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Medium Combustion Plant Directive

Medium Combustion Plant Directive

02 July 2018

The Medium Combustion Plant Directive (MCPD) is a piece of EU legislation which has been adopted in the UK to limit the emissions of certain pollutants from medium combustion plants, with the purpose of improving air quality.

Under the MCPD, all combustion plant between 1 and 50MW will have to register or have a permit.  Any plant below 1MW in size is below the scope of the regulations.  The MCPD is, in part, a direct response to the rise in the number of biomass-fired boiler systems and CHP plants being installed across the EU, and to the need to clean up air pollution from other forms of combustion.

From 20 December 2018, all new plant will need to be registered or have obtained a permit and comply with Emission Limit Values (ELVs).  The ELVs to be applied are dependent on plant, fuel type and size.  Existing plant must be registered or have obtained a permit and comply as follows :



Comply with ELVs


1 January 2024

1 January 2025


1 January 2029

1 January 2030

The limit for emissions for existing biomass-fired medium combustion plants with a rated thermal input of between 1MW and 5MW will be 50mg/Nm3for dust and 650mg/Nm3for NOx, while for new plants (i.e. those installed after 20 December 2018) will be 20 mg/Nm3for dust and 300 mg/Nm3for NOx.

These new regulations are considerably tighter than those in place for boilers installed under the RHI, and will require new boilers to meet a particulates standard which is around a third of the current RHI emissions limit, and a NOxstandard which is around two thirds of the current limit.