Use gravity to store wind power?

[SickBeast]

What if wind turbines powered an electric motor to hoist up a very heavy object and then sit it on a ledge. Once the wind dies down, that object (attached to a pully) could generate electricity using gravity.

Is this not a simpler solution than storing excess wind energy using batteries?

 

[KillerCharlie]

First of all, it's silly to go from wind->motor->gravitational potential->motor->electricity when you could just go wind->motor->electricity.

Also, do a back-of-the-envelope calculation. Say you want to power your 500W computer for 2 hours and you have something that will hoist a weight 200 ft up into the air. How much weight would you need?

1kWH = 3600000 Joules

Gravitational potential = mgh = 3600000 = mass * g * (h = 200 ft = 61 m)

3600000 = mass * 9.8 * 61

mass = 6022 kg = 13,000 lbs just to run your computer (I hope I didn't mess up a decimal place)

 

[WildHorse]

KillerCharlie,

yes you certainly killed his brainstorm

in brainstorming, as you already know, a guy can express a nonsensical idea that is still valuable because it triggers somebody else's different idea, and good things might cascade from that

 

[Gibsons]

Originally posted by: SickBeast
What if wind turbines powered an electric motor to hoist up a very heavy object and then sit it on a ledge. Once the wind dies down, that object (attached to a pully) could generate electricity using gravity.

Is this not a simpler solution than storing excess wind energy using batteries?

A flywheel might be a better way. Or maybe even electrolysis.

 

[wwswimming]

Originally posted by: SickBeast
What if wind turbines powered an electric motor to hoist up a very heavy object and then sit it on a ledge. Once the wind dies down, that object (attached to a pully) could generate electricity using gravity.

Is this not a simpler solution than storing excess wind energy using batteries?

actually that's such a good idea it's already in use ... sort of.

pumped water storage involves pumping water to a height & then re-capturing its energy when it's released.
http://en.wikipedia.org/wiki/P...orage_hydroelectricity

of course there can be problems with regulators
http://earth2tech.com/2009/05/...a-heck-of-a-long-time/

 

[silverpig]

Originally posted by: Gibsons

Originally posted by: SickBeast
What if wind turbines powered an electric motor to hoist up a very heavy object and then sit it on a ledge. Once the wind dies down, that object (attached to a pully) could generate electricity using gravity.

Is this not a simpler solution than storing excess wind energy using batteries?

A flywheel might be a better way. Or maybe even electrolysis.

Flywheels are an excellent way to store power for relatively short periods of time. In fact, I think you can get commercially available flywheels for your house to store your solar/wind power from the day.

 

[KIAman]

Originally posted by: silverpig

Originally posted by: Gibsons

Originally posted by: SickBeast
What if wind turbines powered an electric motor to hoist up a very heavy object and then sit it on a ledge. Once the wind dies down, that object (attached to a pully) could generate electricity using gravity.

Is this not a simpler solution than storing excess wind energy using batteries?

A flywheel might be a better way. Or maybe even electrolysis.

Flywheels are an excellent way to store power for relatively short periods of time. In fact, I think you can get commercially available flywheels for your house to store your solar/wind power from the day.

I agree. My work implements massive flywheels spinning at 60,000 RPM in a magnetic vacuum to give power to our data center in the event of a power loss. Every DRP (disaster recovery plan) simulation has ran flawlessly.

 

[sao123]

using this method, you would have to have an exceptionally high cliff to be able to generate power for more than a minute...
(Ie the time it would take the object to fall)

 

[PlasmaBomb]

Originally posted by: KIAman

Originally posted by: silverpig

Originally posted by: Gibsons

Originally posted by: SickBeast
What if wind turbines powered an electric motor to hoist up a very heavy object and then sit it on a ledge. Once the wind dies down, that object (attached to a pully) could generate electricity using gravity.

Is this not a simpler solution than storing excess wind energy using batteries?

A flywheel might be a better way. Or maybe even electrolysis.

Flywheels are an excellent way to store power for relatively short periods of time. In fact, I think you can get commercially available flywheels for your house to store your solar/wind power from the day.

I agree. My work implements massive flywheels spinning at 60,000 RPM in a magnetic vacuum to give power to our data center in the event of a power loss. Every DRP (disaster recovery plan) simulation has ran flawlessly.

WTH is a magnetic vacuum? I think you mean vacuum, since any air would quickly slow something running at 60k rpm.

