Recovery of waste heat from cooler units within Thales Toulouse site’s data center, to provide heating for the site

Thales has installed a heat recovery system within its data center on its Toulouse site in order to reduce its carbon footprint by replacing gas heating with a system that uses the calorific energy produced by the data center. It is also used for the cooling and air conditioning of less energy-consuming systems, adjusting when necessary for seasonal cold weather conditions.

Main project's drivers for reducing the greenhouse gas (GHG) emissions

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Energy and resource efficiency

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Energy Decarbonisation

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Energy efficiency improvements

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Improving efficiency in non-energy resources

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Emission removal

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Financing low-carbon issuers or disinvestment from carbon assets

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Reduction of other greenhouse gases emission

Project objectives

In line with Thales’ strategy for a low-carbon future, the priority is to reduce, or even completely phase out, the use of fossil energy on our sites, in two ways:

- through the insulation of the buildings, since fossil energy (gas) is mainly used for heating purposes on our sites,
- by recovering the waste heat produced by industrial equipment and using it to heat our sites.

Refrigerant fluids in the cooler units used to maintain a low temperature in the data center constitute another source of carbon emissions.

Therefore, the project had three objectives:
(i) to recover the heat produced by the data center,
(ii) to replace the refrigerant fluids used in the cooler units by a gas that has a smaller carbon footprint and
(iii) install comfort cooler units whose electricity consumption adjusts according to the required cooling capacity.

Detailed project description

Replacement of old cooler units used on the site and in the data center by modern cooler units with heat recovery and more environmentally friendly gases, as well as injecting the hot water generated into the site’s heating system. 


As regards the comfort cooler units, the replacement of the units goes hand in hand with automated functions (linked to the BACS directive) enabling them to be operated according to the external temperature. Gas continues to be used in the event of intense cold conditions.

Emission scope(s)

on which the project has a significant impact

Scope 1

Direct emissions generated by the company's activity.

Scope 2

Indirect emissions associated with the company's electricity and heat consumption.

Scope 3

Emissions induced (upstream or downstream) by the company's activities, products and/or services in its value chain.

Emission Removal

Carbon sinks creation, (BECCS, CCU/S, …)

Avoided Emissions

Emissions avoided by the activities, products and/or services in charge of the project, or by the financing of emission reduction projects.

Scope 1 – Reduce the use of gas for heating purposes on site. Reduce emissions due to leaked refrigerant fluids from cooler units


  • 170 tCO2e/year are saved as regards heating compared to 2018 thanks to a 40% reduction of gas consumption for heating purposes.
  • On top of this reduction, there is also a reduction of emissions linked to recurrent leaks of refrigerant fluids from old cooler units (R134a).
  • For example in 2018, leaks represented 82kg of R134a, the equivalent of 118 tCO2e.       After changing the refrigerant fluids, replacing R134a by HFO ZE1234, a similar leak today would represent 82*7= 0.574 tCO2e (the GWP of ZE1234 being 7).     
  • Overall, thanks to these two drivers, 117.5+170 = 287.5 tCO2e have been saved compared to 2018.

Scope 2 – Increase the consumption of electricity via cooler units in order to recover the heat, compensated by ceasing to use gas for heating purposes.


  • Annual overconsumption of electricity due to heat recovery = an extra 191 MWh, equivalent to 11 tCO2e
  • This is compensated by savings made thanks to the installation of a variable flow cooler unit and improved EPC.

Calculation carried out as part of a contract relating to energy performance.

Key points

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Invested amount

€1.8 M financed 100% by the Energy Saving Certificates

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Starting date of the project

The project was launched in March 2020, and finalised in December 2020

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Project localisation

The project is located on the Thales AVS France SAS site in Toulouse, on which there is a data center used by several Thales entities.

Project maturity level

Prototype laboratory test (TRL 7)

Real life testing (TRL 7-8)

Pre-commercial prototype (TRL 9)

Small-scale implementation

Medium to large scale implementation

Heat recovery from cooler units has been implemented on 70% of units on the 14 Thales Avionics sites in France

Economic profitability of the project (ROI)

Short term (0-3 years)

Middle term (4-10 years)

Long term (> 10 years)

Illustrations of the project

Following this project, another project is underway on the Elancourt site, where data centers are in place, and this will enable savings of 1500 tCO2e per year.

Partnership with Vinci to carry out the project.

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Contact the company carrying the project

Thales’s other projects :