mechanical energy storage

The wave action electrical generators do not look like they would be that hard to replicate upon a small scale.

Incidentally, they started to make a dam across the Bay of Fundy in Maine in the 1950's, but the project stalled and was never restarted.

I often thought that a wind/mechanical alternative might exist where a large tree (preferably a conifer with its large evergreen boughs), would be attached to multiple lines. As the wind blew and tossed about the top of the tree, the lines would pull through mechanical gears that would generate electricity. When the wind let off, or blew in another direction, springs would automatically retract the lines...think of it as a big recoil, like starting a small gasoline engine. Because the lines were attached in multiple directions, no matter which way the wind came, power would be generated.

About the only major cost would be configuring the recoils and attaching them to a generator.

I think there is some potential energy to be gleaned from a 80 foot tree with its boughs catching a fair square footage of wind. Add in the leverage of 80 feet and that is some serious torque.

I think something to factor into storage is power (energy/time) in addition to just energy. A storage system that is low power (building up it's energy slowly over a longer time) is likely best suited to a load that uses low power (depleting it's energy slowly). It's possible to go counter to this - deplete the storage quickly, re-build very slowly - but often this is where finding a practical application of non-battery storage systems runs into problems.

Someday I'd like to go back and take a look at pre-grid farming tech. At that time, the wind/battery 24V system seemed to be the winning solution. I'm not aware of what it's technological competitors were at that time.

If you all haven't heard of Living Energy Farm in Virginia (I think they branched off from Twin Oaks a while back)
They run a lot of motors and machinery directly off of 180V solar- no batteries, no inverters, no charge controllers I think.
Then for low power loads they use a few Ni-Fe batteries.
I'm really not doing justice to what they seem to be doing IMO.  I didn't know so much could be done directly with 180V power.  Also, their thermal storage systems seem unique.

Travis Johnson wrote:I often thought that a wind/mechanical alternative might exist where a large tree (preferably a conifer with its large evergreen boughs), would be attached to multiple lines. As the wind blew and tossed about the top of the tree, the lines would pull through mechanical gears that would generate electricity. When the wind let off, or blew in another direction, springs would automatically retract the lines...think of it as a big recoil, like starting a small gasoline engine. Because the lines were attached in multiple directions, no matter which way the wind came, power would be generated.

About the only major cost would be configuring the recoils and attaching them to a generator.

I think there is some potential energy to be gleaned from a 80 foot tree with its boughs catching a fair square footage of wind. Add in the leverage of 80 feet and that is some serious torque.

Having tied a few things to trees in the past, it's something I avoid if possible now. Some type of interface to the soft wood found on top of the tree may prove difficult, at least that's my experience.
Perhaps if you located a Porcupine damaged tree where the top is dead and somehow get to the top of the tree to create that cable to tree interface?
I love this idea. If I'm getting what Mollison is saying in the first chapters while we're observing we can create tests and collect data. I'd need imagine where the tech is now there are data loggers you could setup on the ropes attached to the top of the tree. See how much energy is available and what types of energy is present. Torgue, velosity, acceleration, etc.
It probably shows, but I just watched a video of a guy testing the efficiency of three fan blade shapes:

Fascinating results, and not what I expected at all.
Brian  

Andrew Butt wrote:I think something to factor into storage is power (energy/time) in addition to just energy. A storage system that is low power (building up it's energy slowly over a longer time) is likely best suited to a load that uses low power (depleting it's energy slowly). It's possible to go counter to this - deplete the storage quickly, re-build very slowly - but often this is where finding a practical application of non-battery storage systems runs into problems.

Someday I'd like to go back and take a look at pre-grid farming tech. At that time, the wind/battery 24V system seemed to be the winning solution. I'm not aware of what it's technological competitors were at that time.

Sadly, a lot of it was actually petroleum based. Gasoline was plentiful and cheap, though they also used distillates and kerosene. I know many old dairy farms around here burned when their gasoline milk tank coolers sparked a fire in the old timber frame barns. The grid did not reach here until the 1940's or so.

Here's another idea for a general principle that could be harnnessed, but it probably has lots of downsides. I call "The Archimedes."

You have a really big tub, it could be a pond, midway up a hill.  It is dammed, hence the tub analogy, or you have a "monk" (Sepp Holzer's invention, an L-shaped pipe that lets you adjust the level of water in a pond by rotating it around the more horizontal axis).  You have a raft in it with a huge, huge weight, such that it barely floats.  When it rains, your raft goes up.  And it's got a rope in its center, and the rope is on a ratchet.  This would have to be very strong, and there would have to be some kind of tower  and a pulley (another cost) and a small counterweight to get it to ratchet up.  (When it's not raining, you can also pump water into the tub with solar or wind-powered or Nike pumps, whatever you've got.) (Nike pumps are just fashion, they don't actually pump water, that was a joke).

