SATRA reduces its carbon footprint

Highlighting SATRA’s organisational carbon footprint during 2024 compared to previous years.

by Nicola Pichel-Juan

An ‘organisational carbon footprint’ measures the amount of carbon dioxide (CO₂) and other greenhouse gases (CO₂e) released into the atmosphere due to the activities of an organisation. This includes emissions from its own operations, as well as those taking place upstream and downstream in its supply chain.

This article reports on SATRA’s organisational carbon footprint during 2024. Previous articles in SATRA Bulletin described in more detail how a footprint is calculated and provided practical guidance on how to approach the process. For example, please see the information in ‘Organisational carbon footprint’.

An organisation reports its carbon footprint across three different ‘Scopes’ in line with the Greenhouse Gas Protocol. Table 1 provides examples of emissions sources for each of the three scopes.

Table 1: Examples of emissions sources for each of the scopes
Scope 1	Scope 2	Scope 3
Gas consumption	Electricity consumption	Freight
Fuel used in company vehicles		Business travel
Fugitive emissions such as refrigeration from air-conditioning systems		Employee commuting
		Water consumption
		Waste water
		Solid waste
		Capital purchases
		Purchases of everything not captured in another category

Organisations will often initially focus only on Scope 1 and Scope 2 emissions. These emissions are directly under the organisation’s control and typically easier to measure. However, it is important to consider that Scopes 1 and 2 emissions are typically the ‘tip of the iceberg’. For example, brands and retailers which source and purchase footwear for resale would have to include that footwear in their Scope 3 emissions, and those Scope 3 emissions could sometimes account for up to 90 per cent of the total organisational carbon footprint.

SATRA’s carbon footprint

Figure 1 provides details of SATRA’s organisational carbon footprint in tonnes CO₂e for our two UK sites over the last four years.

We have so far been able to make substantial progress in reducing our overall emissions – our estimated emissions for 2024 are 32 per cent lower than in 2021. This reduction has been achieved through various initiatives that we describe in more detail below.

Scope 1

The biggest source of Scope 1 emissions at SATRA is from refrigerants in air-conditioning systems. There are two sources of emissions from refrigerants: i) an assumed background leakage rate over time for each system, and ii) the actual amount of refrigerant that has been added to each system in the reporting period to fix faults.

Refrigerants have an extremely high global warming potential (or carbon footprint). A refrigerant that manufacturers often use today in new air-conditioning systems is ‘R32’, which has a global warming potential of 675 kg of CO₂e per kg of refrigerant. This is much lower than refrigerants which were previously used in older air-conditioning systems such as ‘R22’, which has a global warming potential of 1,760 kg of CO₂e.

At SATRA we are part-way through a programme to replace our legacy air-conditioning systems with more modern versions. This supports a reduction in our carbon footprint in multiple ways. Firstly, the refrigerants in new systems have a much lower global warming potential, therefore the impact of any leaks is much lower. Secondly, a newer system is less likely to have leaks. Finally, the energy efficiency of new systems is better, which also reduces our Scope 2 emissions through lower energy consumption.

Petrol and diesel consumed in company vehicles also contributes to our Scope 1 emissions. We are tackling this emissions source by starting to transition to electric vehicles.

Scope 2

Scope 2 emissions are associated with the electricity we use at our two UK sites. From 2022 to 2023, we were able to reduce our electricity usage by 12 per cent and were able to maintain that lower level in 2024, despite increased on-site activity (see figure 2).

To reduce our production of Scope 2 emissions, we have:

• reduced the amount of time during which our facilities’ heating/cooling systems are in operation
• adjusted the target temperatures for our heating/cooling systems
• removed excess lighting
• introduced timers to control lighting in certain areas
• focused on fixing leaks in our compressed air system that can be responsible for substantial amounts of ‘wasted’ energy.

As SATRA moves forward, it will be more difficult to continue to reduce our energy consumption. Nevertheless, we will continue to replace older systems and equipment with more energy-efficient modern equivalents. We are also looking into the option of generating our own energy on-site through solar panels.

Scope 3

Scope 3 emissions are the hardest to measure and to reduce, as they cover such a wide range of activities and purchases. Table 2 shows the Scope 3 categories for which SATRA collects data, as well as the source of this data.

Table 2: Scope 3 categories for SATRA data collection
Item or activity	Data source
Volume of water consumed at site	Bill from water provider
Volume of water discharged from site	Bill from water provider
Solid waste generated at site by waste type	Reports from waste contractors
International travel – rail travel, flights, and hotel accommodation	Internal records
Employee commutes	Staff survey
Freight/logistics	Reports from freight providers
All other raw materials used and items/services purchased	Spend analysis

Spend per category will often be the starting point for organisations measuring their Scope 3 emissions, which will allow them to identify emissions ‘hotspots’. However, data such as weight and distance travelled for freight, and weight and type of waste disposed of, will be much more accurate. For example, most freight forwarders and couriers will be able to provide reports with details of shipments that organisations can use to accurately calculate a carbon footprint. Waste contractors should also be able to provide details of how much of each type of waste they have removed from a site and how it has ultimately been processed. Each year we are sourcing more data directly from our suppliers, rather than simply relying on spend to calculate our Scope 3 emissions.

As part of our ongoing commitment to sustainability, we have enhanced the way we distribute the monthly SATRA Bulletin magazine by prioritising digital channels. This transition has contributed to a notable reduction in our Scope 3 emissions, particularly those associated with air freight.

However, other categories of Scope 3 emissions have increased due to increased testing and production activity, which means that we have purchased more raw materials. This highlights why it is always important to calculate an organisation’s ‘emission intensity’, as well as measuring its ‘absolute emissions’.

Emissions intensity

Emissions intensity is the measure of an organisation’s emissions compared with a relevant unit of measure. This could be financial turnover or a measure of output, such as units or pairs produced. Due to the wide range of activities undertaken at SATRA, we calculate our emissions intensity as tonnes of CO₂e per GBP million of turnover and are pleased to report that our 2024 emissions intensity was 10 per cent lower than in 2023, thus continuing a downward trend (please see table 3).

Table 3: SATRA’s emissions intensity (measured in tonnes of CO2e per GBP million of turnover)
Year	Emissions intensity
2021	235
2022	241
2023	169
2024	152

Publishing Data

This article was originally published on page 28 of the July/August 2025 issue of SATRA Bulletin.

Other articles from this issue »

---