Almost all sources of energy generate power by converting mechanical energy into electrical energy using appropriate transducers. Electromagnetic induction using magnets and coils as the transducers are the means employed in most cases. A transducer is a device that can convert energy from one form to another.
You can exploit energy from the wind using a wind turbine. When the wind blows, it causes the blades of the turbine to rotate and power an electricity generator. The generator is comprised of coils wound around magnets that move relative to the magnets cutting through the magnetic fields. Cutting across the magnetic field induces a current across the coils, leading to a regulator that stabilizes the generated electricity. The strength of the current induced depends on the intensity of the wind.
Hydroelectric plants use similar means of generating power to that of exploiting wind energy. The only difference is that, in this form of green energy, the force of moving water drives the turbines connected to the electricity generator. Just as in wind-energy generation, the turbines convert the mechanical energy caused by the moving water to electrical energy, then direct it elsewhere for use. Some of the sources of hydroelectric power include rivers, waves and tides in the sea.
Nuclear Energy is yet another source of sustainable energy. It also employs electromagnetism to generate electricity as well. Nuclear power plants harness heat energy generated by nuclear fission of radioactive elements to turn water into steam at high pressures. This pressured steam then drives large turbines that generate electricity in a similar fashion to the hydroelectric and wind turbines.