There were over 1,500 connections in Hamilton by 1923. Undergrounding began in 1926, when the 11 kV cable was extended from Peachgrove Rd to Seddon Rd sub-station. By 1928 the Council had 3,381 consumers and charges were down to 6d per kWh for lighting and 2d per kWh for power and heating. By 1935 4,458 were connected, with of line and lighting was down another penny. By 1950, the 11 kV rings in Hamilton East and Claudelands were finished. Soon afterwards mercury vapor street lighting was installed in London Street and Norton Rd. 33kV gas- and oil-filled cables were laid from 1960 and switched on in April 1974. By 1987 there were 12,247 connections, of line and charges down to 6.577c/kWh (about 13c in 2015 prices). In 2015 prices varied from 11.31 to 22.92 cents per kWh.