Now, when you want power, you open the dam/rotate the monk and use the water for power there, but the raft is left up high.  When you need backup power, you unlock the ratchet and the raft drops, and use the weight of the falling raft (or the rope it's pulling) to turn a turbine for more energy.

The advantages:
--you can get a sudden surge of power with this raft dropping, as compared with the flow of the water turning a turbine (it's impossible to tie a huge block of water to a rope, but you can tie a raft to a rope).
--you have a backup power supply
--you concentrate energy from an entire hillside uphill of you into one pond (not different from a regular dam in this regard)
--it looks kinda cool
--maybe having less of the energy generation be from opening the dam and more from

Disadvantages:
--total energy is not higher than a dam in this situation, far as I can tell
--it uses a bunch of extra resources to make a big-ass, strong tower and rope and ratchet
--hard to pull a pin out of the gear of the ratchet to operate the thing, I guess
--the fish and other water citizens are going to have a fit
--Greenpeace will probably also have one
--...probably lots of other stuff I haven't thought of

Just a brainstorm, anyone see merits in this general principle? could it be developed in some other way?

The gyroscope storage mechanism thing is interesting--because the power goes as the square of the rotation speed, I believe, and only as varies directly as the mass, you can just get it going faster and faster.  If you can store in a vacuum, or handle friction in some way, then it can theoretically be tiny and still store a British Buttload Unit of power.  

I imagine using an atom this way...spinning it faster and faster...but then the bouncing up against other atoms probably causes problems, and maybe you run into the speed of light speed limit and get a ticket.  

I hear hospitals use gyroscopes.

And they used to have them on streetcars in the 50's in Switzerland, but they were too heavy and they broke.  (Why didn't they make them faster instead of heavier?)

Speaking of streetcars, I think if you're going to use compressed air, why not power it without motors, just have it fart out the back? like when you open a balloon and it goes flying across the room.  

Yeah, they do those things. I didn't know about the voltage.  The solar appliances just automatically turn off at night--which also avoids human error and crosses something off your to-do list.  

They were having some obstacles with thermal storage for high heat when I was there, have they made a breakthrough? there was a solar barbecue some people put up on kickstarter a few years ago, but then they had problems with their storage mechanism.  


Please tell more details if you can!  The folks at Living Energy Farm don't really get on line much and so it's especially great to hear any updates about their progress.  THey're hardcore about having a small footprint.

Nathan Allen Lewis wrote:If you all haven't heard of Living Energy Farm in Virginia (I think they branched off from Twin Oaks a while back)
They run a lot of motors and machinery directly off of 180V solar- no batteries, no inverters, no charge controllers I think.
Then for low power loads they use a few Ni-Fe batteries.
I'm really not doing justice to what they seem to be doing IMO.  I didn't know so much could be done directly with 180V power.  Also, their thermal storage systems seem unique.

[quote=Joshua Myrvaagnes]Here's another idea for a general principle that could be harnnessed, but it probably has lots of downsides. I call "The Archimedes."?[/quote]

Your idea has merit, and is currently being done, and I thought of doing it myself...it is just that you are using the wrong medium...your idea uses water while the one I know is working, and the one I would use, would be using air.

I believe it is in Australia they are doing this, but basically they built a multi-acres upside down funnel out of plastic sheeting and a frame. As the air inside the "funnel" rises, it is funneled through a turbine that spins and produces electricity. At night, when the air cools, it passes back through the turbine and generates electricity. In this way it is like a tidal basin, only it uses air pressure instead of water to ebb and flow.

Could crops been grown in greenhouse-like fashion under the funnel as well?

Joshua- Sorry, I haven't been to Living Energy- just what I've read from their website.
I'm not sure what you're referring to as far as the solar barbecue.  I use the Rand solar oven (like $70 or so on Amazon or eBay).  The latest one is working quite well.  I've got YouTube videos up (as do a lot of other people now).

The re gen on an electric car uses gravity to recharge the battery in much the same way, going down hillsides and slopes, does it not? So using this same technology does seem to have potentials already in use.

Nathan Allen Lewis wrote:Joshua- Sorry, I haven't been to Living Energy- just what I've read from their website.
I'm not sure what you're referring to as far as the solar barbecue.  I use the Rand solar oven (like $70 or so on Amazon or eBay).  The latest one is working quite well.  I've got YouTube videos up (as do a lot of other people now).

The solar bbq would capture heat by day and fight crime by night---you could barbecue when it was dark for up to two hours!  They had a "patented substance" for the thermal battery.  Don't know what.  Does yours do that?

