How Efficient Are Linear Generators Compared to Radial Generators?

[cgaday]

I have been having difficulty finding information regarding Linear Generators, maybe they have not been used enough and are begininning to be sought after more for renewable energy production.

Back to the title, does anyone know approximately the efficiency of a linear generator, or at least in comparrison to a radial electrical generator.

I have also been trying to find formulas relating to cycles/sec for the linear generator in relation to the length of stroke back and forth which it goes through.

Thanks.

 

[anorlunda]

There is no intrinsic reason why an infinitely long linear generator has efficiency different than a rotating one. Think of https://en.wikipedia.org/wiki/Linear_motor run as a generator.

However, reciprocating linear motion is more complicated. Efficiency would depend on the duty cycle. What fraction of the time is it moving full speed in one direction as opposed to accelerating, decelerating, sitting still.

I suspect that most sources of linear reciprocating mechanical power, use a mechanism to convert the motion to rotary before running a generator.