Other activities include repairing, testing and maintaining power plants, providing engineering, procurement and construction services for power plants related products, assembling and manufacturing high voltage switchgears, coal mining and trading.

Operations are carried out in Malaysia, (except Sarawak), United Kingdom, Ireland, Turkey, Kuwait, Saudi Arabia, Pakistan, India, Cambodia, and Australia.

[5] The Lembaga Letrik Pusat (Central Electricity Board, CEB) was established and came into operation on 1 September 1949.

By the 1980s, the Board was supplying the whole peninsula with electricity, replacing the Perak River Hydro Electric Power company (PRHEP) and its subsidiary Kinta Electrical Distribution Co. Ltd (KED) in 1982, Penang Municipality in 1976, and areas supplied by Huttenbach Ltd in 1964, which included Alor Setar, Sungai Petani, Kulim, Lunas, Padang Serai, Telok Anson, Langkap, Tampin and Kuala Pilah.

[8] In 2021, Tenaga became part owner of the repowered Blyth Offshore Wind Farm in England.

[9] The TNB Group has a complete power supply system, including the National Grid which is energised at 132, 275 and 500 kilovolt (kV), with its tallest electricity pylon in Malaysia and Southeast Asia being the Kerinchi Pylon located near Menara Telekom, Kerinchi, Kuala Lumpur.