James Post

Very interesting and informative article. Thanks for the post.

Brad Hughes, my thoughts exactly!

Basically, we need an alternative STORAGE mechanism for storing electrical energy other than the chemical battery solutions we have had for years.
I know that torsional springs and twisted steel shafts can store a tremendous amount of energy. I was thinking, as you were, that one would use an electric motor to "windup" this Mechanical battery. Yes, there would be some loss of energy involved, but that is true of any physical process -- it's the second law of thermodynamics.

I have a trial version of software that supposedly uses Finite Element Modeling to predict the behavior of clock-like windup springs. It is limited because it is a trial version, but if it shows promise, I will investigate it further. Basically, the questions that I want to answer are (1) How much energy [KJoules] can this type of spring hold realistically and (2) what power are we talking about for such a windup motor to be used to generate mechanical energy back to electrical energy [KWatts]. Just want to get a sense of what is achievable.

For example Gasohol E10 (10% ethanol 90% gasoline by volume) has an Energy Density of 15.08 MJoules per gallon. So, a 10 gallon gas tank in an average automobile stores roughly 150.8 MJoules of energy. That's a lot of energy. Can any spring/shaft combination come close to that amount of Energy? That's what I'm interested in answering.

Just wanted to say that we are thinking of this the same way.
Don't know if it will come to anything, but wanted to give some validation.

Regards,

I was thinking that this concept could be used to build a wind-up motor (like that found in a Victrola) only on a large scale.
This could be used as a supplement to the battery in hybrid cars or all electric cars like the Telsa Model S.
Essentially, the same concept as a hybrid only using a wind-up motor instead of a gasoline engine.
The wind-up motor would turn an electrical generator that would feed into the fully charged battery.
As current is drawn from the battery by the induction motor, it would be replaced by current generated by the wind-up motor/generator.
This would extend the range of the electric car.

Yes, there would be energy loss in the windup process and I don't know how efficient it would be. But, that is true of anything.
More electrical energy is used to charge a battery than it can return. All machines and physical processes are less than 100% efficient.

I just thought that this is a mechanical (non-chemical) way of storing electrical energy. It would have the advantage of being "quickly charged" compared to the 10 hours the Telsa battery
takes.

My problem is, I am mechanical engineer with a masters degree so I like to do calculations. I'm trying to find/develop equations to calculate the potential mechanical energy that can be store by wind-up "clock type" springs. That way I can get an idea of how feasible it is in terms of size/weight/power... For example, the Tesla Model S battery is 85KW-hr. That's 306 MILLION Joules of energy or 290,032 BTUs. That is a lot of energy (enough to power a 12,000 BTU/hr air conditioner for nearly 24 hours), but gives me an idea of the energy storage requirements for a mid size car that preforms very well. The Telsa model S has a 400 hp induction motor and goes 0-60mph in 4.4 seconds.

I've had the idea of storing electrical energy using windup springs for years, but just never worked on it. It's nice to find a forum of like minded people.
Hope this makes some sense to you all.

I plan to post updates as I get closer to mathematical understanding of the windup motor problem.