The hotter it gets the better it works

It almost sounds like a contradiction, but solar-powered air conditioning makes use of an absorption chiller to convert heat into a thermal reaction that cools water pipes that in turn are used to cool airflow.
The system still uses energy for pumping the water, running the fans, and keeping rooftop mirrors aimed at the sun, but it's a step in the right direction.
Another similar rooftop mirror-based system is being developed at Southern California Gas Co. and it's parent company, Sempra. Both systems are experimental, and both make use of an absorption chiller to convert hot water to cold water.
Sempra Energy has a strong record of pioneering solar energy projects.

Tags: solar, central heating and air, heat pumps