Weight as a battery?

Guda

Superstrut Strut
Joined
Nov 19, 2019
Messages
516
If you could lift a block with extra power & then when you need the power. By lowering the weight the mass generates power. It’s all in the gearing. Easy up, hard down.

Anyone here smart enough to do the calculations?
 

gnubie

Photon Sorcerer
Joined
Sep 20, 2019
Messages
3,851
Motor / generator efficiency is going to be a problem let alone losses in the control electronics and gearing. You might be looking at 80-90% loss on both in and out with the motor/generator alone, unless special high efficiency construction items.

A lithium battery is going to give better performance and be more convenient in general.
 

upnorthandpersonal

Administrator
Staff member
Moderator
Joined
Dec 25, 2019
Messages
3,090
Location
63 degrees North, Finland
You mean something like this: https://deciwatt.global/gravitylight

Simplifying the math and assuming no losses, you're looking at potential energy Ep = m x g x h (Joules). If we take 1kWh as a target, this makes 3.6MJ. If you take a mass of 10000kg you need to lift that 36 meters to store that. And of course, to get it back, you need a mechanism to slowly release it. In other words, not really practical except for hydro which use this aspect.
 

Craig

Watts are Watts!
Staff member
Moderator
Joined
Sep 20, 2019
Messages
2,825
Location
Hollister CA and off the grid in Idaho
Who cares about the efficiency. If you have extra solar power and a place to raise and lower the weight you have much cleaner energy than battery storage. I think this is a concept that could have serious potential in an off grid situation. Think about it a weight battery would have no low temperature restrictions.
 

gnubie

Photon Sorcerer
Joined
Sep 20, 2019
Messages
3,851
That's fine, if you have the power to burn. Then you just need to make a rather large weight and move it through a rather large distance, or some combination of both. By the time you've built the frame that can bear the weight, or dug a nice deep hole and kitted it out with a sump pump etc, you might just start to think that buying a lithium battery was the wiser choice.
 

Craig

Watts are Watts!
Staff member
Moderator
Joined
Sep 20, 2019
Messages
2,825
Location
Hollister CA and off the grid in Idaho
That's fine, if you have the power to burn. Then you just need to make a rather large weight and move it through a rather large distance, or some combination of both. By the time you've built the frame that can bear the weight, or dug a nice deep hole and kitted it out with a sump pump etc, you might just start to think that buying a lithium battery was the wiser choice.

There is no doubt a lithium battery is cheap and practical. But that is not the question.

I have my solar panels attached to a power pole Having grid power is even cheaper than lithium but it's no fun. :)
 
Last edited:

Guda

Superstrut Strut
Joined
Nov 19, 2019
Messages
516
Motor / generator efficiency is going to be a problem let alone losses in the control electronics and gearing. You might be looking at 80-90% loss on both in and out with the motor/generator alone, unless special high efficiency construction items.

A lithium battery is going to give better performance and be more convenient in general.
The concept is based on this, if a system is scaled for bad weather then the system will be producing a ton of extra power that just gets dumped.

That's fine, if you have the power to burn. Then you just need to make a rather large weight and move it through a rather large distance, or some combination of both. By the time you've built the frame that can bear the weight, or dug a nice deep hole and kitted it out with a sump pump etc, you might just start to think that buying a lithium battery was the wiser choice.
This is probably the most realistic fact. Lifting heavy weight is not going to be cheep.

You mean something like this: https://deciwatt.global/gravitylight

Simplifying the math and assuming no losses, you're looking at potential energy Ep = m x g x h (Joules). If we take 1kWh as a target, this makes 3.6MJ. If you take a mass of 10000kg you need to lift that 36 meters to store that. And of course, to get it back, you need a mechanism to slowly release it. In other words, not really practical except for hydro which use this aspect.
That’s so AWESOME! I love products like that. I hope it was build without product obsolescence.

Who cares about the efficiency. If you have extra solar power and a place to raise and lower the weight you have much cleaner energy than battery storage. I think this is a concept that could have serious potential in an off grid situation. Think about it a weight battery would have no low temperature restrictions.
Right! A fun challenging project. But I think the point about cost is pretty relevant. And if it failed, like boom.....

AWESOME THREAD! Much thx!
 

Craig

Watts are Watts!
Staff member
Moderator
Joined
Sep 20, 2019
Messages
2,825
Location
Hollister CA and off the grid in Idaho
Bad weather that is exactly what my system is set up for. That's why I love the concept. I was more thinking if storing water but that freezes in winter. So lifting some sort or whatever would be a neat solution.
 

