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WWTP of Sofia – close to 100 % self-sufficiency with green energy


Kubratovo wastewater treatment plant treats domestic, industrial wastewater and stormwater entering the sewerage network of Sofia. It was commissioned in 1984 and is now one of the largest in the Balkans.

WWTP Bulgaria Sofia



ONE OF THE LARGEST WWTP IN THE BALKANS

For 30 years, the facility has operated without interruption. Over the years there have been partial reconstructions and improvements funded by EU funds and Sofiyska Voda`s investment programme.
The plant is located in the lowest northern part of Sofia – Kubratovo, on a total area of 60 ha. Its design capacity is 500 000 m3 of wastewater per day. 
 

SELF-SUFFICIENCY WITH GREEN ENERGY

In 2009 a new co-generation system was installed in order to use the biogas and produce renewable energy. The aim was to optimize the operation of the plant and its energy efficiency as well as to reduce carbon emissions.

In 2010 Veolia acquired the majority stake in Sofiyska Voda and put in place new projects for optimization and environmental protection by reusing the waste from its activity. The production of green energy from biogas at the plant continued to increase steadily and in 2014 for the first time since the co-generation system was installed, Sofiyska Voda reached 98% self-sufficiency with green energy. The capacity of the co-generation installation includes three co-generators, each of them can produce 1063 kW of electricity  and 1088 kW of heating power. 
The next target for Sofiyska Voda is to achieve 100 % self-sufficiency with green energy for the WWTP

 
Bruno Roche​,
Veolia Country Director for Bulgaria

„We are resourcing the world when we are producing electricity by biogaz coming from the digestion of the sludge – as a result of the biological process of treatment of the waste water at Kubratovo wastewater treatment plant, enough to cover our needs for it.​“



Key figures
  • 19 M kWh of green energy produced in 2014 networks
  • 10.6 M Nm3 biogas utilized in 2014
  • 728 000 t CO2e reduced emissions since the installation of CHPs in 2009

The benefits for our client
  • greener city 
  • cost efficiency
  • protecting the environment by recycling waste
  • reduced carbon emissions
  • business to business solutions 
  • provides on-the-job training ground for young engineers

Learn how Veolia is resourcing the world
> See how we’re working to improve access to water