|How can you run a clock off of a potato?
The classic technique is to insert two dissimilar metal strips into the potato in order to build a simple battery. You can then run an electronic clock with the power provided by that battery. But the energy in that battery is coming from chemical reactions of the metals and not really from the potato. If you really want to use a potato as the power source for a clock, you should dry the potato out and burn it. You can use the heat of the fire to run a steam engine or to generate electricity.