Hello,
I want to build a green energy storage system. Where an engine lifts a big mass with the electric energy that is available at the moment, i.e solar/wind/grid. Then release the mass from about 30m - 50m to create an electric energy. Was thinking to use gear transmission to control the speed of the system energy discharge and electric voltage. 

will appreciate an advice on the following:
1. How to I calculate the potential electric energy using the height and mass. 
2. I also want to be able to calculate the time of discharge VS gear transmission VS mass VS height. 
2. any recommendation of a design and parts type to purchase (turbine, dynamo, engines, gear transmission set etc.) will be appreciated.

thanks!  

Well a 1kg mass 1m high has 9.8 joules or potential energy.

9.8 joules is 9.8 watt-seconds.

So to scale this up, 1000kg 50m up in the air has about 490 000 joules of energy, or 136 watt hours.

So it’s not looking too promising....

I think the idea is better suited to get a sudden burst of energy since you can get all 490 000 joules in a very very short time if you drop it!

 

Edited February 22, 20197 yr by Elbow
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20 hours ago, yonatan said:

Hello,
I want to build a green energy storage system. Where an engine lifts a big mass with the electric energy that is available at the moment, i.e solar/wind/grid. Then release the mass from about 30m - 50m to create an electric energy. Was thinking to use gear transmission to control the speed of the system energy discharge and electric voltage. 

will appreciate an advice on the following:
1. How to I calculate the potential electric energy using the height and mass. 
2. I also want to be able to calculate the time of discharge VS gear transmission VS mass VS height. 
2. any recommendation of a design and parts type to purchase (turbine, dynamo, engines, gear transmission set etc.) will be appreciated.

thanks!  

You are right about using a gear or a servo valve. But there is a problem, you have to consider that the source is  delayed respect the load.

So, if I were you,  I would install a small battery in order to stabilize the system, targetting battery Voltage using a PID control.

Also, as Elbow mention, you need a Big mass of water.

Finally, with a PSMM pump and a Kaplan turbine you could have +-60% efficiency.

Edited February 22, 20197 yr by Javi Martínez

The typical thing people want to do is pump water up to a height and let it run down again, drive a Pelton wheel . It's pretty efficient (over 85%), and the math is much the same: 1 liter of water weighs 1kg and at 1 meter has 9.8 Joules of energy. So 1000 liters 100 meters up is 980KJ. There is 3600 joules in a Wh, so So that is 272wh. I need about 4 times that just to keep my beer cold 🙂

Also see below... which is always going around on facebook. No, complete hoax. Put a horse instead of a man on it (a horse will do more than a man), convert 1 horse power to kw, multiply with one hour. Or consider that a good workout is around 700 calories, at something like 35% efficiency (cause the human body has a fairly power-hungry CPU and lots of cooling requirements), and convert that to kwh... 🙂

 

I think It could be done in a Big scale.

Thousands of panels close to a hydro-electric plant.

Edited February 22, 20197 yr by Javi Martínez

Another idea: 

https://qz.com/1355672/stacking-concrete-blocks-is-a-surprisingly-efficient-way-to-store-energy/

2 hours ago, plonkster said:

Also see below... which is always going around on facebook. No, complete hoax. Put a horse instead of a man on it (a horse will do more than a man), convert 1 horse power to kw, multiply with one hour. Or consider that a good workout is around 700 calories, at something like 35% efficiency (cause the human body has a fairly power-hungry CPU and lots of cooling requirements), and convert that to kwh... 🙂

When I started Cycling 3 years back I came across this Video. Yoour post above reminded me of this..

  

 

Something to keep in mind:

Quote

The first law of thermodynamics, also known as Law of Conservation of Energy, states that energy can neither be created nor destroyed; energy can only be transferred or changed from one form to another. For example, turning on a light would seem to produce energy; however, it iselectrical energy that is converted.

In other words, if it takes 1Kwh to get the mass up, it will give 1Kwh back. Nothing More. There will probably be losses thought, through heat exchange  / water loss / friction / etc, so you probably won't get 1Kwh out. 

 

In other words, if you want to get 1Kwh out ( am using round figures as an example, do you need to do the math) you either need to get that energy from another source, or have it as spare energy. What I mean to say is, if you want to use this as a "battery backup" for evening loads, and you have 1Kwh spare PV power during the day, you could probably save about 5Kwh-6Kwh with the excess solar energy. But if you don't have power to spare, you would essentially use precious energy to generate energy.