does n't generate a lot of energy 
(ROOT (S (VP (VBZ does) (RB n't) (VP (VB generate) (NP (NP (DT a) (NN lot)) (PP (IN of) (NP (NN energy))))))))
(ROOT (S (VP (VBZ ) (RB ) (VP (VB ) (NP (NP (DT ) (NN )) (PP (IN ) (NP (NN ))))))))