( ( Comparing ( ( equal amounts ) ( of energy ) ) ) ( , ( hydrogen ( ( ( ( is currently ) ( ( ( four times ) ( more expensive ) ) ( than ( traditional fuel ) ) ) ) ( if ( ( ( ( generated ( from ( fossil fuels ) ) ) , ) and ) ( ( ( 12 times ) ( more expensive ) ) ( if ( generated ( using ( solar ( or ( wind energy ) ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (S (VP (VBG Comparing) (NP (NP (JJ equal) (NNS amounts)) (PP (IN of) (NP (NN energy)))))) (, ,) (NP (NN hydrogen)) (VP (VBZ is) (ADVP (RB currently)) (ADJP (ADJP (NP (CD four) (NNS times)) (RBR more) (JJ expensive)) (PP (IN than) (NP (JJ traditional) (NN fuel)))) (SBAR (IN if) (S (S (VP (VBN generated) (PP (IN from) (NP (JJ fossil) (NNS fuels))))) (, ,) (CC and) (S (ADJP (ADJP (NP (CD 12) (NNS times)) (RBR more) (JJ expensive)) (SBAR (IN if) (S (VP (VBD generated) (S (VP (VBG using) (NP (JJ solar) (CC or) (NN wind) (NN energy)))))))))))) (. .)))
Comparing equal amounts of energy, hydrogen is currently four times more expensive than traditional fuel if generated from fossil fuels, and 12 times more expensive if generated using solar or wind energy.
(ROOT (S (NP (NP (NNP Solar)) (CC and) (NP (NN wind))) (VP (VBP are) (ADVP (RB still)) (ADJP (JJ expensive)) (PP (VBN compared) (PP (TO to) (NP (JJ fossil) (NNS fuels))))) (. .)))