HeliStudent
Here is the NOTAM - it appears to be lit at night
Q) EGTT/QOBCE/IV/M/AE/000/008/5129N00007W001
A) EGLW B) FROM: 13/01/07 17:00C) TO: 13/03/15 23:59
E) HIGH RISE JIB CRANE (LIT AT NIGHT) OPR WI 1NM 5129N 00007W, HGT
770FT AMSL (VAUXHALL, CENTRAL LONDON), OPS CTC
12-10-0429/AS 2.
From AIS site