Medium Combustion Plant Directive and Generator Controls

Air pollution is the biggest environmental risk to public health in the UK. Whilst air quality has improved significantly in recent decades, and will continue to improve thanks to the action the Government has already taken, there are some parts of our country where there are unacceptable levels of air pollution. The Government is committed to tackling this and improving air quality, and is working to make sure that concentrations of nitrogen dioxide (NO2) come within statutory limits. We are also looking to reduce total emissions of air pollution through legally binding reduction targets for 2020 and 2030. These proposals will help deliver these reductions.

Medium-sized combustion plants (MCPs) and generators are a largely unregulated, significant source of emissions of air pollutants. Implementation of the MCP Directive and regulation of generators will make a valuable contribution to improving air quality by providing an estimated 43% of the sulphur dioxide emissions reduction, 9% of the reduction for particulate matter, and 22% of the nitrogen oxides emissions reduction required to meet the 2030 targets. These controls will also contribute to reducing urban NO2 concentrations alongside measures on vehicle emissions in the ‘UK plan for tackling roadside nitrogen dioxide concentrations’.

Medium Combustion Plant Directive (MCPD)

Medium Combustion Plants (MCPs) are used to generate heat for large buildings (offices, hotels, hospitals, prisons) and industrial processes, as well as for power generation. Implementing the Medium Combustion Plant Directive (MCPD) will help to reduce air pollution by bringing in emission controls for these combustion plants in the 1-50MWth range. The MCPD was supported by the UK as it will deliver a cost-effective improvement in air quality. The Directive requires all plants in scope to be registered or permitted and sets limits on the levels of pollutants that these plants can emit. It also requires operators to test emissions from their plants to demonstrate compliance with emission limits. The controls will apply to new plants from December 2018. Existing plants must be permitted from 2024 (and comply with requirements from 2025) or 2029 (and comply from 2030), depending largely on size.

Generator controls
Within Great Britain, there has been rapid growth in the use of low-cost, small scale flexible power generators in the past few years. Whilst there is a legitimate role for some rapidly-responding small-scale generation, there has been a recent growth of (mainly diesel) generators which emit high levels of NOx relative to other MCPs and are not subject to emission controls. This growth poses a concern for local air quality as well as for meeting future national emission reduction targets.

The MCPD requirements are not sufficient to tackle emissions from the increased use of these generators. Our proposed generator emission controls mean that new generators will be subject to permitting and a NOx emission limit from 1 January 2019. Existing generators will not need to meet the emission limit until a later date. This date depends on their size, their emissions, and whether they have an existing agreement with National Grid. These transitional agreements will be removed if the operator signs up to a new agreement with National Grid after 31 October 2017 (which remains in place after 31 December 2018). This is to avoid favouring and encouraging the use of older, more polluting generators, whilst also providing time for the market to adapt.

The controls are designed to protect air quality whilst minimising impacts on energy security and costs to businesses. We have worked closely with other government departments, including BEIS, to ensure this is the case.

Environment Medium Combustion Boilers


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