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

 

[alphy]

I can provide some information on the efficiency of alternators and generators. Generally, the efficiency of an alternator or generator refers to the ratio of the electrical output power to the mechanical input power. This can vary depending on the type of alternator or generator and its size.

In the case of brushed alternators, which use brushes to transfer current to the rotating armature, the efficiency can range from 50 to 60%. This is because the brushes create friction and can cause energy loss. On the other hand, brushless alternators, which use electronic components for current transfer, can have efficiencies as high as 75%.

The efficiency of a generator or alternator can also depend on its size. Generally, larger generators tend to have higher efficiencies due to their improved design and construction. This is because larger generators have more space for insulation and better cooling systems, which can reduce energy loss and improve efficiency.

When it comes to power station generators, the efficiency can vary depending on the type of fuel used and the type of generator. For example, gas turbines and diesel generators can have efficiencies ranging from 35 to 40%, while steam turbines can have efficiencies of up to 60%.

In summary, the efficiency of alternators and generators can vary depending on their design, size, and type. However, larger generators tend to have higher efficiencies, and brushless alternators can have higher efficiencies compared to brushed alternators. It is also important to consider the type of fuel and generator used when discussing efficiency.