Alternator , generator efficiency

[Mr.Bomzh]

Hi I've been looking in google although I can't find a definitive answer, what are the usual efficiency range for alternators, some talk about brushed ones in the range of 50 to 60 % , brushelss some say go as highas 75%, maybe some of you folks know from your experience what are the typical efficiency of a power station generator for example, does the efficiency increase with size?

 

[russ_watters]

It does increase with size and power stations run on the order of 95%.

 

[Alkemist]

Hi I've been looking in google although I can't find a definitive answer, what are the usual efficiency range for alternators, some talk about brushed ones in the range of 50 to 60 % , brushelss some say go as highas 75%, maybe some of you folks know from your experience what are the typical efficiency of a power station generator for example, does the efficiency increase with size?

You may want to read this thread https://www.physicsforums.com/showthread.php?t=738434&page=4
It doesn't give the complete answer, but discuss about generator efficiency. Generators are never high efficient machines.

 

[jim hardy]

I believe you'll find power plant alternators can beat 98%.
They do tricks like use compressed hydrogen for cooling because hydrogen being less dense than air takes less power to pump .
Utility would prefer to sell that energy as electricity than dump it as heat.
Here's a Toshiba link offering 99%.
http://www3.toshiba.co.jp/power/english/thermal/products/generators/hydrogen.htm

In a car alternator the only incentive for efficiency is there's less heat to get rid of, so efficiency let's you reduce heat transfer area which means a more compact unit.
With today's smaller engines and fuel economy mandates there's probably increased attention to efficiency - but in my day everybody had 400 cubic inches and a half acre engine compartment..
http://www.moparmusclemagazine.com/...rysler_300d_well_traveled_brute/photo_01.html