Alright so follow me on this.
Cats always land on their feet.
Buttered toast always lands butter side down.
So if we could strap buttered toast to the back of a cat what would happen?
As you can see the cat falls to the ground it begins to slow down, the cat must land on it's feet and the toast must land butter side down. This causes the initial rotation, as the buttered toast nears the ground the cat rotates to attempt to land feet first, followed by the buttered toast causing them to spin at an ever increasing rate.
Now if we were to stick this cat inside a power generating turbine we could power all our lights indefinitely.
As you can see this could be groundbreaking. There are some problems with this system.
1. Cats are evil by nature. Having been created as physical manifestations of Satan their piercing "I'm so cute" gaze can turn even the coldest heart.
2. Without some sort of assisted breaking this machine spins faster and faster until the turbine breaks apart and the cat implodes into a singularity of pure energy blasting light 100x brighter than the sun for 30 seconds. This can be useful in the final minutes of flowering but it's difficult to time these things out and not recommended.
3. Cats don't like spinning. Research has shown it is difficult to use the same cat twice, two lab technicians have be killed by a cat trying to escape.
4. Cats will lick the butter off the toast eventually. Current research is being done to see if cats can lick the butter at a linear rate, thereby keeping speed constant while providing a tasty treat for the cat.
If we can overcome these and any other possible unforeseen problems we will be well on our way to a golden age of cat powered cars, homes, plants and marijuana grow operations.