Underground Flywheels for Energy Storage

take a look at the google links. I cannot imagine you would here anything even if you stood on top of the housing.

the noiseiest part i would think is the driving of it.

if the flywheel is underground if it fell apart it would almost certainly stay under ground.

http://www.google.co.uk/search?q=Underground+Flywheels+for+Energy+Storage&sourceid=ie7&rls=com.microsoft:en-gb:IE-SearchBox&ie=&oe=&redir_esc=&ei=mu7ZS9anIoH60wT_mtRN

I wish the article had described how the flywheel (varying rpm) is coupled to the electrical source/sink (constant frequency).

This article from the area's local paper explains it a little better but I'm not sure that it answers your specific question.

With a total amount of stored energy at 20 megawatts (100 kilowatts per flywheel), I'm certain that there must be some safety hazards that have to be mitigated. But predicting safe failure modes for this type of a mechanical storage device seems more like an exercise of scaling up known safety concerns to these new dimensions rather than exploring new territory.

But this will certainly attract the antsy NIMBY Luddites. I realize that you cannot convince anyone who won't listen, but I don't understand why they think that the local community won't benefit from this.

This is as I heard it back when it was still a proposal (a year or so ago):

Supposedly, the energy is going to be hooked onto a grid that does not serve the local area. The only revenue generated for the local area (according to the last talks I heard) would be from the construction workers staying in the town's "hotels" (there is one B&B), eating in its restaurants (there is a diner and a pizzeria), and using its grocery stores (a small general store and two convenience stores).

It is a good theory.

The town where this particular one is being built has a population of about 2,500 individuals or so. The only power outages they face are due to downed trees, too much snow, etc. Not so much over-usage there.

I believe this particular system is being hooked into a power line system that carries power to other parts of the state as well as a neighboring state or states. It's situated next to a transformer station for an interstate power line system. (As an aside, my grandfather used to work with these transformers' predecesors before he retired. It's a small world!)

Ah i see so it is for use else where.

cant who ever owns the land rent it out so it give the town some revenue ?

Savy,

Unless your town produces your own electric power, this system will be helping your town. It's just that it won't be solely helping your town.

I believe the town's power is supplied by a separate company than the grid the flywheels will be connected to.

When I lived there, the town's power was supplied by NYSEG. The power lines the flywheels will be connect to (as far as I know) are owned by National Grid (formerly NYMO).

A little off-topic for flywheel grid storage/stabilization. However, pump storage hydro is a good example of an alternate system that can support and stabilize grid fluctuations.

Similar to your link...

http://en.wikipedia.org/wiki/Robert_Moses_Niagara_Hydroelectric_Power_Station

helps supply and stabilize this area. The only downside I can see to pump storage hydro is that suitable (large area) locations are pretty rare.

Regarding noise concerns, the flywheel in question should not produce any significant sound during normal operation. Rotors should have magnetic bearings and be spinning in a vacuum. Noise would be an indication of impending failure, in which case repairs should be made ASAP!

The power density still seems a bit low for current flywheel technology. Even if the cost/benefit ratio is marginal, these proposed systems will help advance the technology (or shelve it if unsuccessful).

I'm hoping the project goes well.

I wonder if the axis of the flywheels is oriented parallel to the earth's axis, in order to eliminate gyroscopic forces as the earth rotates.

When a sudden large load is thrown onto the grid, it is initially absorbed by the rotational inertia of all the interconnected generators and turbines, thereby slowing them down momentarily until their governing devices feed more fuel or water to compensate. Conversely, if a large load is suddenly dropped off, everything speeds up.

This can be observed with a simple frequency meter, or electronically. One of the "smart appliance" strategies is to incorporate such a sensor into appliances that are not too time-dependent, shutting them off to ease the total load when the grid droops a little. It doesn't usually matter if water heaters, refrigerators, and so on are shut off for short periods.

If the engineering issues for flywheels have been addressed, they are another great concept for responding to dips and surges on the grid.

Despite some questions, and some confusion between power (megawatts) and energy (megawatt-hours), this is an interesting article. Thanks for sharing it.

Is this the project?

Spin Cycles Clean Up

A U.S. Department of Energy loan guarantee of $43 million will support construction of a 20 MW flywheel energy storage plant in Stephentown, NY, by Beacon Power. The project is said to be the first full-scale commercial deployment of Beacon's technology, which will provide frequency regulation services and mark progress toward smart grid realization.

One resource this country will never exhaust is its NIMBY supply. I see an abundance of it on the Massachusetts coast while the coastline of my former home prepares to be smothered with the preferred fuel. _{(why oh why can't they get that BOP going?!)}

Everyone professes to laud 'green' technology and to want to do their share, and everyone bemoans the sluggish pace of western economies. Yet when possible solutions to economic and social problems are offered, a loud proportion morphs into Luddites, fearing that the giant flywheel will offend the large turtle on whose back our earth is so gently carried.

harrumph.

This seems to be a good application of flywheel technology. Not so much for storage of energy as stabilization of the grid. It uses energy that would otherwise be turned into heat and wasted and puts it back into the grid when needed.

I don't see a down side.

Again somewhat off topic, but in the same genre is grid attached battery storage using Vanadium Redox batteries. They have poor power density so using them for mobile applications is out, but they can be scaled up very cheaply to supply tens of megawatts worth of power. A 12 MW unit is currently being installed in Ireland, it will be the largest installation to date..

hi all, no-one has mentioned how much energy is lost by spinning and extracting energy from flywheels. The benefits are described by other members.

In general, about 40% of the energy put in is lost when you take it out again. It is converted to heat, which, of course, can be used to heat homes etc.

Nothing is free....

Regards, moe

You're right that no energy transfer/storage system is 100% efficient. But to also state the obvious, not storing this energy will guarantee a 100% loss of energy.

"40% of the energy put in is lost when you take it out again"....can you elaborate on this coz it is interesting?