Researchers urge stricter policies, financial incentives, and gas or solar alternatives to curb DG set emissions worsening city’s already fragile air quality
Bengaluru Urban has been identified as one of the six worst-affected cities in India for particulate matter (PM2.5) emissions from diesel generator (DG) sets. A pan-India study conducted by the Centre for Study of Science, Technology and Policy (CSTEP) highlights the alarming impact of DG-driven pollution on human health and the environment.
The study, Switch on, Smoke off: Reducing Emissions from Diesel Generator Sets, lists Bengaluru Urban, Mumbai, Patna, Gautam Buddha Nagar (Noida), and North 24 Parganas in West Bengal as high-emission districts. In 2022, nearly 14.7 lakh DG sets were operational across India, contributing 42 Gg of PM2.5, 23 Gg of black carbon, and 877 Gg of nitrogen oxides (NOx).
Researchers caution that the DG market in India is expected to grow at a compound annual growth rate (CAGR) of 8.8% by 2030, making interventions urgent. They recommend replacing diesel units with solar DG sets, adopting CPCB IV+ generators with stricter emission norms, gas-based solutions, and retrofitted emission control devices. Solar photovoltaic systems, though promising 100% emission reduction, currently meet only about 30% of demand due to high costs, land requirements, and reliability issues. Gas generators, capable of cutting PM2.5 emissions by over 95%, are hindered by steep costs, poor pipeline infrastructure, and safety concerns.Experts suggest policy-level interventions such as a national scrappage policy for ageing, highly polluting units, financial incentives for rooftop photovoltaic systems with storage, and subsidies for CPCB IV+ DG sets. They stress that older or poorly maintained diesel engines often violate Central Pollution Control Board (CPCB) standards, emitting far above permissible limits. These ageing sets, especially in urban areas with frequent power outages, act as “super-emitters.”
The study recommends mandatory periodic emission testing, strict enforcement against violators, and shifting industrial clusters to gas-based generators wherever piped natural gas (PNG) networks are available. Identifying and phasing out non-compliant units, researchers argue, is critical for achieving cleaner air in cities like Bengaluru.
