New regulations for emission measurements for medium-sized combustion plants from 2025

A new EU directive, the Medium Sized Combustion Plant (MCP) Directive, has resulted in a new Danish executive order applying to medium-sized combustion plants with a nominal thermal input of more than 5 MW and less than 50 MW. From 1 January 2025, these plants will be subject to the environmental requirements in the executive order on environmental requirements for medium-sized combustion plants.

The executive order applies to 543 medium-sized combustion plants, many of which may not have had emissions measured before

The many medium-sized combustion plants are distributed among gas turbines, engines, and boilers, which use fuels such as solid wood biomass, gas oil, or natural gas, all covered by the new executive order. From now on, they must undergo emission measurements for e.g. CO and NO^x.

Some of the plants are either peak load or emergency units. That means they are either ready for start-up as needed, e.g., during particularly cold winter periods or scheduled shutdown of large plants, or in emergencies, such as power outages affecting critical infrastructure like hospitals or data centers.

The executive order has consequences for plants now required to have emissions measured, which might never have been measured before or now require measurement by different methods than usual. Additional measurements may also be necessary, meaning that plants must have emissions measurements performed at shorter intervals.

The timeframe for conducting emission measurements is only 7 months

The window for emission measurements is just 7 months, and all measurements must be performed by 30 April 2025.

Therefore, it is important for medium-sized combustion plants to quickly contact a measurement company to book a time in the calendar to ensure the measurements are done before the deadline and to comply with the requirements from the authorities.

Risk of lack of measurement site or poor access at medium-sized combustion plants

Many plants that have not previously had emissions measured do not have a designated measurement site or access conditions that make it possible to perform the measurement without significant preparations, such as establishment of access points and safe conditions.

The Danish Environmental Protection Agency requires the arrangement of measurement sites as described in the EPA's method sheet MEL-22, published by the Reference Laboratory for air emission measurements.

As stated in MEL-22, measuring concentrations of, for example, CO and NO_x does not demand extensive requirements for the measurement site's setup. However, if flue gas flow and/or formaldehyde must be measured, the process is much more complex.

Furthermore, many of these plants are not prepared for measurements, meaning it must be ensured that the measurement company can gain safe access to chimneys and that the measurements can be carried out in accordance with the guidelines in MEL-22.

The flue gas flow rate must be known to determine B-values for air pollution

For newer plants, it may also be necessary to assess whether the B-values are met. B-values, also called "contribution values," are limits for how much a company may contribute to air pollution in the surrounding area (e.g., at neighboring properties).

To calculate whether the B-values are exceeded, it is required to know the flue gas flow from the chimney. The flue gas flow can be measured directly or, in some cases, calculated based on knowledge of the fuel composition, fuel consumption, and the oxygen concentration in the flue gas. In certain cases, formaldehyde must also be measured (for engines).

Book your emission measurement in good time

Contact us if you need to have the required accredited emission measurements performed by 30 April 2025, or if you need advice, e.g., regarding the arrangement of measurement sites.