That only applies if they are un-overclocked. Once overclocked you are outside of the Thermal Design Power.
A quick comparison of the FX-9XXX series and their 200W TDP tells you what you have to do to get the AMD chips to run flat out. Intel is similar, the very high speeds are reached at draws as much as 160W (more for the big CPUs on LGA2011) when the TDP of Haswell is 84W, and Ivy bridge is 77W.
Not a huge factor to the enthusiast except that in general high-end overclocking AMD boards need a little more oomph to reach high clocks, but since Intel limits overclocking to only the performance boards, it is sort of a wash in terms of costs.
For the enterprise, Intel chips save on electricity in the long run (better battery life on laptops too)