 

[Gibsons]

Originally posted by: PlasmaBomb

Originally posted by: KIAman

Originally posted by: silverpig

Originally posted by: Gibsons

Originally posted by: SickBeast
What if wind turbines powered an electric motor to hoist up a very heavy object and then sit it on a ledge. Once the wind dies down, that object (attached to a pully) could generate electricity using gravity.

Is this not a simpler solution than storing excess wind energy using batteries?

A flywheel might be a better way. Or maybe even electrolysis.

Flywheels are an excellent way to store power for relatively short periods of time. In fact, I think you can get commercially available flywheels for your house to store your solar/wind power from the day.

I agree. My work implements massive flywheels spinning at 60,000 RPM in a magnetic vacuum to give power to our data center in the event of a power loss. Every DRP (disaster recovery plan) simulation has ran flawlessly.

WTH is a magnetic vacuum? I think you mean vacuum, since any air would quickly slow something running at 60k rpm.

and heat it up substantially... I suspect he means magnetically suspended within a vacuum (?). Hard to imagine a better way to reduce friction.

KIAman, just how massive are your flywheels? tons? At 60k, they need to be made from a very strong material, right? Biological rotors that go that fast are usually made out of titanium. "catastrophic failure" is pretty scary with these things.

 

[PowerEngineer]

Originally posted by: KillerCharlie
First of all, it's silly to go from wind->motor->gravitational potential->motor->electricity when you could just go wind->motor->electricity.

While it's certainly less efficient, I wouldn't call it silly.

One of the challenges that electric utilities must face is that their customers decide when and how much power they want to use. It's up to the utilities to dispatch generation to maintain a minute-to-minute (even second-to-second) balance against customer demand. Renewables (like wind and solar) are largely uncontrolled (i.e. the amount they generate is dependent only on current wind or solar conditions which defy current forecasting methods and can change drastically within minutes) and therefore can exacerbate the generation-load mismatches. One way to deal with the problem is to add dispatchable energy storage capacity (such as pumped storage mentioned earlier) to help soak up excess generation as stored energy to be released as electrical power again minutes or hours later when more generation is needed. The only other way to do this is to give utilities more options to control customer loads (e.g. shut off your air conditioner's compressor or your hot water heater to reduce loads); that's the "smart grid" in a nutshell.

 

[BrownTown]

pumped hydro is really the only meaningful storage large scale mechanism for storing energy. It is pretty much exactly what you are talking about though.

 

[SickBeast]

Thanks for the responses everyone.

I had the idea last night and it seemed useful. I guess they won't really need to use ideas like this until wind power becomes more prominent. For now they can just take a coal plant off-line if it's windy enough outside.

 

[silverpig]

Originally posted by: PlasmaBomb

Originally posted by: KIAman

Originally posted by: silverpig

Originally posted by: Gibsons

Originally posted by: SickBeast
What if wind turbines powered an electric motor to hoist up a very heavy object and then sit it on a ledge. Once the wind dies down, that object (attached to a pully) could generate electricity using gravity.

Is this not a simpler solution than storing excess wind energy using batteries?

A flywheel might be a better way. Or maybe even electrolysis.

Flywheels are an excellent way to store power for relatively short periods of time. In fact, I think you can get commercially available flywheels for your house to store your solar/wind power from the day.

I agree. My work implements massive flywheels spinning at 60,000 RPM in a magnetic vacuum to give power to our data center in the event of a power loss. Every DRP (disaster recovery plan) simulation has ran flawlessly.

WTH is a magnetic vacuum? I think you mean vacuum, since any air would quickly slow something running at 60k rpm.

Magnetic bearings, vacuum chamber.

We have turbopumps at work that get up to 56krpm and will keep spinning for quite some time unless you let a little gas in for it to work against if you want to open the vacuum chamber.

 

[Cogman]

Originally posted by: wwswimming

Originally posted by: SickBeast
What if wind turbines powered an electric motor to hoist up a very heavy object and then sit it on a ledge. Once the wind dies down, that object (attached to a pully) could generate electricity using gravity.

Is this not a simpler solution than storing excess wind energy using batteries?

actually that's such a good idea it's already in use ... sort of.

pumped water storage involves pumping water to a height & then re-capturing its energy when it's released.
http://en.wikipedia.org/wiki/P...orage_hydroelectricity

of course there can be problems with regulators
http://earth2tech.com/2009/05/...a-heck-of-a-long-time/

Ok, I hate this idea. It is marketed as an "energy saving method" When in fact it is an energy wasting method. They say it saves energy by pumping on non-peak hours. I say it wastes energy by making non-peak hours, peak hours. (that and the whole laws of thermal dynamics thing).

