Why can't I put 110 V appliances on 220 V outlets?
Circuits designed specifically for 110V will have lower impedence. Plugging these into a 220V supply will have higher current and thus higher power. Components will either burn up or explode.
Power is not &quot;required&quot; by devices. Power consumption is a result of the voltage input and impedence of the device. The impedence (\$Z\$) is generally independent of the voltage and power is $$P=\frac{V^2}{Z}.$$
Some devices, such as transformers and switching power supplies have components designed to function properly over a large range of input voltage.