heating with renderings

[mraw]

I always thought of it as a real cool thing- instead of heating your rooms, just rendering some cool stuff.
Recently my power meter was swapped with a new digital one and I started to be curious how much electricity I actually burn with my render-test.
I got:
I-7-5960X running at 4.0Ghz-PSU corsair rm650i
I-7-3770k running at 3,8(?)Ghz- PSU bequiet  BQT L7 350W
2 nodes double E5-2670(more or less the Juraj-buil) with seasonic g series 650 W

eyeballed 5-6 days 24/7 rendering burnt 175kWh- yes, it was cozy and warm.... :)

Do you guys consider this as 'normal'-numbers?
I read something about the PSU being most efficient at 50% load. My PSUs are obviously too weak, how much impact would a better efficiency have?
I'm really concerned because this 6 days rendering wasn't paid- just tests...

[burnin]

Seems quite reasonable consumption on 4 machines running  ~130 hours.

Note
In few EU countries (Netherlands, Germany, France...) few companies are already getting on with using smart & efficient solutions. 
Check eRadiator, Nerdalize, Eneco, Qarnot Computing (presented in 2015 on Blender Conference)...

For example:

Fight against oil&gas giants continues...
 

[mraw]

Thanks for the links- really interesting approach. Hopefully I can get some render jobs this winter... and save the heating! ;)