FilterGuy

What, me worry?
Joined
Nov 26, 2019
Messages
5,608
Location
Los Gatos CA
The idea of lifting weights to store energy has been explored at utility scale. Imagine using excess electricity to hoist a train full of concrete up a steep incline. When you want power, you let it roll back down and generate power. Pumped hydro has been used all over the world and is essentially the same thing: Pump water (weight) into an elevated reservoir and then use it to generate electricity as it comes back down.

The point of these types of schemes at the utility scale is just that: Scaling. Lithium batteries can be very efficient, but is costly to scale. As the cost of lithium batteries has come down, the equation is changing, but there are still a lot of storage methods that are contenders. With so much solar and wind generation being deployed, the race to develop and deploy grid storage is on. It will be interesting to watch what happens over the next several years.
 

FilterGuy

What, me worry?
Joined
Nov 26, 2019
Messages
5,608
Location
Los Gatos CA
At a DIY scale, Lithium batteries offer a lot of advantages that most mechanical storage schemes lack:
  • Ease of use
  • compactness
  • reliability
  • portability
  • etc
However, I like Craig's point of view. Sometimes you do something 'cuz its fun to do, not because it is practical. You don't have to justify it any more than justifying going to a ball game or a concert.
 
D

Deleted member 783

Guest
Fill a barrel with water and let it leak slowly through a drip system into your garden throughout the day. On a platform with a spring loaded arm, the barrel will lift as the water leaks out. Add a float valve on a timer to refill at night. Simple! I saw this somewhere once and it worked perfectly...can't remember where. It was set up as a solar tracker but the concept is the same.
 

gnubie

Photon Sorcerer
Joined
Sep 20, 2019
Messages
3,851
~
The point of these types of schemes at the utility scale is just that: Scaling. Lithium batteries can be very efficient, but is costly to scale.
~
My state's overnight electricity consumption last night was in the area of 72GWh (6pm - 6am), or to put it in silly terms 7200 million 10 Wh 18650 cells.
 

PHoganDive

Solar Addict
Joined
Sep 20, 2019
Messages
313
Location
Mass, USA
Our town installed a 3MW battery to help smooth out the power load. We already have a good sized solar installation (to the point that there was a moratorium put on home solar installs, as they would further worsen the duck curve created by the high solar capability we have now. The battery will help smooth that out.


1577604520313.png
 

JeepHammer

Photon Sorcerer
Joined
Nov 15, 2019
Messages
875
*If* the above from Up North is correct...

36 METERS TALL structure that can safely lift/hold a 10,000 Kilo mass, and the pulley/winch system to raise the 10,000 kilo mass.

That's 118 FEET tall drop space (18 stories), plus head room for lifting hardware,
Built to SAFELY hold 22,050 POUNDS of mass off the ground 118 Feet in the air.
Since suspended loads need at least 3x the weight being suspend to be safe, that's cables capable of Pounds.
That's 66,150 pound capable cable minimum...

Then you have to produce enough excess energy to get that 22,050 Pound mass back UP the tower, and have a winch capable of doing so, year in-year out, several times a day since the drop only produces 1kWh each trip down...

All that heavy steel to make the power just one Battle Born battery can deliver, one Battle Born battery and 6 hours of sun with a 200 Watt panel.

I just did the math on infrastructure cost and I'll stick to panels & batteries...

More efficient would be a water tower,
Since water wouldn't have to be lifted all at once, pumped slowly so less power support hardware for pumping, and a dozen other reasons, water pump stations are more expensive than solar, but they do work at night through hydro generators, work consistently when solar/wind doesn't...

I guess if you want to build an 18+ story building to host up a 22,050 pound mass to make 1kWh it's your money...
 

upnorthandpersonal

Administrator
Staff member
Moderator
Joined
Dec 25, 2019
Messages
3,090
Location
63 degrees North, Finland
Think about it, let's do a calculation on that GravityLight. With a mass of 10 kg at a height of 1 meter you have about 100 Joules of potential energy (just enough to power an LED for a few minutes), or simplified, 1 kg at 1 meter height gives you 10 Joules. 1kWh equals 3.6 MegaJoules. So, I think my math was right - except for one thing: it's not realistic to extract 100% of this energy into electric energy; it'll be more around 50% - so you need to double the weight or the height for your 1kWh.

If you look at those numbers you realize how much energy that really represents, and how amazing it is that we can store that in a battery in the first place.
 
Last edited:

JeepHammer

Photon Sorcerer
Joined
Nov 15, 2019
Messages
875
Think about it, let's do a calculation on that GravityLight. With a mass of 10 kg at a height of 1 meter you have about 100 Joules of potential energy (just enough to power an LED for a few minutes), or simplified, 1 kg at 1 meter height gives you 10 Joules. 1kWh equals 3.6 MegaJoules. So, the I think my math was right - except for one thing: it's not realistic to extract 100% of this energy into electric energy; it'll be more around 50% - so you need to double the weight or the height for your 1kWh.

