timestamp (dd/mm/yyyy hh:mm:ss), energy (Wh)
17/06/2015 10:00:00,-672
17/06/2015 10:30:00,-93
17/06/2015 11:00:00,-654
17/06/2015 11:30:00,-717
17/06/2015 12:00:00,-1282
17/06/2015 12:30:00,-2128
17/06/2015 13:00:00,-1816
17/06/2015 13:30:00,-3225
17/06/2015 14:00:00,-1337
19/06/2015 12:00:00,0
19/06/2015 13:00:00,0