The Ministry of Environment, Forest and Climate Change (MoEF&CC) has revised India’s 2015 emission norms for thermal power plants that asked for mandatory installation of flue gas desulphurisation (FGD) systems.

The decision is likely to benefit about 79 per cent of the thermal plants of India. Industry experts asserted that new norms are likely to reduce power generation cost of thermal power plants by 25 to 30 paisa per kilowatt hour (Kwh), benefitting consumers.

After the revision FGDs will now be mandatory only for coal-fired based plants within 10 kms of cities with population of over 1 million, or plants in critically polluted or non-attainment areas or plants using high-sulphur imported coal. FGD is a system that removes sulphur dioxide (SO₂) from the smoke released by coal-fired power plants. Experts say while FGD is effective in high-sulphur conditions, the system is expensive, water-intensive and adds carbon dioxide emissions during installation and operation.

It is useful where high sulphur coal are used for plants, or where there is high ambient sulphur dioxide levels or dense urban proximity. The decision of the government follows independent assessment by three Indian research institutes – reportedly IIT Delhi, CSIR-NEERI and National Institute of Advanced Studies (NIAS) — who noted that even in areas without FGDs, ambient sulphur dioxide levels are well within national standards.

Additionally, full-scale retrofitting of FGDs are projected to increase carbon dioxide emissions, largely due to added limestone mining and auxiliary energy use. Environmentalists however argue that such relaxation risks delaying clean air goals. But government sources say that the new framework targets pollution where it matters most. Developing economy like India who still rely on over 80 per cent of its power demand on thermal plants, it serves a practical template. The new guideline is aligned to best global practices, even the US, the EU, and China have moved to targeted FGD deployment, not blanket mandates.