## Methane capture and co-generation at WWTP Kubratovo.

**The challenge**

The wastewater treatment plant of Sofia used to be a large consumer of electricity with annual intake of 18 500 – 24 000 MWh.

After the successful implementation of a co-generation system, the plant has gradually increased its energy self-sufficiency to reach a status of net exporter of electricity in 2015. In 2023 the WWTP of Sofiyska voda, part of Veolia managed to produce more than 12% of excess green electricity on top of its own consumption.

After the Kyoto protocol mechanism, Sofiyska voda, part of Veolia looked for other options to monetise emission reduction from the co-generation project and to boost its image as an environmental company.

**Veolia’s solution**

Sofiyska voda, part of Veolia decided to explorer the potential of voluntary emission reductions market.  
In 2014 the company embarked on a journey to certify the emission reduction reached as a result of the project through Gold Standard - the most stringent mechanism for voluntary emission reduction.

After a lengthy procedure for registration, the entity is able to certify emissions reductions for up to 21 years with an annual volume of > 70 KtCO2e.



 

 

 



 

 

**Sofia, Bulgaria**

**Contract Facts:**  
**Duration: contract started in 2000 and expires in 2034**   
**Type: Concession**

**630 000 tCO2e already verified (2014-2023)**

**average annual T/O EUR 200,000**



 

 

 

 

 

 





  [  ![](/sites/g/files/dvc2926/files/styles/default/public/image/2024/05/CST%20Sofia%20Municipal%20Bulgaria%20Water%20Golden%20standard_2024.png.webp?itok=aIQHo4AU)  ](/sites/g/files/dvc2926/files/document/2024/05/CST%20Sofia%20Municipal%20Bulgaria%20Water%20Golden%20standard_2024.pdf)  





 

 

 



 

 

 

 





**The benefits**

- The company is able to monetise emission reduction generated from its activity without being part of the EU ETS scheme.
- The Gold Standard mechanism is a strong environmental platform to enhance the contribution of Sofiyska voda to the ecological transformation.
- Participation in a mechanism that fights climate change provides the company employees with an additional sense of purpose
- Sofiyska voda contributes to the ecological transformation which is the Purpose of Veolia
- This is a flagship project for Sofia Municipality and contributes to its Green Sofia mission

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REGIONS & CITIES

Greener city  
Cost efficiency



 

 

 

 

 

 



 

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PLANET

Saving resources, reducing carbon emissions with over 70Kt p.a. and developing the circular economy



 

 

 

 

 

 



 

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WOMEN & MEN

Provides on-the-job training ground for young engineers