jfcrn wrote:
I have a large chest freezer which is mostly empty. If I fill it with ice
(bags or gallon jugs of frozen water) will it use less electricity? It is
about 3 years old.

No. And manual-defrost chest freezers tend to be very efficient, using
half as much electricity as modern frostless refrigerator-freezers.
It's possible your freezer costs only $25 a year to run. Consider
filling it with milk when its on sale, taking care to remove at least
1/2 cup per gallon and purging the air to allow the containers to
expand as the water turns to ice.