( ( This ( mechanical energy ) ) ( ( ( is then ) ( converted ( into ( ( ( electrical energy ) , ) ( that ( ( is , ) ( ( ( the ( kinetic energy ) ) ( of electrons ) ) ( ( ( moving ( through wires ) ) , ) ( by ( electric generators ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT This) (JJ mechanical) (NN energy)) (VP (VBZ is) (ADVP (RB then)) (VP (VBN converted) (PP (IN into) (NP (NP (JJ electrical) (NN energy)) (, ,) (SBAR (WHNP (WDT that)) (S (VP (VBZ is) (, ,) (S (NP (NP (DT the) (JJ kinetic) (NN energy)) (PP (IN of) (NP (NNS electrons)))) (VP (VBG moving) (PP (IN through) (NP (NNS wires))) (, ,) (PP (IN by) (NP (JJ electric) (NNS generators)))))))))))) (. .)))
This mechanical energy is then converted into electrical energy, that is, the kinetic energy of electrons moving through wires, by electric generators.
(ROOT (S (NP (JJ Moving) (NNS electrons)) (VP (VBP have) (NP (NP (DT a) (NN form)) (PP (IN of) (NP (NP (JJ kinetic) (NN energy)) (VP (VBN called) (NP (JJ electrical) (NN energy))))))) (. .)))