Find out if you need a permit for your boiler, engine or turbine
If you operate your own boiler, engine, generator (including back-up/stand by) or turbine for the production of heat, steam, power or electricity, you may be running a Medium Combustion Plant (MCP) and/or specified generator, and it is likely you will have to apply for a permit from us to continue using it.
A medium combustion plant is equipment used to burn materials (including waste) with a rated thermal input of between one and 50 megawatts, including:
- a combustion unit, such as a boiler, engine, generator (including back-up/stand by) or turbine
- any abatement
- the attached stack or flue
- air cooling, where it’s part of the combustion unit
Boilers, engines, generators and turbines will be referred to as MCPs throughout this guidance.
You will not need a permit if the rated thermal input (th) of your combustion plant is less than 1 megawatt (if your MCP produces electricity, you may need a specified generator permit, please check the specified generator definition below).
Some MCPs are exempt from the need for a permit.
Apply for an MCP permit
If you already know you need to apply for an MCP permit and understand what information and assessments are required with your application, you can apply now.
If you are not sure whether you need a permit, or what you must do, you can use our tool to help you determine if your boiler, engine, generator (including back-up/stand by) or turbine is classed as a medium combustion plant or specified generator, whether it needs a permit and by what date.
To complete the tool, you will need to know:
- The size of your medium combustion plant (expressed as megawatts thermal input). If you do not know the size of your medium combustion plant, you can use the medium combustion plant guidance on gov.uk to help you calculate it
- The date your medium combustion plant was first put into operation
- The fuel used by your medium combustion plant
- Whether your medium combustion plant is used for heat, steam, power and/or electricity
If after using the tool, you’re still not sure about whether you need a permit, or what you must do, please contact us for advice.
When do I need a permit for my boiler, engine, generator or turbine?
If you want to start operating a new MCP between 1MW and less than 50MW thermal input, you must apply for a new permit if you don’t have one already, or apply to change your current permit, so that you can meet the new requirements.
If you have an MCP which first came into operation before 20 December 2018 (known as an existing MCP) between 5-50MW thermal input, you need to apply for a permit now in order to meet the 1 January 2024 permitting requirements.
If you have an MCP which first came into operation before 20 December 2018 (known as an existing MCP) between 1-5MW thermal input, you need to apply for a permit in 2028 in order to comply with the 1 January 2029 permitting requirements.
If you’re unsure when you need a permit by, please ask us for help.
Specified generators are medium combustion plants used to generate electricity.
They are divided into Tranche A and Tranche B categories, depending on their operational start date or the type of electricity supply contract.
You can use our find out what permit you need tool to find out if your specified generator is Tranche A or B and when you need a permit by.
The term ‘specified generator’ covers an individual generator or a number of generators if they’re:
- on the same site
- operated by the same operator
- for the same purpose (generating electricity)
Generators are still classed as operating for the same purpose if they’re:
- using different fuels or technologies
- under contract for a capacity marketing agreement or to provide a balancing service
If you have more than one generator on your site, you’ll need to aggregate your generators into a specified generator. You’ll need one permit for the site.
Some generators are excluded from the specified generator controls so you should check the specified generator guidance on gov.uk before applying for a permit.
Specified generators for research and development
Standard rules permits
No new standard rules permits will be issued for medium combustion plants or specified generators.
If you already hold a standard rules permit, you can download the details below.