( ( ( The ( ( heated up ) water ) ) ( upon ( de-pressurization ( at ( the surface ) ) ) ) ) ( ( turns ( to ( steam ( which ( ( is then ) ( used ( to ( ( power ( steam turbines ) ) ( for ( electricity generation ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (ADJP (JJ heated) (PRT (RP up))) (NN water)) (PP (IN upon) (NP (NP (NN de-pressurization)) (PP (IN at) (NP (DT the) (NN surface)))))) (VP (VBZ turns) (PP (TO to) (NP (NP (NN steam)) (SBAR (WHNP (WDT which)) (S (VP (VBZ is) (ADVP (RB then)) (VP (VBN used) (PP (TO to) (NP (NP (NN power) (NN steam) (NNS turbines)) (PP (IN for) (NP (NN electricity) (NN generation)))))))))))) (. .)))
The heated up water upon de-pressurization at the surface turns to steam which is then used to power steam turbines for electricity generation.
(ROOT (S (NP (DT This) (NN heat)) (VP (VBZ is) (VP (VBN used) (S (VP (TO to) (VP (VB convert) (NP (NN water)) (PP (IN into) (NP (NP (NN steam)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBZ is) (ADVP (RB then)) (VP (VBN used) (S (VP (TO to) (VP (VB turn) (NP (DT a) (NN turbine))))))))))) (, ,) (S (ADVP (RB thus)) (VP (VBG generating) (NP (JJ electrical) (NN power))))))))) (. .)))