Heavy Load Motor-Generator (Dynamotor) Questions
Heavy Load Motor-Generator (Dynamotor) Questions
(OP)
The motor-generator will be used to pull a load up a mountain side/steep incline on a rail system, the load is between 10 and 300 tonnes, its for a gravitational potential energy storage system. Excess electricity pulls the load up the incline, when there is demand for electricity the load is released driving the generator. Obviously a good gearing system is required.
Is this technically possible? How much do you estimate one would cost? What would be the device's efficiency?
Is this technically possible? How much do you estimate one would cost? What would be the device's efficiency?





RE: Heavy Load Motor-Generator (Dynamotor) Questions
Think how much mass of water a pumped hydro scheme stores - typically thousands of tonnes, many tens of thousands in the bigger ones.
How much power are you wanting to generate, and for how long?
----------------------------------
If we learn from our mistakes I'm getting a great education!
RE: Heavy Load Motor-Generator (Dynamotor) Questions
RE: Heavy Load Motor-Generator (Dynamotor) Questions
RE: Heavy Load Motor-Generator (Dynamotor) Questions
I have no idea of cost.
Not sure what you mean by efficiency, but I'd guess you could recover something like 70% of the energy used to move the mass up the hill.
As for the bigger picture, a quick calculation tells me that a 300 tonne block moving 500m vertically stores about 400kWh. What you propose doesn't sound large enough for a utility scale but it might work for small scale storage, say for storage of power from solar panels or a wind turbine.
RE: Heavy Load Motor-Generator (Dynamotor) Questions
Is this for solar or wind storage?
Keith Cress
kcress - http://www.flaminsystems.com
RE: Heavy Load Motor-Generator (Dynamotor) Questions
Not had much luck with manufacturers.
RE: Heavy Load Motor-Generator (Dynamotor) Questions
Be pretty cool really. Much better than battery storage too. An excellent idea in my view.
1kwhr = 3.6MJ
1 tonne x 1000kg/tonne x 1m x 9.8m/s2 = 9,800J
3.6MJ / 9,800J = 367m
You need to raise each tonne 367m per kwhr. A 100tonnes would need 3.67m. Ouch.
Keith Cress
kcress - http://www.flaminsystems.com
RE: Heavy Load Motor-Generator (Dynamotor) Questions
Keith - water as a storage medium works well on big stations because of the difficulty in suspending a three thousand tonne block over a hole over half a mile deep, which based on Lionel's figures is roughly what is needed to replicate the Dinorwig pumped storage station's capability.
----------------------------------
If we learn from our mistakes I'm getting a great education!
RE: Heavy Load Motor-Generator (Dynamotor) Questions
So, considering this is an islanded system, I'm thinking a 4 quadrant VFD with a custom build control system will be needed. The VFD must be able to synchronize with whatever line power is available and the control system will have to regulate the speed of the motor to match the output power with the system demand.
Most RE will more or less produce more output voltage when producing more power. So, it's possible the control for the weight could use the line voltage, running slower or uphill if the voltage is high and run faster downhill if the system voltage is low.
You'll need to first come up with a more detailed specification than lowering a 10 to 300 tonne block down a hill before you can get any answers on equipment. If you're looking for a turnkey solution then you'll likely need to employ an engineering firm, since I doubt any manufacturers will do this level of engineering.
Well, this is besides the issue of sorting out the control system so it doesn't fail and let the 300 tonne block go flying down the hill on it's rail tracks...
RE: Heavy Load Motor-Generator (Dynamotor) Questions
Sounds like a good plan to me Lionel! You could use a typical Otis Elevator safety for preventing an, um, embarrassing descent rate.
Keith Cress
kcress - http://www.flaminsystems.com