capacity pumps water up into holding tanks or lakes, then when capacity is needed it runs the other way, driving generators. I never looked at the efficiency, but its certainly much less that 85%..

[TheMadMonk]

42. I will applaud and whistle when these battery technologies move to market.

Same as I will when photovoltaics actually do "sell for a fraction of what they do now." as has been predicted for twenty odd years now. Instead each year it is yet another tiny incremental improvement in price per watt.

I pretty avidly read up on new developments in a wide range of fields, and the unfortunate truth is that a whole lot of "revolutionary developments" never make it off the starting blocks for one reason or another, or remain forever in development, ironing out bugs that manifest in a mass production environment. Funding dries up and moves onto the next big thing.

[BREMPRO]

5. cool! sounds like a great way to efficiently manage grid power demand

[HysteryDiagnosis]

8. Flywheels will be used in cars soon... even though one may say

they have been used for decades, this use will mirror the purpose of what you have posted.

http://www.autolinedetroit.tv/journal/?p=545


Now the idea is being revived and a flywheel-hybrid, or what’s called a flybrid, will appear on several Formula One cars next year. The organizers for the Le Mans 24 hour race, and the American Le Mans Series are interested in allowing them in 2010.

As automakers around the world race to come up with advanced batteries for hybrid systems, it’s fascinating to see that the flywheel could turn out to be a competitive energy storage device.

[kristopher]

12. That is actually pretty different in the type of energy being stored

Simple steel flywheels are employed in reciprocating
engines to smooth out power pulses from the pistons.

Flywheels store electricity by converting it to kinetic
energy: electricity to be stored powers an electric motor
which increases the speed of the flywheel, while electricity
is recovered by running the motor as a generator which
causes the flywheel to slow down. The amount of energy
stored is proportional to the mass of the flywheel and to the
square of its angular velocity. Thus, the rotational speed is
much more important than the mass in determining the
amount of energy stored. The maximum energy which can
be stored is dependent upon the tensile strength of the
material from which the flywheel is constructed. The cir-
cumferential tensile stress in the rim is also proportional to
the square of the angular velocity. It follows that the
maximum stored energy is to be found in a flywheel of
high tensile strength rotating at the maximum safe speed.
The highest tensile flywheels are not made of steel, but of
fiber-reinforced composites such as carbon-fiber/epoxy or
Kevlar/epoxy. As well as rotating faster and storing more
energy than steel flywheels, these composite wheels are
much safer if the maximum safe speed is exceeded, since
they tend to delaminate and disintegrate gradually from the
outer circumference, to produce fine fibers, rather than
explode catastrophically.

This is from a 2001 paper on energy storage (so it is outdated regarding battery chemistries).
Energy storage — a key technology for global energy sustainability
R.M. Della, D.A.J. Randb,*
Journal of Power Sources 100 (2001) 2–17

[Terry in Austin]

17. Flywheel storage: interesting technology that's worth revisiting

"Super Flywheel to Power Zero-Emission Car"
- Popular Science Magazine, August 1970

As composites improve that can better handle the necessary high rpm's, flywheel technology becomes more attractive.

Large scale stationary applications like those mentioned in the OP seem like a natural.

[kristopher]

18. Except that small scale distributed storage can do the same thing cheaper.

[NecklyTyler]

53. It would seem the gyroscopic effect of the rotating mass would interfere with the car's handling

[HysteryDiagnosis]

54. This one looks to be a small diameter unit which would limit the

gyros... I think the Formula 1 people have a pretty good handle on things and they see it as a way to store energy most likely to enhance getting back up to speed after some hairpins or switchbacks.

[Statistical]

56. The ones in Formula 1 cars are used as a "boost"

thus they contain relatively small amount of power. Even a 1kwh device would have sufficient power to boost the vehicle engine output by 240w (320hp) for 15 seconds.
So as a boost it the gyroscopic effects are minimal.

However to completely replace the battery pack on a EV would require a flywheel with 10x to 30x as much power and thus 10x to 30x as much gyroscopic forces.

It would be useful for traditional (non plug in parallel hybrids) like the Prius.

The Prius battery pack is only about 1.3kwh due to inefficiencies of converting kinetic energy to electrical energy and back to kinetic a 1.3kwh battery pack could likely be replaced with a 1.0 kwh flywheel which requires much less complicated electronics and charge controllers. Plus building a flywheel that lasts 20 years is a pretty easy challenge. Since the Prius uses "heavy" NiMh batteries the flywheel would provide similar watts / kg.

[muriel_volestrangler]

63. Formula One cars aren't using flywheels yet, just batteries

One is still under development:

Although the Formula One Teams Association (FOTA) has agreed to run without the Kinetic Energy Recovery System (KERS) in 2010, the Williams team has revealed that development work continues on its unique flywheel system as it hopes to debut the device next year.

Having been suspended - along with Force India - from FOTA meetings earlier in the 2009 season, the two teams were reinstated before the Italian Grand Prix although the Grove outfit does not intend to halt development on its KERS unit, which is the only system to use a flywheel.

As the KERS components of all other teams store their kinetic energy in batteries, Williams' system is exclusive in that a flywheel is used. Work on the part has proven to be tricky thus far, however, as technicians sought a way in which the wheel can rotate whilst the car is in motion at high speed.

http://f1.gpupdate.net/en/news/2009/09/22/williams-developing-kers-for-next-season/

[Terry in Austin]

64. Vertical shaft limits gyroscope effect on handling

At the same time, it resists tipping forces.

[excess_3]

20. now much energy is stored? .nt

[Statistical]

47. The 20MW plant consists of 200 Beacon Smart Energy 25 flywheels.

The flywheel stores 25kWh and has peak output of 100kW (15 minutes of capacity).

So storage capacity of entire plant would be 200 * 25kwh = 5mWh.

[Kablooie]

22. The problem with flywheels is the flies don't live very long and have to be replaced often.

And a really massive flywheel would be one of the most horrifying things known to man.

[Nederland]

50. Thank you

I needed a laugh...

[phantom power]

28. I might live to make my money back on these guys yet.

[kristopher]

30. Two sets of words for you.

Set 1: Sunk cost

Set 2: Dead cat bounce

[phantom power]

31. hee, here's a third set: "Tech Bubble"

The top of which was when I bought their stock.

:rofl:

[kristopher]

38. Been there done that...

Grab whatever you can from the press release...

[Fledermaus]

55. Gosh, I've been purchasing their stock, on and off, since October of last year.

I'm just breaking even. It's been hard for them to get a loan so they have been selling more stock. Water downs the value of the stock we own and keeps the stock price depressed.

[HamdenRice]

41. LEVITATING???

Does this mean they are using superconducting super magnets? How much does that cost?

I can see the advantages of reduced friction, but how much power do the magnet absorb, and how to you tap the power?

Or am I misreading the word, "levitating"?

[Statistical]

43. No need for super conductors... losts of applications of magnetic bearings.

This isn't really revolutionary or new.

A large fixed magnet provides most of the "lift" it is coupled with a smaller electromagnet which can fine tune the amount of lift to keep the flywheel stable.

Magnetic bearings have been used for decades at room temperature in motors and turbines.

[HamdenRice]

62. Thanks -- very interesting. Magnets are amazing. nt