two patents on six machines designed to convert gravity to mechanical energy.

[sm0ky2]

If you imagine something like the 'drinking bird' that was allowed to go 360 degrees
(Dip under water and back around)
With a gas right at its' phase change pressure
like butane
a flywheel to give it momentum
And the generator from a needlepoint
at the center of rotation
Geared to a very large gear, low rpm very high torque
Make up for the low rpm by having hundreds of magnets
around the perimeter

[NathanCoppedge]

This happens all of the time.

The downdraft energy tower works to some extent, based on cooling hot air to send hot air heated close to the ground upwards. There may be other things that work fairly well, but few if any of them have been patentable so far.

Please visit: https://emporium.quora.com/The-History-of-Perpetual-Motion-Machines for more ideas.

Added note: I am surprised there has not been more use made of the sponge or cloth absorbing water on a slightly angled plane concept, with the drip returning downwards on a ramp without the cloth.

[sm0ky2]

The capillary engine works in a similar manner


Water drawn upwards by capillary effect drips onto a waterwheel


a great many capillaries would produce an 'artificial tree' water pump
As seen in the redwoods - this effect can extend upwards at least 1000 feet