Adding cooling to a generator - would it be more efficient?

Thread Starter


Joined Oct 10, 2014
I was watching some video's on permanent magnet motors in one one the guy built his own and added cooling on the stator to keep the windings cooler. This is so the motor can draw more current. Less heat means less resistance so less energy is wasted as heat when the motor is being run, less energy consumed as resistance within the windings.

So I was thinking of this in opposite terms, if cooling could be applied to a generator. If the temp could be dropped significantly in the coils then the generator could output more current but it would still require more "force" to turn the generator. What I am curious about is how much energy is wasted by the added resistance of the increased current/heat.

If a large generator could be built with massive cooling, say with pure copper tubing instead of wire, with coolant running through the tubing (which make up the coils), would the generator be significantly more efficient?

I was thinking that this might be useful in hydroelectric generation but the problem comes with the conductivity of water but maybe the inside of the tubing could be coated with enamel/insulation the same as magnetic wire - or a non-conductive fluid could be used as the coolant instead of water - with a heat exchanger using the flowing water to remove excess heat.

So I know the generator would be capable of higher amperage but I'm wondering if the overall efficiency would be greatly increased by a setup such as this. Does anyone know what the numbers might be or if the efficiency is increased with size, like the larger the generator or more cooling capacity, the greater the efficiency gain?


Joined Jan 15, 2015
You may want to give Corrosion in the stator cooling system of power generators is a primary source of maintenance costs and plant downtime a read. I have worked with cooling systems for some interesting motor systems and getting into the water chemistry is a science unto itself. What you suggest is nothing really new and has been done. The problem is not the conductivity of the water but more a matter of what we called the water chemistry. You may also want to note the conductivity of various water grades such as Grades A B and C Water.



Joined Sep 7, 2010
Also this cooling will require energy input ...

A better idea might be to use silver instead of copper for the conductors . Silver is 5.6% more conductive than copper ...

Currently there are around 530,000 tonnes of silver , mostly in the form of ingots , being held by country's central banks vaults , costing money to guard .... instead of lying around doing nothing this could be made into windings for hydro generators etc ... no security needed ,