Renewable Energy from Gravity?

Ahh….no, despite the contents of this ludicrous article.

There is no energy in gravity.  Gravity is a force that is a function of the mass of two objects, say a brick and the Earth.

Force and energy are not the  same thing, though they are related.  Energy is force exerted over a distance.  If you lift a brick off the ground, you will have expended some of the chemical energy in your muscles, but the brick will now have the same amount of energy, which we call “potential energy.”  If you release that brick, it will hit the ground with that same amount of energy, which we call “kinetic energy.”

Energy is released when things fall due to the force of gravity; this is why we can generate electricity from hydrokinetics.  But energy is required to get that water uphill in the first place; this comes generally from the sun, which evaporates water at low elevations, some of which finds its way to higher elevations and then condenses back to a liquid as rain.