London Electric Supply Corporation
of 25A Cockspur Street, London, SW.
1885 Sir Coutts Lindsay installed electricity at his Grosvenor Gallery; as a result of demand from its neighbours an extensive system was installed which became London's first commercial electric power supplier.
By 1887 the London Electric Supply Corporation had been established by Sir Coutts Lindsay and his brother, Lord Wantage.
1887 From experience of his work at the Grosvenor Gallery, the London Electric Supply Corporation (LESCo) engaged Sebastian Ziani de Ferranti to design their power station at Deptford. He designed the building, the generating plant and the distribution system.
1888 The Corporation, of 79 Grosvenor St W., advertised the supply of electric current priced at 7 1/4 d per Board of Trade unit.
1889 One of the dynamos had blown up during the visit by the Board of Trade inspector conducting the enquiry into the future supply of electricity for lighting in London.
1891 On completion, the Deptford Generating Station was the first truly modern power station, supplying high-voltage (10kV) A.C. power that was then stepped down to 2.5kV at sub-stations and further stepped down to 50 or 100V for consumer use on each street. This basic system remains in use today around the world. Ferranti's contract at Deptford was not renewed; Ferranti left LESCo.
1891 February. Supply of current from Deptford began; this was via the step-down sub-station at Grosvenor Station.
1891 The company would be using Mr Ferranti's system which was different from the accepted forms of electricity distribution but in the interim the company had been distributing electricity using the system developed for the Grosvenor Station; that station was due to be vacated in 1890 but the fire at the station brought an early end to its use. The company had laid mains at great expense from Deptford to the Grosvenor Station and had tested the supply of electricity from Deptford
The company dispensed with Mr Ferranti's services - unfortunately for him there were no other British customers for his type of equipment.
1900 Mr P. W. D'Alton resigned as chief engineer. Mr G. W. Partridge succeeded him, and Mr C. E. Barley, late of Kensington and Knightsbridge Co, was to take special charge of the Deptford station as superintending engineer.
1912 A correspondent to The Times identified the company's Deptford station as one of 6 which should be considered for bulk supply in an integrated London network; it generated 1 phase 83Hz and 3 phase 25Hz 10kV with AC distribution.
1913 Six London companies placed a large advert about potential uses of electricity in the home and office - in the drawing room, in the dining room, in the bedroom, for cooking and for vacuum cleaning
1914 Supply electricity at pressures of 105 or 210 volts (alternating) and at 230 and 460 volts (continuous). 
1920 One of 9 London electricity supply companies who formed London Electricity Joint Committee (1920) in opposition to the schemes proposed by the Electricity Commissioners for London
1933 Ferranti's single phase 10kV line was finally taken out of service
Sources of Information
- Wikipedia 
- The Times, Apr 03, 1888
- The Times May 03, 1889
- Details and illustrations are in The Engineer of 5th April 1889
- The Times, Feb 18, 1891
- The Times, Mar 16, 1891
- The Engineer 1900/02/23 p 214
- The Times Jun 12, 1912
- The Times, Dec 01, 1913
- 1914 Whitakers Red Book
- The Times, Nov 26, 1926
- The Times, Mar 02, 1938
- The Times Dec 21, 1933
- The Times, 10 March 1948