Power Reduction in Air Conditioning

The best solutions don't involve the machinery, but the conditioned space - better insulation, window shades, and even green roofs would all help more than wringing an extra little bit out of the air conditioning plant.

However, I have seen neat innovations like submerging the condenser coils in the moisture drip tray to improve heat dissipation. Using a more efficient compressor motor would help, although in the U.S., those motors are about as efficient as an induction motor in that frame size can get. Doing better would require going to a synchronous motor technology, e.g., brushless DC, at significantly higher cost.

If i may expand the question a bit: Why does it always appear that during heating season the desired temperature is 5C or more higher than that desired during cooling season? If we could return folks to the expectation that it might be warm during summer, a great deal could be saved.

You might consider using an air conditioner designed for liquid cooling of the compressor. Drill a well and immerse a heat exchanger loop to couple to the compressor jacket. A very small additional circulation pump would be required. The earth makes a pretty good heatsink. DickL

The other replys to your post had some great ideas! Here are a few more:

Evaporatively Cooled Condensor - http://www.freus.com/

Advanced Evaporative Cooling -

Breezair (single stage) - http://www.breezair.com.au/

Oasys (two stage) - http://www.oasysairconditioner.com/

As a previous person noted there are ways to reduce, even eliminate, the need for compressor-based cooling all together. That's the smartest and usually the most cost-effective approach.

"An ounce of prevention is worth a pound of cure"

or

"An ounce of conservation is worth a pound of generation"