Energy storage.

**Vosh** · Dec7-03, 01:00 PM

Alright, class, I'd like everyone to list all the ways energy can be stored.

**Bunting** · Dec8-03, 07:35 AM

how do you mean ? I mean everything technically is Energy, as mass is energy in another form. So energy can be sotred as mass i guess is the big one . o0

If this is some kind of "secretly get people to do your homework" thread (which it would seem to be) then i guess you should ask in the homework forum. I dunno the guidelines or owt like that for rules of asking homework help, but its not very useful if you just copy answers that somebody else has told you!

**russ_watters** · Dec8-03, 10:09 AM

Agreed - Vosh, why don't YOU start by listing a bunch.

**Vosh** · Dec8-03, 05:27 PM

This is not about homework and I was having trouble thinking of a way to ask my question. As an aside, if it was about homework, what's the big deal with just providing answers for someone to copy down (in the homework thread)? That question likely goes in another forum...

Lately I've been trying to figure out all the ways a person can store energy. The first one that comes to mind is, chemically, with batteries. Wound springs, though I don't like that one because springs wear down and seem only useful on very small scales, such as in wrist watches. Ahhh, let's see, there's the fly wheel; erm,

The idea is if you didn't have petrol on hand or something like that, how could you go about storing energy when you need to expend a lot of it in a short period of time (batteries have power but can only be trickled out whereas petrol can expend a lot in short time; taking the energy that trickles out of a battery and storing it so you can use it to power something that needs a lot of energy right now is what I'm interested in --- oh, that reminds me of a capacitor, which releases all it's energy in an instant).

Oil from the ground seems simple, chemically. I wonder why it isn't possible to just synthesize it (although the environment might be in trouble if that happened!) Note: I have no formal science training so some of my questions betray gaping areas of ignorance. Thank you.

**chroot** · Dec8-03, 05:41 PM

Originally posted by Vosh
batteries have power but can only be trickled out

A standard 12-volt car battery can provide several hundred amps of current, or at least several thousand watts of power. How is this "a trickle?" You can easily build electric cars with batteries.

that reminds me of a capacitor, which releases all it's energy in an instant

Also false. Like batteries, capacitors have series resistance, which limits the amount of current they can source or sink.

I wonder why it isn't possible to just synthesize it

It is possible to synthesize it. However, synthesizing it requires energy input -- which you then reclaim when you burn it. When you synthesize petroleum, you're not "making" any energy -- you're just storing energy you already have in the form of chemical bonds. The whole point of us going to find petroleum in the ground is because that petroleum is a pre-existing energy source.

- Warren

**Vosh** · Dec8-03, 06:34 PM

Originally posted by chroot
A standard 12-volt car battery can provide several hundred amps of current, or at least several thousand watts of power. How is this "a trickle?" You can easily build electric cars with batteries.

Easily? You can't run a washer or refridgerator or heater very well, can you? I can hear someone saying, "what about going up hills; recharging...?"

Also false. Like batteries, capacitors have series resistance, which limits the amount of current they can source or sink.

Sure. So is it true that I couldn't run, say, a quartz space heater with a battery?

It is possible to synthesize it. However, synthesizing it requires energy input -- which you then reclaim when you burn it.

I was trying to imagine collecting solar energy and making it right now as oppose to millions of years using the natural method. Ofcourse I imagine someone thought of that; I just wonder how the story goes. If someone were to ask me, I want to know what to tell them...

Many thanks.

**chroot** · Dec8-03, 06:54 PM

Originally posted by Vosh
Easily? You can't run a washer or refridgerator or heater very well, can you? I can hear someone saying, "what about going up hills; recharging...?"

Of course you could. You couldn't run a 1200 W space heater for very long, though. A 1200 W space heater would deplete a 12 V 50 A-h battery in 30 minutes.

Sure. So is it true that I couldn't run, say, a quartz space heater with a battery?

I'm not sure what a "quartz" heater is, but you can run any kind of space heater with a battery with no problem.

Point of fact: batteries are actually KNOWN and USED specifically for their large current-handling capability. In a fuel-cell powered car, batteries are used a storage buffer for energy generated by the fuel cell. The battery can supply large amounts of transient current for acceleration.

I was trying to imagine collecting solar energy and making it right now as oppose to millions of years using the natural method.

The earth recieves about 1 kW per square meter of energy from the Sun. This is the ultimate limit for any kind of solar power, no matter how it is stored and subsequently used.

- Warren

**Vosh** · Dec8-03, 08:38 PM

Originally posted by chroot
I'm not sure what a "quartz" heater is, but you can run any kind of space heater with a battery with no problem.

When I was a kid we had these, I suppose they were 2.5, 3 foot tall narrow heaters that contained two quarts rods that turned red hot when you turned the device on. My assumption is that if you tried to use on of those with a car battery that you'd be recharging that battery every 15 minutes, if you get my meaning.

The earth recieves about 1 kW per square meter of energy from the Sun. This is the ultimate limit for any kind of solar power, no matter how it is stored and subsequently used.

Intriguing. Unfortunately I don't know how to translate that into however many thimbals of oil...

