Energy Efficient PSU

[reach4thelasers]

I'm building a new rig and I'm looking for a good mid-range energy efficient Power Supply Unit.

I'd like a PSU that reduces its energy consumption in line with demand in order to keep my electricity bill down. Does such a feature exist in a PSU? Can anyone recommend me a good, quiet power saving CPU?

 

[SupermotoMX]

look for things like 80 + gold / bronze rated, i think there is also some 90+ ones kicking about

 

[Surveyor]

I'd like a PSU that reduces its energy consumption in line with demand in order to keep my electricity bill down. Does such a feature exist in a PSU?

All PSU's do that.

They only draw as much power from the mains as is required by the components at the time.

There's information on the efficiency rating of PSU's here.

If you want recommendations on a specific PSU then please list the full hardware specification of the PC.