Self-powering Turbines Possible?

[iGuest 3]

I've been thinking alot about alternative energy recently, and I was wondering, is it possible to get energy from a turbine, then use some of the energy to power the turbine? Does a turbine require the same amount of energy to power it as it produces, or is there any remaining? If this did work, it would produce less energy, but it would pretty much be free energy. All you'd have to do would be to start the turbine off, and let it keep going.

[jimmy89 0]

Looking at it simply, I think it might work. Imagine, you have a water turbine, water passes through the turbine, spinning it and creating electricity. This electricity powers a pump which would take the water back to the top to start again. Any excess electricity can be passed onto the electrical grid. Problem is that you must get the pump started in the first place (so you are going to need an external power source while the turbine gets up to speed) and also that one turbine may not generate enough electricity to power a pump and have excess to send to the grid!Still, I think its a good idea - but i'm sure it has been carefully examined before now!

[iGuest 3]

Or, you could have two turbines, and they each power eachother! Then you'd get more energy.Another cool idea would be clockwork energy. You'd just have to get someone to wind it up every now and then!

[toby 0]

They'd produce heat and noise till they slow down.That requires regular new energy, not different from filling your car up with petrol.

[tansqrx 0]

You are on the hunt for the age old myth of the perpetual motion machine. The bottom line is it does not exist. https://en.wikipedia.org/wiki/Perpetual_motion. It has been tried so many times that the US patent office will flatly refuse any application that is a perpetual motion machine.

 

The one thing that most people miss in this argument is efficiency. In other words, in the real world there is no such thing as 100% efficiency or perfect transfer of work (power) from one place to another. Take the turbine example. As the turbine is spinning you also have friction in the bearings, wind drag, and heat produced. All of this equals energy being lost in the system and a dropped efficiency. Even if the system is of 99%+ efficiency, that 1% will eventually bring the whole system to a stop.

[Mordent 0]

You are on the hunt for the age old myth of the perpetual motion machine. The bottom line is it does not exist. https://en.wikipedia.org/wiki/Perpetual_motion. It has been tried so many times that the US patent office will flatly refuse any application that is a perpetual motion machine.

 

The one thing that most people miss in this argument is efficiency. In other words, in the real world there is no such thing as 100% efficiency or perfect transfer of work (power) from one place to another. Take the turbine example. As the turbine is spinning you also have friction in the bearings, wind drag, and heat produced. All of this equals energy being lost in the system and a dropped efficiency. Even if the system is of 99%+ efficiency, that 1% will eventually bring the whole system to a stop.

Yup, that pretty much sums it up. The turbine system you talked about converts gravitational potential energy (the water being higher) to kinetic energy (the water falling and turning the turbine) to electical energy. Assuming that perpetual motion was possible (namely no friction and so on), you'd have no energy left to use at the end. As soon as you start tapping energy from it then it can't shift as much water back to the top to give it more energy, and so on.

 

One idea that has left me pondering is magnetism, however. If you attached magnets to a turbine such that they span as the turbine did, and had opposing pole magnets on opposite sides (so effectively you're spinning one large magnet), could you use that to, say, push a metal object up a tube against another turbine, and when the poles attracted it instead of pushing it away cause it to drop, generating more energy? As the motion wouldn't be directly opposing the motion of the first turbine (perhaps creating a little more friction as the axle is marginally tilted) could you use the same source to generate more energy?