Notice I said "systems"
Let us take an hypothetical but potentially real world example.
There is a greenhouse on a small hill and below it is a stream. You need a small amount of water in the greenhouse but you have no power available to pump that water up to it.
"Hydraulic water rams are an inexpensive, creative way to pump water. These semi-efficient, self acting pumps use the force of water running down stream to pump water up an elevation: with six feet of drop, a hydraulic ram pump will lift water 100 feet up a hill."
OK, that gets us some water up the hill without using any power/energy/labor. Yes we are using the energy of the water flowing down the stream to do this, but it is "free" the water would have gone downhill anyway.
This greenhouse needs cooling in summer, what would it cost to run an air conditioner in there to "pump" out the heat as compared to using a solar chimney to create a draught and using the constantly flowing water we have from our water ram to cool the incoming air (swamp cooler)
Heating.
Do we use electricity to heat the greenhouse or do we use electricity to power a pump that moves heat from solar panels to a storage tank in daytime and then at night moves warm water to radiators within the greenhouse? just thinking about that one, if we took the water from the water ram output and put it through the solar panels then into the storage tank then out through the radiators we would not need any external power to heat the greenhouse at night.
This is an "ideal scenario" the objective was to keep a greenhouse coolish during the day and a bit warmer than ambient at night using no external power source except a stream and the sun.
Compare the costs of that against the costs of energy for pumping, heating and cooling. If it costs less then you are getting "Over Unity" as in you are getting more out of the system (in regards to energy usage/wastage ) than you are putting in.
Now the real world!!!
Where I am in spring and fall during the day you need misters and fans to keep a greenhouse below 90F and at night you need the heaters on as it is well below freezing at night.
Storing the day heat and releasing it at night using loads of black poly tubing and 1000gal storage tanks costs one hell of a lot less than heating and cooling directly.
So, can we have a new name for MOVING energy to a place where you need it (heating) or moving it away (cooling) using little or no "power" that does not scare away the under or over unity people?
My imaginary system uses no external "power" but it moves energy around.