Chip manufacturers are constantly pushing to reduce power consumption to a minimum, but they still have to face the limitations that come with dealing with the world of electronics. In particular, the power consumed by a CPU is roughly proportional to its frequency and the square of its voltage, with a good portion of the consumed energy being dispersed as heat.
One promising solution could be to build circuits that use photons instead of electrons to store and elaborate data. This would drastically improve power consumption, because one photon is enough to both store a bit of information and activate a transistor. An all-optical computer could also reach much higher data transfer rates (think fiber optics).