In the early 1900s London’s transport was starting to turn to electricity for its power. The early underground trains had been hauled by steam locomotives, but few people liked the clouds of steam and sooty smuts that plagued the station platforms and the need for ventilation meant that underground lines had to be built near to the surface. Using electric power meant that deeper lines could be constructed, beneath parts of the city where sub-surface lines were impossible to build. So as the underground (and the tram network) began to hook up to electricity, power stations were required, and one was built in Greenwich.
When the 1910 phase of building was completed, turbines – the latest generating technology – were installed in the new part of the building, and eventually the steam engines were removed and more turbines were installed. There are still turbines in the power station, and the equipment is kept in working order and occasionally run as the power station stands by as a back-up facility for the Underground.