Tenaga Nasional Bhd (TNB) generates, transmits and distributes electricity. It develops, operates and maintains a portfolio of power generating units. The company produces electricity using crude oil, natural gas, hydro, coal and gas sources. TNB serves approximately 10.6 million customers in Peninsular Malaysia, Sabah and the Federal Territory of Labuan. It develops, operates and maintains a portfolio of power generating units. The company also provides operation and maintenance services to six independent power producers. As of December 31, 2022, it had combined generation capacity of 16,734.9 MW under equity, with coal accounting for 41.8%, followed by gas with 34.4%, hydro with 17.8%, renewables with 4.6%, oil with 1.3%, and mini hydro with 0.1%. The company transmits and distributes power from its generation units and IPPs in the country through a network of electricity lines, substations, and transformers. As of December 31, 2022, it had 97,421 primary and secondary substations, 798,626.59 circuit kilometers (c/km) of transmission and distribution lines, and 105,952 primary and secondary transformers. It supplies electricity to industrial, commercial, residential and other customers including mining, street lighting, agriculture, regenerator and free units. In FY2022, TNB sold 125,234.2 GWh of electricity. In FY2022, TNB produced a total of 105,273.8 GWh of electricity, with 88,343.2 GWh from coal and gas sources, and 9,167.8 GWh from renewable energy sources. In FY2022, the company's capital expenditure stood at MYR8,853.2 million, which grew 4.7% YoY. The company has ownership in energy-related assets across Turkey, Saudi Arabia, Pakistan, India, and the UK. It also has interests in district cooling facilities in the UAE; and also in the supply of spare parts, and provision of operation and maintenance services for power plant equipment in Kuwait and Pakistan.

TNB’s R&D efforts focus on new technologies, which can assist in climate change mitigation. It focuses on the optimization of chemical-based post combustion carbon capture process to reduce the energy requirement of CCU. In line with this approach, the company has completed five projects with its chemical-based R&D facilities. It also completed seven projects using the direct carbon utilization from flue gas emission through microalgae photosynthesis process, producing biomass as a by-product. In FY2022, TNB spent MYR76.4 million on R&D, which as a percentage of revenue, stood at 0.15% of its revenue and grew 11.9% YoY. The company holds two patents and numerous publications in relation to its completed projects.