Medium Combustion Plant Directive – June 2026
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 applied, you should do this as soon as possible to avoid enforcement action.
Standard rules (SR) permit for new and existing low risk stationary MCPs and Tranche B Specified Generators
Standard rules permits are available for certain low risk MCP and SG operations; 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.
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
The guidance sets out which type of bespoke permit you must apply for and the information you will need to provide.
Apply using the Environment Agency’s new online environmental permission service
The Environment Agency has launched a new online service where you can apply for and manage environmental permissions in England. It is currently available for all new standard rules (SR) and bespoke applications for:
- Stationary stand‑alone medium combustion plant(s) (MCP)
- Stationary stand‑alone specified generator(s) (SG)
Please note: you cannot use the online service for variations or to add plant to existing SR permits, transfers or notifications of surrender.
Aggregation
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 <500mg/m3 NOX2 (@ 15% Oxygen) or; are operated for less than 50 hours per year.
EA review of MCPs listed as part of an Industrial Emissions Directive (IED) installations
For existing MCP between 5-50MWth which are listed as part of an Industrial Emissions Directive 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 also preparing a review of permits with exiting 1-5MWth MCPs before the 1st January 2030.
Regulator Position Statement (RPS) on Alternative Fuel use in MCP and SG
The RPS was published on 4th 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 1st October 2024 will have a condition which will allow substitute fuels to be used ‘as agreed in writing with the EA’.
The 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. As 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.
Regulatory Position Statement (RPS) on Monitoring of back-up generators
The RPS was published on 9th 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.
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 1st 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 the 28th February 2026, this mandate requires operators applying for an Environmental Permitting Regulations (EPR) permit for a new or substantially refurbished power generation facilities (including MCP and SG) to demonstrate how they can transition towards low-carbon technologies through a Decarbonisation readiness plan.
Permitting of existing MCP 1-5MWth and Tranche A SG less than 5MWth
Over the next year the EA will be preparing to open for applications to permit existing MCP 1-5MWth and Tranche A SG less than 5MWth.
