John Lee Roberts, electrical engineer, was educated at St Marks College, London, and received his professional training at the English Electrical Construction Company. In 1896 he came to Durban as representative of that firm, to supervise the installation of the first electric lighting plant in the city. Upon the completion of this work, in October 1897, he was appointed as the first electrical engineer of the borough, a post he held until his retirement in December 1932. During these years the Durban Electricity Department expanded from four lights in the centre of town to serving over 20 000 consumers.
Roberts visited continental Europe, Britain and the United States in 1899 to study electric traction. Upon his return he advised the city council to take over the existing private telephone and tramway companies in the city and helped to adapt both to the city's requirements. In 1902 he supervised the conversion of the trams to electric traction and around this time supervised the installation of the municipal telephone system. He particularly encouraged the domestic use of electricity by holding electrical exhibitions and introducing the hire-purchase system for buying electrical appliances. In 1922 he proposed that Durban establish a municipal radio broadcasting station and under his guidance it was inaugurated in 1924.
In 1924, in addition to his post as borough electrical engineer, Roberts was appointed local manager of the Durban undertaking of the Electricity Supply Commission, a position he held until February 1937. In 1936, he attended the World Power Conference in the United States as an official South African delegate with Dr H.J. van der Bijl, chairman of the Electricity Supply Commission.
His lectures before the Durban Sanitary Association were published under the title Electricity in sanitation: Lectures delivered before the Durban Sanitary Association (1902). Later he wrote a pamphlet on Electricity as a by-product (with special reference to the sugar industry) (Durban, 1918, 11p). Two papers by him were published in the Transactions of the South African Institute of Electrical Engineers: 'Economics of electric transmission and feeder systems for urban electricity supply' (1925, Vol. 16(9), pp. 117-135) and 'A waste heat power station' (1927, Vol. 18(11), pp. 176-188). In 1932 he and H. Clark read a paper on the cost of generating and distributing electricity at the annual congress of the South African Association for the Advancement of Science.
Roberts was a member of the (British) Institution of Electrical Engineers; a member of the South African Institute of Electrical Engineers; and a foundation member of the Association of Municipal Electricity Undertakings of South Africa, serving as its president during 1924-1926. In 1902 he married Kate Blundell, with whom he had two sons and a daughter.