The two conformations differ in energy: the staggered conformation is 12.6 kJ/mol (3.0 kcal/mol) lower in energy (more stable) than the eclipsed conformation (the least stable).
ðə tˈuː kɑːnfoːɹmˈeɪʃənz dˈɪfɚɹ ɪn ˈɛnɚdʒi: ðə stˈæɡɚd kɑːnfoːɹmˈeɪʃən ɪz twˈɛlv.sˈɪks kˈeɪ dʒˈeɪ slˈæʃ mˈɑːl θɹˈiː.zˈiəɹoʊ kˈeɪkˈæl slˈæʃ mˈɑːl lˈoʊɚɹ ɪn ˈɛnɚdʒi mˈoːɹ stˈeɪbəl ðɐn ðɪ ɪklˈɪpst kɑːnfoːɹmˈeɪʃən ðə lˈiːst stˈeɪbəl.