Sure, the company can make money off of it. that will work. buying low and selling high is a basic money making ability. However, I don't like it when they market it as a "green" solution.

 

[KIAman]

Originally posted by: Gibsons

Originally posted by: PlasmaBomb

Originally posted by: KIAman

Originally posted by: silverpig

Originally posted by: Gibsons

Originally posted by: SickBeast
What if wind turbines powered an electric motor to hoist up a very heavy object and then sit it on a ledge. Once the wind dies down, that object (attached to a pully) could generate electricity using gravity.

Is this not a simpler solution than storing excess wind energy using batteries?

A flywheel might be a better way. Or maybe even electrolysis.

Flywheels are an excellent way to store power for relatively short periods of time. In fact, I think you can get commercially available flywheels for your house to store your solar/wind power from the day.

I agree. My work implements massive flywheels spinning at 60,000 RPM in a magnetic vacuum to give power to our data center in the event of a power loss. Every DRP (disaster recovery plan) simulation has ran flawlessly.

WTH is a magnetic vacuum? I think you mean vacuum, since any air would quickly slow something running at 60k rpm.

and heat it up substantially... I suspect he means magnetically suspended within a vacuum (?). Hard to imagine a better way to reduce friction.

KIAman, just how massive are your flywheels? tons? At 60k, they need to be made from a very strong material, right? Biological rotors that go that fast are usually made out of titanium. "catastrophic failure" is pretty scary with these things.

Yeah, sorry, magnetic bearings inside a vacuum. The flywheels we use are 53 pounds and made of carbon fiber and it actually spins around 52k RPM. We've got 12 of these in our datacenter and each unit can disperse 190KW for 10 seconds max.

You can't actually see the flywheel itself. It's just a huge box with a tiny LCD in the front giving it's status.

Catastrophic failure on these should be interesting, considering they have a design life of over 20 years!

 

[Gibsons]

Originally posted by: KIAman

Yeah, sorry, magnetic bearings inside a vacuum. The flywheels we use are 53 pounds and made of carbon fiber and it actually spins around 52k RPM. We've got 12 of these in our datacenter and each unit can disperse 190KW for 10 seconds max.

You can't actually see the flywheel itself. It's just a huge box with a tiny LCD in the front giving it's status.

Catastrophic failure on these should be interesting, considering they have a design life of over 20 years!

Interesting.... I guess since no one ever handles the rotors or opens/closes the chamber, things are much longer lived.

I've been in the next room when an ultra went off, it's a little scary. Our failure wasn't nearly as bad as these:
Text
Text

In our case, something electrical went wrong with a temperature probe - it shorted/burned or something like that, so the chamber lost vacuum. The rotor then floated off/removed itself from the spindle. The chamber managed to keep the rotor inside, but the whole ~1,000 lb centrifuge jumped a few inches to one side.

 

[silverpig]

Originally posted by: Gibsons

Originally posted by: KIAman

Yeah, sorry, magnetic bearings inside a vacuum. The flywheels we use are 53 pounds and made of carbon fiber and it actually spins around 52k RPM. We've got 12 of these in our datacenter and each unit can disperse 190KW for 10 seconds max.

You can't actually see the flywheel itself. It's just a huge box with a tiny LCD in the front giving it's status.

Catastrophic failure on these should be interesting, considering they have a design life of over 20 years!

Interesting.... I guess since no one ever handles the rotors or opens/closes the chamber, things are much longer lived.

I've been in the next room when an ultra went off, it's a little scary. Our failure wasn't nearly as bad as these:
Text
Text

In our case, something electrical went wrong with a temperature probe - it shorted/burned or something like that, so the chamber lost vacuum. The rotor then floated off/removed itself from the spindle. The chamber managed to keep the rotor inside, but the whole ~1,000 lb centrifuge jumped a few inches to one side.

I've heard of turbopump accidents where they basicallly rip the entire flange off the vacuum chamber they are attached to.

 

[beginner99]

Originally posted by: Cogman
Ok, I hate this idea. It is marketed as an "energy saving method" When in fact it is an energy wasting method. They say it saves energy by pumping on non-peak hours. I say it wastes energy by making non-peak hours, peak hours. (that and the whole laws of thermal dynamics thing).