If you look at those numbers you realize how much energy that really represents, and how amazing it is that we can store that in a battery in the first place.

Exactly! :)

What do you think Romans or Egyptians would think about the work a single solar panel & battery can do today?
The guy with a hammer & chisel seeing what a power saw can do?
The guy trying to beat grain into powder between two rocks seeing a powered mill?
Half days hard labor done in 3 minutes, almost effortlessly?

When I say I power a machine shop with mostly solar, people think "No Big Deal" or don't think anything at all since they just don't know, the unlimited power from the grid being the 'Normal' and no thought about it all their lives...
Hand them a hand saw, point them at fallen timber and tell them to build a house (or even a dog or bird house) and their jaw drops open, you get 'The Look' and they throw the saw down and walk off (probably thumbing their phone to tell their 'Friends' how insane you are...)

The degree in 'Liberal Arts' is good, all education is good,
But it will never impress me like a Journeyman certification in any trade! ;)

I'll never forget the collage professor that saw us move a house, blowing out the back of concrete blocks with a sledge hammer without caving the face in, lifting the house with levers and wedges,
He kept saying "That shouldn't be possible!"
A bunch of hillbilly grunts lifting and moving an entire house, and later we found out he used the videos to teach his classes about simple leverage, application of force, etc.

With an education, at least he didn't tell us "You Can't Do That!" Like a lot of people did, even though we were doing it right in front of them...
The 'Space Alien' types don't understand what you can do with a lever, rollers and wedges, so it MUST have been aliens! (Insert eye roll here)

I'm NOT building an 19 story building (headroom), a winch system to lift 22,050 pounds of mass, build a gear & generator system to convert motion into electrical energy, etc...
To store 1kWh of energy, I'll just get a battery and solar panel!

Running water would be better than solar, but I don't have free running water across my land.
Sunshine falls on the rich & poor alike, and being a farmer, I look at it like any other 'Crop' that can be harvested to support the homestead/farm.
If I had reasonable wind, I'd try to grab that too! ;)
 
Last edited:

Reed Cole

Solar Enthusiast
Joined
Dec 25, 2019
Messages
119
*If* the above from Up North is correct...

36 METERS TALL structure that can safely lift/hold a 10,000 Kilo mass, and the pulley/winch system to raise the 10,000 kilo mass.

That's 118 FEET tall drop space (18 stories), plus head room for lifting hardware,
Built to SAFELY hold 22,050 POUNDS of mass off the ground 118 Feet in the air.
Since suspended loads need at least 3x the weight being suspend to be safe, that's cables capable of Pounds.
That's 66,150 pound capable cable minimum...

Then you have to produce enough excess energy to get that 22,050 Pound mass back UP the tower, and have a winch capable of doing so, year in-year out, several times a day since the drop only produces 1kWh each trip down...

All that heavy steel to make the power just one Battle Born battery can deliver, one Battle Born battery and 6 hours of sun with a 200 Watt panel.

I just did the math on infrastructure cost and I'll stick to panels & batteries...

More efficient would be a water tower,
Since water wouldn't have to be lifted all at once, pumped slowly so less power support hardware for pumping, and a dozen other reasons, water pump stations are more expensive than solar, but they do work at night through hydro generators, work consistently when solar/wind doesn't...

I guess if you want to build an 18+ story building to host up a 22,050 pound mass to make 1kWh it's your money...

A building sounds extravagant, all you would really need is a 18 story tripod.
 

Reed Cole

Solar Enthusiast
Joined
Dec 25, 2019
Messages
119
Exactly! :)

What do you think Romans or Egyptians would think about the work a single solar panel & battery can do today?
The guy with a hammer & chisel seeing what a power saw can do?
The guy trying to beat grain into powder between two rocks seeing a powered mill?
Half days hard labor done in 3 minutes, almost effortlessly?

When I say I power a machine shop with mostly solar, people think "No Big Deal" or don't think anything at all since they just don't know, the unlimited power from the grid being the 'Normal' and no thought about it all their lives...
Hand them a hand saw, point them at fallen timber and tell them to build a house (or even a dog or bird house) and their jaw drops open, you get 'The Look' and they throw the saw down and walk off (probably thumbing their phone to tell their 'Friends' how insane you are...)

The degree in 'Liberal Arts' is good, all education is good,
But it will never impress me like a Journeyman certification in any trade! ;)

As a stone mason I can confirm that it's much quicker to cut through stone with a saw than with hand tools. Still requires a lot of effort though, I'd rather swing a hammer all day than run a saw if rate of production weren't an issue.
 
Top