Even light bulbs have an energy rating, and this one is B-rated. The socket on this bulb is a so-called GZ6.35 socket.
From Amazon
Osram Lightbulbs 64634 HLX EFR 150 W, 15 V, GZ6.35PT, 20 x 1 cm, A4516140013
The product is available from £8.46 at international stores.