Sure, the company can make money off of it. that will work. buying low and selling high is a basic money making ability. However, I don't like it when they market it as a "green" solution.

Of course someone makes money with this else nobody would do it.

Still it makes alot of sense to regulate power. Bigger plants and especially nuclear plants can't just lower their output. That's not feasable. So it's easier to pump it up and then use it in "power rush hour" when you do not have enough power just from our big plants.
And the pumping itself wasted pretty little energy.

As already posted this is the only large-scale way of storing electricity. That's why solar, wind,... and any similar unpredicatable energy source are not more common now. usually a large wind-farm has a coal plant associated with it to balance output. So widn energy is therefore not free of CO2 emission vene if it is indirect!

 

[NeoPTLD]

Flywheel systems are infinitely superior to batteries as they can charge as fast as the switchable motor/generator allows, so you can make the wind generators run at maximum output when wind is available. With a battery based system, the cells limit how quickly they can accept a charge.

Flywheel UPSs provide more energy storage per weight than lead acid and maintenance is much lower. Most of the maintenance energy is consumed for powering the levitation electromagnets for bearings.

 

[OUCaptain]

This is why I want a nice plot of land on a hill. I want to build a large pond at the top of the hill and use a windmill or turbine to pump the water to the top pond. Then use the water falling down a pipe to generate the electricity. The system capacity is as big as I can make the pond. Just a similar idea I've been tossing around the noodle bin.

 

[Matt1970]

On these scales, you are best off from both an energy loss standpoint as well as an economical standpoint to sell back to the utility company any excess energy during high wind times and then just rely on the untilities during low wind times.

I think almost all Utility Companies are required by law to buy any excess electrical power you may have and want to provide to them.

Most people with Solar Panels sell excess power to the grid/utility company during the day and that more than offsets the cost of the use of the the grid at night.

 

[William Gaatjes]

Is this feasible ?

If we would take a lot of parabolic collectors.

(A parabolic collector consists of an array of mirrors focused on a singular point, which they heat to a high temperature. By placing water or another liquid at the collector, energy can be stored in the form of a phase transformation, and later harvested through a turbine generator.)

We use the concentrated sunlight to pump water back into a reservoir by means of convection and evaporation. The water evaporates and condensates above the reservoir.
I wonder if this is possible on a large scale. It would be like a hydrodam but with the added value that the concentrated sunlight would be used to to get the water back into the reservoir by means of evaporation. It would ask for a lot of knowledge on fluid behaviour.


EDIT :

Forgot to say that this can be combined with windmills as well. Then possibly a semi-closed system could be created.

 

[PowerEngineer]

Originally posted by: Matt1970
On these scales, you are best off from both an energy loss standpoint as well as an economical standpoint to sell back to the utility company any excess energy during high wind times and then just rely on the untilities during low wind times.

I think almost all Utility Companies are required by law to buy any excess electrical power you may have and want to provide to them.

Most people with Solar Panels sell excess power to the grid/utility company during the day and that more than offsets the cost of the use of the the grid at night.

Essentially true. Most utility companies that I am familiar with do have programs to effectively buy back excess power from residential customers who install wind/solar generation at the same rate charged for power delivered (usually called something akin to "net metering"). This can, however, increase costs for the utilities (and therefore for their other customers); insignificant given the small numbers doing it today, but will become noticable if lots of people do it.

 

[silverpig]

Originally posted by: PowerEngineer

Originally posted by: Matt1970
On these scales, you are best off from both an energy loss standpoint as well as an economical standpoint to sell back to the utility company any excess energy during high wind times and then just rely on the untilities during low wind times.

I think almost all Utility Companies are required by law to buy any excess electrical power you may have and want to provide to them.

Most people with Solar Panels sell excess power to the grid/utility company during the day and that more than offsets the cost of the use of the the grid at night.

Essentially true. Most utility companies that I am familiar with do have programs to effectively buy back excess power from residential customers who install wind/solar generation at the same rate charged for power delivered (usually called something akin to "net metering"). This can, however, increase costs for the utilities (and therefore for their other customers); insignificant given the small numbers doing it today, but will become noticable if lots of people do it.

When I was doing research on it the utility companies don't buy the power back at retail rates, rather at wholesale rates.