Janet,

You might want to look at the economics of a 2-speed motor, like these:
http://www.a1poolparts.com/-strse-Mo...Categories.bok

A 2-speed motor will move 1/2 the water on low for 1/6 the electricity.

I wouldn't bother with the electronic multi-speed motors. As far as I can tell, they do not save any more than then regular 2-speed . . . IF you have sized your pump correctly. And they do cost a LOT more.

However, you often won't find ANY multi-speed motors (2 speed or more) in local stocks, so if you want to go this way, you'll want to order parts BEFORE your motor finally dies.