For connecting of power supply voltage the flexible ribbon cable is used (2). (e-ink-reader.ru)
This variability is monitored and compensated in the same way utilities monitor demand changes each day, so there are not any actual changes in power supply for the end users. (windustry.org)
To destroy the cheapest and most reliable power supplies in the world in less than 20 years takes effort, but it can be done. (stopthesethings.com)