electric.I have one that cost me nothing.. Just a little bartering...There are costs associated with that. It wouldn't be free then.You can use a motorized pump...
What is the source of fuel for the motor in the motorized pump?
Let me guess, you generate your own electricity using cow farts so the electricity does not cost you anything.
GREAT IDEA!!!!!! I support the HARVESTING of many many different forms of energy into BATTERIES----
set up on every acre of land--------babies----who engage in CONSTANT frenetic activity should be hooked
up to batteries (ie wired) ------ass holes can also be WIRED etc etc