That sounds great too !  Though a little different from what I had in mind. Let me try to clarify, the main part of my idea was the "pull the plug on the bathtub and let the water drain out, then the weight is left high and dry"


[quote=Travis Johnson][quote=Joshua Myrvaagnes]Here's another idea for a general principle that could be harnnessed, but it probably has lots of downsides. I call "The Archimedes."?[/quote]

Your idea has merit, and is currently being done, and I thought of doing it myself...it is just that you are using the wrong medium...your idea uses water while the one I know is working, and the one I would use, would be using air.

I believe it is in Australia they are doing this, but basically they built a multi-acres upside down funnel out of plastic sheeting and a frame. As the air inside the "funnel" rises, it is funneled through a turbine that spins and produces electricity. At night, when the air cools, it passes back through the turbine and generates electricity. In this way it is like a tidal basin, only it uses air pressure instead of water to ebb and flow.

Could crops been grown in greenhouse-like fashion under the funnel as well?

[/quote]

With the air funnel, how much energy is produced?
It's neat that it doesn't seem to have the problem of air compression and expansion(heat and cooling)

[quote=Joshua Myrvaagnes]That sounds great too !  Though a little different from what I had in mind. Let me try to clarify, the main part of my idea was the "pull the plug on the bathtub and let the water drain out, then the weight is left high and dry"


[quote=Travis Johnson][quote=Joshua Myrvaagnes]Here's another idea for a general principle that could be harnnessed, but it probably has lots of downsides. I call "The Archimedes."?[/quote]

Your idea has merit, and is currently being done, and I thought of doing it myself...it is just that you are using the wrong medium...your idea uses water while the one I know is working, and the one I would use, would be using air.

I believe it is in Australia they are doing this, but basically they built a multi-acres upside down funnel out of plastic sheeting and a frame. As the air inside the "funnel" rises, it is funneled through a turbine that spins and produces electricity. At night, when the air cools, it passes back through the turbine and generates electricity. In this way it is like a tidal basin, only it uses air pressure instead of water to ebb and flow.

Could crops been grown in greenhouse-like fashion under the funnel as well?

[/quote][/quote]

[quote=Joshua Myrvaagnes]That sounds great too !  Though a little different from what I had in mind. Let me try to clarify, the main part of my idea was the "pull the plug on the bathtub and let the water drain out, then the weight is left high and dry"[/quote]

Oh no, I understood perfectly, it is just that your system uses heavy water with gravity to make the shift from high to low and back, where as the air funnel system uses thermodynamics to change the air density to make the shift from low to high and back.

I am a huge fan of liquid thermodynamics, I really am, it is just in this situation I think it would be much less effecient. Because air is 600 times less dense then water, it is a bit easier to work with. Normally in the heating systems I work with, boilers are more effecient then hot air furnances because of this density, but in this case I do not think there is an advantage. The difference here is, you must use hydraulics to lift a floating weight , then convert that dropped weight (kinetic energy) into electricity via the generator. With the air funnel system, it just passes back and forth through the generator fan blades. It is that extra step involved with they hydraulic system that losses are incured.

Whether or not building earth works to retain water, bring in water, and then release that water is cheaper in infrastructure costs then building a plastic tent to trap heated or cooled air...I am not sure. I am sure everything would be super-site dependent though, just as it would be with th air funnel.

I would love to try it, but I am not sure Maine is the place. Since the air funnel is nothing more than a Striling Engine...just several acres in size... a place that gets hot and then cold daily would be better then frigid Maine. We have already gotten snow here (October 16th 2018)

The solar bbq would capture heat by day and fight crime by night---you could barbecue when it was dark for up to two hours!  They had a "patented substance" for the thermal battery.  Don't know what.  Does yours do that?


No, it just retains heat with two layers of glass with a vacuum in between like a thermos. The inner layer is black to absorb.  It does retain heat very well, though.  The GoSun is the more expensive version and I think they added something to cook after dark, but I haven't checked.

I'm planning on storing energy in a 40 ton water tank by removing energy in summer from the house to the tank and then using that energy in winter to heat the home.

Yen Yus wrote:I'm planning on storing energy in a 40 ton water tank by removing energy in summer from the house to the tank and then using that energy in winter to heat the home.

Is this tank going to be underground?  So a closed loop geothermal heat pump?

Concrete flywheels are coming, and they are due to outcompete chemical batteries for stationary applications:


(English subtitles available)  

https://fr.wikipedia.org/wiki/Volant_de_stockage_solaire

Burra Maluca wrote:The video in that link was rather interesting.  I've embedded it here.

