Mumbai saw electric lighting for the first time in 1882. The place was the Crawford Market. The following year the Municipality entered into an agreement with the Eastern Electric Light and Power Company. Under the agreement, the Company was to provide electric lighting in the Crawford Market and on some of the roads. But the Company went into liquidation the following year, and the Market reverted to gas lighting. Thus ended the first scheme to provide electric lighting in the city.
Another scheme was taken up for consideration in 1891; and in 1894 the Municipality sanctioned funds for installing a plant to generate electricity. The current was to be supplied to the Municipal offices and Crawford Market. It was, and the two places were fitted up with electric lights. But by 1906, with the wear and tear of all those years, the machinery at the plant was in a bad way. The current would stop off and on. So, once again, Crawford Market went back to gas lighting. The Municipal offices, however, arranged to get the electricity it needed from the newly established "Bombay Electric Supply & Tramways Company".
This Company was originally established in England, as a subsidiary of the British Electric Traction Company, which had been trying since 1903 to bring electricity to Mumbai. The Brush Electrical Engineering Company was its agent. It applied to the Municipality and the Government of Bombay in 1904 for a license to supply electricity to the city. With the municipality approving the Company’s schedule of rates, the Government issued the necessary license : "The Bombay Electric License, 1905. When the Bombay Electric Supply & Tramways Company came into being, it entered into a contract with the original licensee to take over the right of supplying electricity to the city.
The Bombay Electric Supply & Tramways Company (B.E.S.T.) set up a generating station at Wadi Bunder in November 1905 to provide power for the tramway. The capacity of the station was 4,300 kws. The needs of the city and of the tramway in respect of electric power were bound to grow. At a rough estimate the full capacity of the Wadi Bunder plant was not going to be adequate beyond 1908. The plant could not be expanded much either. So it was decided to set up another generating station, one with a higher capacity, near Mazgaon (Kussara). It started functioning in 1912. The pace at which the demand for electricity grew can be gauged from the fact that within three years the Wadi Bunder Station proved to be inadequate. The tram service had been expanding, and more and more power was needed for the industrial and commercial establishments, as well as for domestic purposes.
Bombay Electric Supply & Tramways Company started supplying electricity to the city in 1905. Until 1926, the Company had been generating its own electricity for distribution to its consumers. Later, the Tata Electric Companies started supplying electricity to the BEST. The Tata Electric Companies (The Andhra Valley Power Supply Co. The Tata Power Supply Co., The Tata Hydroelectric Power Supply Co.) generated electricity from their reservoirs at Bhira, Bhivpuri and Khopoli in the Western Ghats. A major portion of it was transmitted through 110,000 Volts overhead lines to their Receiving Stations at Dharavi and Parel. In these Receiving Stations the voltage used to be transformed to 22,000 and 6,600 volts for ease of distribution. The Tata Electric Companies provided, through their cables, electricity at requisite voltage to the industries and mills, the Railways, the Bombay Suburban Electric Supply Company and the BEST.
In 1947, when the Company was taken over by the Municipal Corporation, the Undertaking was buying electricity from Tatas at nine receiving points known as : Kussara, Mahim, Kingsway, Jamnadas, Suparibag, Lalbaug, Esplanade, Palton and Backbay. At all these points, except Kussara, Kingsway and Mahim, the supply was received at 6,600 Volts. The supply was received at 22,000 Volts and transformed through Tatas’ transformers to 5,500 Volts at Kussara and to 6,600 Volts at Kingsway and Mahim. From these receiving points the cable network carried power to 247 Substations situated in different areas of the city. With the help of transformers at these substations, the voltage was further transformed to 400/230 Volts, suitable for use in the factory, shop and home. It was made available to the consumers through a low voltage distribution network and service cables to individual buildings. The major portion of electricity distributed was at Alternating Current (A.C.). But, in some areas of South Bombay, particularly Fort, Kalbadevi and Girgaum, Direct Current (D.C.) was supplied at a voltage of 460/230 Volts. To convert it into D.C., Rotary Converters were operated at Pathakwadi, Telwadi, Apollo and Palton Road Substations and Mercury Arc Rectifiers were used at Phirozshah Mehta Road substation.