Stringent Standards

New pollution control norms for DG sets

The Ministry of Environment, Forest and Climate Change (MoEFCC) has been notifying regulations to define the emission standards for diesel generator (DG) sets for more than a decade. These are enforced at the manufacturing end by the Central Pollution Control Board (CPCB) through product certification, which was introduced in 2005.

The MoEFCC first enforced emission norms for DG sets with a capacity of up to 800 kW in 2004. These were revised in 2013 under the CPCB II norms. In March 2016, new environment standards were notified for gensets running on liquefied petroleum gas (LPG), natural gas, diesel with LPG/natural gas, and petrol with LPG/natural gas. The new notification has not made any changes in the emission standards for DG sets as compared to the standards released under the CPCB II norms. However, there are new rules for genset manufacturers with regard to obtaining approvals as well as for noise pollution. The main aim of the new standards is to control the air and noise pollution originating from DG sets. These standards have been recommended by the CPCB after holding discussions with industries and other stakeholders.


The emission norms in India cover carbon monoxide, oxides of nitrogen (NOx), particulate matter, and unburned hydrocarbons (HC), and are specified based on the number of grams of these compounds present in the diesel exhaust when 1 kWh of electricity is generated. The norms will be applicable to original equipment manufacturer-built DG sets and conversion or retrofitting of existing DG sets is not permitted. The emission standards for smoke and particulate matter are applicable when diesel is used as fuel. These standards have mandated certification for DG sets in terms of Type Approval and Conformity of Production for air emission as well as noise emission. Manufacturers are required to obtain certification for engine products by empanelled agencies. This will not only help in regulating the unorganised sector but will also curb the illegal import of DG sets, which have higher air and noise emission values. Similar to the standards released in 2013, the emission norms have a combined cap on NOx and HC, which is in line with the practice followed in the US and Europe. This will provide flexibility to manufacturers to optimise emission reduction methods.

In addition, new noise limits have been defined in the notifications. The maximum permissible sound pressure level for a DG set with a rated capacity of up to 800 kW has been fixed at 75 dB at 1 metre from the enclosure surface. The state pollution control boards and the pollution control committees,  with the help of local civic authorities, will implement these standards.


The implementation of the new rules will result in more fuel-efficient generator sets, which will eventually benefit the end-customer. The new range of DG sets will come with improved technology, which will minimise pollution levels and help address climate change issues. Moreover, since the new notification has stringent norms, it will encourage Indian manufacturers to undertake technology upgradation and bring their gensets at par with those of global players. Moreover, the new norms will help consolidate the genset manufacturing industry in India, which is characterised by several unorganised players.

However, there are certain issues associated with the enforcement of stringent emission norms. For instance, the genset industry is likely to face challenges in terms of upgrading technology, developing innovative or alternative solutions, and making modifications to the engine design. Besides, the adoption of new and advanced technologies will lead to a 15-20 per cent increase in DG prices since engine upgrades entail significant expenditure in setting up additional facilities and infrastructure.

These challenges notwithstanding, the demand for DG sets is set to grow. The new emission norms will play a critical role in environmental protection and bring the Indian genset industry on par with international standards.


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