I noticed that the bottom barrels are circled and cinched, probably to prevent them crapping under the weight of other barrels? Who goes up there to un-cinch them so the crane can let them down gently? What power is used to lift these barrels? considering the weight, a lot of energy is used there, so from which "surplus electricity" exactly are you drawing?
Every time we convert mechanical energy into electricity, we lose some energy. [friction loss] That is true of every conversion from one type of energy into any other type of energy.
I have been quite impressed with the Ryobi batteries or Ryobi type that I am now using for everything: chain saw, drills, weed-eater, blower. My local Electric company is weaning itself from coal to wind. [About one third is coming from "renewables"now.] I hope they add sun too. It is their electricity that I use to recharge these batteries. and it takes only 20 minutes to recharge.
If I were God the Master and had the money to match, I would invest more in battery storage capability. [OK: If I were God the Master, I would not need money, but you know what I'm getting at ;-)]
Another problem is that on my land, I do not have a crane, nor do I have the money to buy one, but I can see where commercially, that could be a possibility.

Fred Daran wrote:Concrete flywheels are coming

That video was completely devoid of technical performance figures. If I was pushing an invention like his, that's the first thing I'd mention. Very suspicious.
I don't fundamentally oppose this technology, but if it works, the numbers need to be provided.

EDIT: What I want to know is: how much energy the flywheel can store (in Joules or Watt Hours); how physically large the flywheel is; what the cost per kiloWatt hour to the end consumer will be.

Mike Lang wrote:What I want to know is: how much energy the flywheel can store (in Joules or Watt Hours); how physically large the flywheel is; what the cost per kiloWatt hour to the end consumer will be.

Hi Mike,

The speaker mentions a cost of 0.02 €/kWh for his concrete flywheels at 6:15.

This info can also be found in the slides:
0:35  Solar energy production : 0.02€/kWh
2:36  Solar + chemical batteries : 0.12€/kWh
           (so chemical batteries cost 0.10€/kWh)
6:16  Solar + concrete flywheel : 0.04€/kWh
         (so concrete flywheels cost 0.02€/kWh)

As for flywheel capacity, check out the company website:
http://www.energiestro.net/products/

Capacity	Diameter	Height	Mass	Power
	(m)	(m)	(ton)	(kW)
10 kWh	1,0	1,5	3,0	10
20 kWh	1,3	1,9	6,0	20
50 kWh	1,7	2,6	15	50
100 kWh	2,2	3,2	30	20
1 MWh	4,6	7,0	300	200

I will go for the wind up device as in clockwork mentioned by Dan above. I have this recurring dream of constructing a huge wind up device that can be winded by wind solar or wave. Actaully it can be use for a variety of small gadget like light and radio We just have to scale it up as needed.

http://theconversation.com/trevor-baylis-the-wind-up-radio-inventor-who-forced-companies-to-take-sustainable-design-seriously-92967

https://www.amazon.com/Wind-Up-Lantern-Flashlight-Combo/dp/B000ZHXUFK

Fred Daran wrote:The speaker mentions a cost of 0.02 €/kWh

Thank you, Fred. I was watching the subtitles too closely to see the slides. Re-watching the video, you hear the speaker say "...something something kilowatt hours", but that part is not included in the subtitles.

Chris Kott wrote:

I think heat energy storage is probably much more accessible and practical, though with a few problem issues that need care in the handling. If homesteads can make home-scale thermal power units, converting heat to electricity....

I think you're on the right track: thermal heat storage.  Tamera.org has developed a good solution that can be used on a homestead. Here's how it works:

-heat veggie oil up using a solar concentrator and then store the veggie oil in a well insulated tank;
-when they need mechanical energy or electrical energy, they run their really hot veggie oli thru their stirling engine, Sunpulse 500,  invented by  Jürgen Kleinwächter.  [youtube]https://www.youtube.com/watch?v=v_e0981CLDI[/youtube] [youtube]https://www.youtube.com/watch?v=tYBg3YtWaLo[/youtube].

Some might complain of the complexity of cost but it isn't as expensive as a large lake or dam; your hot veggie oil can even be used to cook with by means of a metal jacket which can fit around your pots.

Metal working is required but what a huge leap over the current methods of storage in terms of low enviromental impact vs batteries or dams.

Nathan Allen Lewis wrote:If you all haven't heard of Living Energy Farm in Virginia (I think they branched off from Twin Oaks a while back)
They run a lot of motors and machinery directly off of 180V solar- no batteries, no inverters, no charge controllers I think.

It looks like they have replaced all the AC motors in their shop tools with 180 volt industrial DC motors.  That's a slick system.  Particularly the part about halving the solar array to get a nominal 90 volts DC for use with common household universal motors.  As an electrician, I can say that the big downside is that DC voltage that high is much more prone to arc-welding the switches closed, and are therefore much more prone to accidents and fires; which is why they are not more common than they are.  There should be a "pull-out" disconnect ahead of their 30 amp safety switches, that can be yanked out by someone in the event that the 30 amp switch welds shut.  A standard forktruck charging connector with a large loop of wire (as both a handle and current carrying conductor) would work well for this.  Also, only use fuses with high voltage DC, as normal breakers cannot be relied upon for DC; and industrial DC breakers cost a fortune.