**russ_watters** · Dec8-03, 09:54 PM

Originally posted by Vosh
[b]Originally posted by chroot
My assumption is that if you tried to use on of those with a car battery that you'd be recharging that battery every 15 minutes, if you get my meaning.

Your original statement was about how fast you could take the power out (that was the point of a comparison to a capacitor). A car battery has such low internal resistance that you can get the power out of it VERY quickly - several hundred amps.

The fact that at 100 amps, you'd deplete a battery quickly is simply a matter of density or capacity. Different issue.

Anyway, other ways to store power:

Gravity: in PA, there is a pumping station that uses cheap off-peak power to pump water uphill to a reservoir in order to reclaim the energy during on-peak hours.

Also, you mentioned chemical storage - there are LOTS of different types of chemical storage. Fuel cells, rocket fuel, matches.

Thermal storage: a prototype solar plant heats up liquid sodium (its a metal) to store heat overnight for continuous power. Ice. Your hot water heater. The air in your room. You socks.

**Guybrush Threepwood** · Dec9-03, 03:13 AM

Originally posted by Vosh
The idea is if you didn't have petrol on hand or something like that, how could you go about storing energy when you need to expend a lot of it in a short period of time ......

you mean verrrry much energy in verrrrry short time?
You could try an H-bomb.....

**Artman** · Dec9-03, 12:01 PM

Originally posted by russ_watters

...Anyway, other ways to store power:

Gravity: in PA, there is a pumping station that uses cheap off-peak power to pump water uphill to a reservoir in order to reclaim the energy during on-peak hours.

Also, you mentioned chemical storage - there are LOTS of different types of chemical storage. Fuel cells, rocket fuel, matches.

Thermal storage: a prototype solar plant heats up liquid sodium (its a metal) to store heat overnight for continuous power. Ice. Your hot water heater. The air in your room. You socks.

Russ has some good practical answers here. Such as creating potential energy by raising weight either by using off peak electric power or manually, such as winding a spring or raising a weight.

I think he was also trying to say ice storage for cooling there at the end, but his post isn't very clear. (Fall asleep while writing there at the end Russ?[:)] "Quote from Russ ...Ice. Your hot water heater. The air in your room. You socks.")

Hybrid forms of electric cars are becoming commercially available. These use gasoline to accelerate and electric motors to power the moving car. Some use gasoline to turn extremely high speed, low resistance turbines or flywheels to generate electricity or supplement the motion of the car to generate power to run the electric motors that move the car. They also use regenerative braking to generate electric power from applying the brakes to stop a car.

**russ_watters** · Dec10-03, 05:39 PM

Originally posted by Artman
I think he was also trying to say ice storage for cooling there at the end, but his post isn't very clear. (Fall asleep while writing there at the end Russ?[:)]

No, I just didn't explain. Anything that has around it a barrier to the movement of energy can be considered a container for storage:

Your walls prevent heat from moving in and out of your house, storing thermal energy in it.

Your hot water heater stores hot water to avoid needing to heat it as you use it.

Ice is stored thermal/chemical energy, released in a glass of iced tea.

And your socks of course, store your body's internal thermal energy, keeping your toesies warm.

**Artman** · Dec10-03, 10:19 PM

Originally posted by russ_watters
No, I just didn't explain. Anything that has around it a barrier to the movement of energy can be considered a container for storage:

Your walls prevent heat from moving in and out of your house, storing thermal energy in it.

Your hot water heater stores hot water to avoid needing to heat it as you use it.

Ice is stored thermal/chemical energy, released in a glass of iced tea.

And your socks of course, store your body's internal thermal energy, keeping your toesies warm.

True. Now I get what you were saying. All good points. I just wasn't following your thought.

**young e.** · Dec11-03, 01:02 PM

I dont understand what u mean but anyway there are several ways of storing energy.

1. Storing potential energy by lifting a kg. of block

2. Storing potential energy by stretching a rubber band.

3. Storing energy in an electric field by applying an electric potential to two metal plates which is separated by a certain dielectric.

4. Storing energy in the magnetic field by having an insulated wire turned and making toroid solenoid and the like.

This is but just a few examples of storing of energy but in the qoute that u put in your message to us I think you don't believe that this things are possible. To see is to believe that is how i understood ur message, anyway if u dont see this things just try to feel it and have consequence with the law of nature----enough said. Thanks!

**wimms** · Dec13-03, 11:40 AM

Originally posted by russ_watters
Anything that has around it a barrier to the movement of energy can be considered a container for (energy) storage.

Interesting generalisation. Made me think of several things.

Barrier is any "resistence" to free energy flow. It can be mechanical container, but no problem also to think of electric or magnetic force, gravity. Indeed, gravitating object resists free energy flow, its thus container. Curvature of space itself is energy storage, not just the object creating it.

Interesting to note that superconductor is not energy storage by this count. Much like flat vacuum isn't. Yet superconductors have been used to store huge amounts of currents. It must then be to do with spatial aspect of interactions? Obviously, energy is stored in the fields around it, not in the superconductor.

**russ_watters** · Dec13-03, 10:59 PM

Superconductors are used for storage? How so.

And I mentioned gravitational storage above.