Statutory guidance

SR2018 No 4: Specified generator, tranche B low risk, 0 to 20 MWth operated less than 500 hours a year

Standard rules and generic risk assessment for tranche B specified generator with individual unit capacity 0 to ≤20 MWth of gas or abated liquid-fuel engines operated less than 500 hours a year.

Applies to England

Documents

Details

When referred to in an environmental permit these rules allow an operator to run one or more Tranche B Specified Generators for fewer than 500 hours per year. These units are gas or liquid‑fuel engines that may provide balancing services to the National Grid. Each unit must have a net rated thermal input of ≤20 MWth, and the total aggregated input at the site must also be ≤20 MWth, with sufficient local NO2 headroom. Liquid‑fuel engines must have secondary abatement, and gas engines must have it where required.

These rules apply to Specified Generators using only natural gas, hydrogen, ultra‑low sulphur diesel (10 ppm sulphur) or gas‑oil substitutes.

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Updates to this page

Published 6 September 2018
Last updated 26 February 2026 show all updates
  1. The rule set (and corresponding generic risk assessment) has been brought into HTML format. Conditions added for decarbonisation readiness. Hydrogen added as a new fuel type on this rule set with corresponding criteria and ELVs including using a blend with natural gas. Gas oil substitutes added as a fuel type with corresponding criteria. Addition of Marine Conservation Zone under the meaning of protected habitats. Reference to TGN5 replaced and addition of MCERTS monitoring as an option. Updates to the interpretation section to improve understanding.

  2. Updated the 'Details' section to linked to the new service for applying for a environmental permit online in England.

  3. Added updated standard rule.

  4. Added updated standard rule and associated generic risk assessment.

  5. First published.

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