Medium Combustion Plant Directive (MCPD) – 6thMarch 2026

Posted on 9th March 2026

Medium Combustion Plant Directive (MCPD) Update

To comply with the requirements of the Environmental Permitting Regulations (EPR), Schedule 25A & 25B you need a permit from the Environment Agency (EA) for the following:

New standalone MCPs between 1-50MWth (before it is commissioned)
Existing standalone MCPs between 5-50MWth
Tranche A and B specified generators (permitting date requirement varies)

If you need a permit and have not already submitted an application, you should do this as soon as possible to avoid enforcement action in line with the Environment Agency’s enforcement and sanctions policy. If you want to report illegal operations, please contact enquiries@environment-agency.gov.uk or call on 03708 506 506.

Standard Rules Permit for new/existing low risk stationary MCPs and Tranche B Specified Generators

Standard rules permits are available for certain low risk MCP and SG operations, these are the quickest and cheapest option available.

To apply for a SR permit you must be able to meet the rules and criteria set out in the permit, if you cannot you need to apply for a bespoke permit.

Following consultation with stakeholders the Environment Agency (EA) have recently published some amendments to the standard rules sets and associated generic risk assessments for MCP and SG, the changes apply to all current standard rules permit holders from the 26^th February 2026.

Bespoke Permits for existing standalone MCP 5-50MWth

If you cannot meet the conditions in a standard rules permit, you must apply for a bespoke permit. There are 2 types:

Simple bespoke (low risk) – does not require detailed air dispersion modelling
Complex bespoke (high risk) – does require detailed air dispersion modelling

Aggregation

We would like to draw your attention to the guidance on aggregation. In summary:

You only need to aggregate NEW MCP where they share a common stack.
You should not aggregate existing MCPs even if they share a common stack.

Back-up Generators

Back-up generators (operated for less than 50 hours per year for testing) which are also Medium Combustion Plant DO require permitting at the relevant date.

Tranche A Specified Generators greater than 5MWth

An Environmental Permit was required by 1st January 2025 for Tranche A Specified Generators with individual or aggregated capacity greater than >5MWth thermal input with emissions which:

Have an emission of NO2 <less than 500mg/m3 NOX2 (@ 15% Oxygen) or;
Are operated for less than 50 hours per year

The Standard ELV of 190mg/m3 NOX2 will need to be met by 1st January 2025 for all Tranche A generators of this capacity operated for more than 50 hours per year, unless they do so to meet a capacity market agreement from the 2014 and 2015 Capacity Market Auctions that remain in force.

EA review of MCPs which are listed as part of an Industrial Emissions Directive Installations Permit

For existing MCP between 5-50MWth which are listed as part of an Industrial Emissions Directive (IED) Installation permit the EA has now completed a review of these permits and in some cases have carried out EA led variations to add in the requirements for monitoring and emission limit values (ELVs) to meet the requirements of the medium combustion plant directive as a minimum.

If your IED permitted facility has directly associated activities or primary activities made up of existing 5-50MWth or new 1-50MWth MCPs which are not currently permitted, you should apply to vary your permit as soon as possible to remain compliant with the regulations.

The EA are now carrying out compliance checks to ensure that operators are monitoring and meeting these ELVs.

The EA are also preparing for a review of permits with exiting 1-5MWth MCPs before the 1^st January 2030. As part of these preparations, the EA will be contacting operators in the intensive farming sector to gather information about in scope existing 1-5MWth MCP at their chapter II IED facilities.

Medium Combustion Plant Screening Guidance

The guidance for screening has been updated to provide instructions to applications for how to screen back-up generators. Key updates include instructions that:

Applicants are instructed to set operating hours to match their testing regime, to a maximum of 50 hours per year.
Emergency use hours related to power outages do not need to be included in the assessment.
Applicants must now provide information about their testing schedule, including typical and maximum test durations.
Applications should also include evidence relating to the likelihood of power outages, such as:

Historical data of frequency and duration of outages
Any planned infrastructure upgrades or maintenance that may influence reliability

Guidance for Setting Emission Limit Values for new Fuels

The EA has been directed by the secretary of state to set ELVs for new fuels. On the 14^th October 2024 the Environment Agency published guidance which explains how to meet emission limit values for hydrogen combustion plants over 1MWth. It set ELVs for oxides of nitrogen (NOx) and Carbon Monoxide (CO) aiming to ensure no increase in NOx or CO emissions compared to the combustion of natural gas.

Hydrogen fuel including blending with natural gas is now permitted on certain standard rules MCP and SG permits. You can also apply to use Hydrogen as a fuel on a bespoke MCP and/or SG permit.

Alternative Fuel use in MCP and SG

The Regulator Position Statement (RPS) was published on 4^th July 2025. It allows substitutes to gas oil such as HVO (Hydrotreated vegetable oil) to be used without requiring a permit variation. Permits issued since 1^st October 2024 will have a condition which will allow substitute fuels to be used ‘as agreed in writing with the EA’, this RPS covers the gap for older permits until they are revised through operator led variations or an EA led permit review, at which point the RPS will be withdrawn. There are likely to be more alternative fuels coming forward in the future e.g. Industrial Heating Oils, the RPS may be updated in future to add more substitute fuels.

Monitoring of back-up Generators

The RPS was published on 9^th July 2025. It allows operators to seek agreement for no or reduced monitoring of back-up generators (i.e. limited hours MCP) where no safe or permeant means of sampling is available. This has been put in place to reduce the regulatory burden on operators where there is no ELV to be met and no means to monitor emissions safely.

Mobile Boilers

The RPS was published on the 7^th July 2025. It removes the requirement for an environmental permit where temporary steam and hot water boilers are hired as replacement for stationary boilers (i.e. there is no increase in operational installed capacity) whilst the EA develops a more proportionate permitting approach for mobile boilers. This RPS includes use of mobile boilers at permitted regulated facilities.

Subsistence charges for MCP and SG Permit Holders

Medium combustion plant (MCP) annual subsistence costs for bespoke permits have previously been made using time and materials charges. From the 1^st July 2025 the EA now use fixed rate annual subsistence charge for bespoke MCP and SG permits, instead of Time and Materials charges. The EA have also decided to standardise the charges paid across standard rules and bespoke MCP and SG permits depending on how many combustion plants are operated.

Decarbonisation Readiness (DR)

The Environment Agency has been assigned a new duty focused on Decarbonisation Readiness for power generation. Effective from 28^th February 2026, this mandate requires operators applying for an Environmental Permitting Regulations (EPR) permit for new or substantially refurbishing power generation facilities (including MCP and SG) to demonstrate how they can transition towards low-carbon technologies – either carbon capture or conversion to hydrogen – through a Decarbonisation readiness plan.

Existing MCP 1-5MWth

Over the next year the EA will be preparing for applications to permit existing MCP 1-5MWth. As part of this the EA will be looking at expanding their offering of standard permit rules via a consultation and considering ways to stagger applications into the EA’s permitting service before the 1^st January 2029 deadline. The EA do not yet have a date when they will be ready to receive these applications; but will communicate this via briefing notes.

2EA

For organisations affected by the Medium Combustion Plant Directive (MCPD), staying compliant with Environmental Permitting Regulations is essential to avoid enforcement action and operational disruption. If you are unsure whether your plant requires a permit, need support with a new application, or require assistance with standard rules or bespoke permits, 2EA can help. Learn more about our Medium Combustion Plant Directive consultancy service and how we support operators through the permitting process.