Sulphur dioxide emissions from US power plants falls faster than coal generation

• 7 years ago (2017-02-06)
• David Flin

Coal 296 Emissions 65 North America 1021

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Sulphur dioxide (SO2) emissions produced at power plants in the USA declined by 73 per cent from 2006 to 2015, a much larger reduction than the 32 per cent decrease in coal-fired generation over the same period, according to a recently released report from the US Energy Information Administration (EIA). The report said that from 2014 to 2015, the most recent year with complete power plant emissions data, SO2 emissions fell by 26 per cent, the largest annual drop in percentage terms over the decade. Nearly all electricity-related SO2 emissions are associated with coal-fired generation.

Several factors have contributed to lower SO2 emissions.

Changes in the electricity generation mix has resulted in generation from coal falling by 14 per cent from 2014 to 2015. This drop was mostly offset by an increase in generation from natural gas, with the net effect of lower SO2 emissions.

The installation of environmental equipment, notably dry sorbet injection systems (DSI) and flue gas desulpherisation (FGD) systems, resulted in plants burning 18 per cent less coal and reducing SO2 emissions by 49 per cent in 2015 compared with 2015. DSI systems were installed on 15 GW of coal capacity, and FGD scrubbers on 12 GW of coal capacity.

Lower utilisation of the most polluting plants has also contributed to the reduction. Power plants that produce more than two tonnes of SO2 per GWh were used less often in 2015.