The first public power station was put into service in 1882 in London
(Holborn). Soon a number of other public supplies for electricity followed
in other developed countries. The early systems produced direct ccurrent at
low-voltage, but their service was limited to highly localized areas and were
used mainly for electric lighting. The limitations of d.c. transmission at lowvoltage
became readily apparent. By 1890 the art in the development of an a.c.
generator and transformer had been perfected to the point when a.c. supply
was becoming common, displacing the earlier d.c. system. The first major
a.c. power station was commissioned in 1890 at Deptford, supplying power
to central London over a distance of 28 miles at 10 000 V. From the earliest
‘electricity’ days it was realized that to make full use of economic generation
the transmission network must be tailored to production with increased
interconnection for pooling of generation in an integrated system. In addition,
the potential development of hydroelectric power and the need to carry that
power over long distances to the centres of consumption were recognized.