
Originally Posted by
watercooled
There is no 'extra power input' to be dissipated. Higher voltage results in them drawing less current - they are not linear devices, and nor does a higher voltage within spec reduce life. Properly-designed devices will be capable of dissipating spikes well above spec too. A modern computer power supply can operate worldwide and obviously won't draw twice as much when connected in the UK vs USA. In fact as I said earlier, they tend to be more efficient at higher voltages so draw less power overall.
Single-phase AC motors (of which there are very many types) would generally only be damaged if the voltage was high enough to break down winding insulation or start/run capacitors which are usually specified *way* above line voltage, amongst other things to protect against failures due to everyday voltage surges. In fact the windings would usually go through an insulation resistance test at roughly double the supply voltage, sometimes known as hi-pot or dielectric strength testing though they're not necessarily the same thing. Washing machines are different again as they're generally three phase motors fed from a variable frequency inverter drive.
If 5-10% over-voltage is destroying lamps, they're crap lamps, plain and simple. Voltage changes will not vary the brightness of properly regulated LED lamps, but may do so for the very cheap ones fed through resistor/capacitor droppers, however the difference still may not be as obvious as the fairly large difference seen with incandescents.