Appropriate High Tech

Solar ice maker

Click here for details

Evaporative air conditioning.

This works well only in hot dry climates where the latent heat of evaporation cools the incoming air (basically an evaporative system draws outside air over a 'wet towel' - the water evaporates from the towel and cools the air). Now a lot of work has been done on solar regenerated dessicant (like silica gel) which absorbs moisture from the incoming air making evaporative cooling efficient even in Nica type hot + humid climates.

Click here for a schematic.

These systems are at least 80% more efficient than conventional refrigerant based air conditioners.

DC motors

A DC motor is three times more efficient than an AC one.

Think about running DC lines round your house as well as 110/220 AC - no point in running fans, lights and many switch mode AC items off an inverter when they will run straight off batteries