Environmental Authorisations (Scotland) Regulations 2018: ​Proposed Standard Conditions for Registration level activities

Closes 24 Nov 2024

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3.2.10. Generators of electricity aggregating to 1 megawatt thermal (MWth) or more

Individual combustion plants that generate electricity with a rated thermal input of 1 megawatt (1 MWth) or more, currently require a Permit from SEPA. Smaller combustion plant (or plants) that generate electricity aggregating to 1 MWth or more at one location, are not regulated. However, they can have a significant impact on air quality.

Scottish Government has proposed the addition of a new activity to EASR to ensure this type of plant is regulated appropriately.

Activity description

Burning any fuel in combustion plant generating electricity on the same site with an aggregated rated thermal input of 1 megawatt or more.

Standard conditions

Below is the list of core and activity-specific standard conditions for generators of electricity aggregating to 1MW.

  1. All reasonable steps must be taken to minimise emissions during start up and shut-down of the process.
     
  2. All releases to the air from the authorised activities, other than condensed water vapour, during normal operation must be free from visible emissions.
     
  3. Emissions of substance(s) to the air from the combustion plant must not exceed the relevant emission limit value specified in Table 1.
     
  4. Air must not be added to dilute emissions in order to achieve emission limit values specified in Table 1.
     
  5. The emission of any other substance, not specified in Table 1 from the combustion plant must not cause environmental harm.
Table 1: Emissions limit values from combustion plant
Substance Emission Limit Value (mg/m3)
Oxides of Nitrogen (NOx) 190
  1. Monitoring must be undertaken at the combustion plant stack(s) at the sample port, frequency and using the monitoring standard as specified in Table 2.
     
  2. Monitoring must be undertaken during normal operation when combustion plant is:

    a.     operating under stable conditions at a representative even load;

    b. not undergoing start-up or shut-down; and

    c. for dual fuel or fuel mix plants, when firing the fuel or fuel mix, likely to result in the highest level of emissions.
     
  3. Sample locations must be provided, maintained and appropriately identified so that representative samples of emissions may be safely obtained.
     
  4. The first monitoring of emissions must be undertaken within four months from the start of operation of the authorised activities.
Table 2: Monitoring requirements
Substance Emission Point Reference Monitoring frequency Monitoring standard
Oxides of Nitrogen (NOx) Sample port determined in accordance with BS EN 15259 Once every 3 years BS EN 14792

  1. SEPA must be notified via its pollution hotline contact telephone number as soon as reasonably practicable, and in any case within 24 hours of identification of an event, of any of the following:

    a. an event that has caused or could cause adverse impact to the environment or harm to human health;

    b. an event that results, or could result, in an emission to the environment that is not authorised; and

    c. an event that has caused a breach of a condition of this authorisation.

    In this condition, the meaning of ‘event’ is as defined in the Interpretation of Terms of this authorisation.

  2. All measures that are reasonably practicable must be taken to stop an event and to minimise its effect on the environment.
     

  3. Within 14 days of an event a report must be submitted to SEPA detailing:

    a. the reason(s) for the event;

    b. the action(s) taken to stop the event and minimise the impacts; and

    c. the action(s) taken to prevent the event from reoccurring.
     

  4. All information recorded, kept or submitted to SEPA in accordance with a condition of this authorisation must be:

    a. true and accurate; and

    b. kept for a minimum of six year; and

    c. provided to SEPA upon request.
     

  5. Records must be kept of the following:

    a. the type and quantity of fuel used;

    b. number of hours plant(s) is operational per year;

    c. the effective continuous operation of secondary arrestment equipment, if it is being used; and

    d. any breakdown or malfunction of secondary arrestment equipment, if it is being used.

  6. The results of the monitoring of emissions, as described in Condition 6, must be submitted to SEPA no later than 8 weeks from the date the monitoring took place via email to registry@sepa.org.uk.

Interpretation of terms

Interpretation of terms
Term Definition
Arrestment equipment Equipment used to mitigate the effects of emissions.
Combustion plant Means any technical apparatus in which fuels are oxidised in order to use the energy generated to provide electricity. 
Dual fuel plant (or engine) An internal combustion engine which uses compression ignition and operates according to the Diesel cycle when burning liquid fuels and according to the Otto cycle when burning gaseous fuels. Dual Fuel combustion plant is capable of burning more than one fuel without a significant change to the setup, for example, natural gas and diesel. 
Emission Limit Value for generators of electricity aggregating to 1 megawatt thermal (MWth) or more

The mass, expressed in terms of specific parameters, concentration or level of an emission, which may not be exceeded during one or more periods of time.

All emission limit values are defined at:

  1. a temperature of 273.15K;
     
  2. a pressure of 101.3kPa; 
     
  3. after correction for the water vapour content of the waste gases; 
     
  4. at a standardised oxygen content of:
     
    1. 6% for combustion plants using solid fuels;
       
    2. 3% for combustion plants, other than engines and gas turbines, using liquid and gaseous fuels;
       
    3. 15% for engines and gas turbines.
Environmental harm
  1. Harm to the health of human beings or living organisms,
     
  2. Harm to the quality of the environment, including:
     
    1. harm to the quality of the environment taken as a whole,
       
    2. harm to the quality of air, water or land, and
       
    3. other impairment of, or interference with, ecosystems,
  3. Offence to the senses of human beings,
     
  4. Damage to property, or
     
  5. Impairment of, or any interference with, amenities or other legitimate uses of the environment.
Event
  • Any accident which has caused or could cause environmental harm; or
     
  • Any malfunction, breakdown or failure of plant, infrastructure or techniques which has caused or could cause environmental harm; or
     
  • Force majeure or action taken to save human life or limb.
Fuel Means any solid, liquid or gaseous combustible material. 
Normal operation Operation of authorised activities excluding start-up and shut-down periods.
Oxides of nitrogen Nitric oxide expressed as nitrogen dioxide (NO2) and nitrogen dioxide, expressed as nitrogen dioxide (NO2).
Rated thermal input The rate at which fuel can be burned at the maximum continuous rating of the appliance multiplied by the net calorific value of the fuel and expressed as megawatts thermal. 

Rationale

This is a new activity under EASR, however the standard conditions proposed are broadly similar to conditions for sites operating Medium Combustion Plant, reflecting the comparable risk to the environment of both activities. The main control is the requirement to monitor emissions of oxides of nitrogen (NOx).

 

91. Do you agree with the list of standard conditions for the burning any fuel in combustion plant generating electricity on the same site with an aggregated rated thermal input of 1 megawatt or more?