Overclocking.guide delivers all sorts of tuning guides and articles that will help you push your hardware higher. Whether you need an introduction to the BIOS settings of a specific motherboard or you need a detailed guide on how to install a power board on your graphics card, you can find it at Overclocking.guide.
In the most recent article published by Der8auer we find a fairly simple breakdown of Intel Skylake scaling when overclocking, both in terms of power consumption and voltage scaling. The article includes visualized graphs to help you understand the scaling better. Der8auer is using the following components: Core i7 6700K, ASUS Maximus VIII Hero, LEPA G1600 PSU, 2x 4GB HyperX Predator DDR4-3300C16, and Noctua NH-D15 (1 Fan, 2 Watt).
The to-long-didn't-read (but you really should) is as follows. For an increase to 4700 MHz you will need around +250 to +300mV (1.4V) depending on the CPU silicon quality. The power consumption after overclock with increased voltage levels will possibly be over 200W under load, coming from 143W at default settings. In Idle the power consumption increases about 10%.
For more details and information, check out the article at overclocking.guide.