Sustainability : Environmental Protection

Environmental Protection

Understanding of the environments in which we operate and committing to the development of energy solutions in environmentally responsible manner are at the core of the corporate sustainability efforts at AES. Environmental stewardship and leadership are a key part of our business, and we strive for excellence in the environmental performance of every business we own. We also go beyond simply meeting environmental standards, and we work to develop the right energy solutions for the markets in which we operate.

AES Bulgaria has taken a leadership role in diversifying its business solutions, in particular for wind, to make them more viable and relevant for the future. Additionally, in markets like Bulgaria, where fossil fuel generation is the right choice for development, we are working to ensure those resources are used in the most efficient, effective and responsible manner.


The environmental commitment is a guiding principle in the operation of TPP AES Galabovo. After becoming operational in 2011, it works entirely with local lignite from Maritza Iztok Mines. The production process ensures optimal management of all environmental components in full compliance with all European environmental legislation and best practices including Directive 2001/80/EC on the limitation of emissions of certain pollutants into the air from large combustion plants and is ready to meet the more stringent requirements of Directive 2010/75/EU on industrial emissions (integrated pollution prevention and control). TPP AES Galabovo was designed and operates in compliance  with  emission standards for sulfur dioxide (SO2) not exceeding 400 mg/Nm3 and desulfurization efficiency rate over 95%, nitrogen oxides (NOx) not exceeding 200 mg/Nm3 and dust less than to 30mg/Nm3.

Continuous Emission Monitoring System (CEMS)
CEM system for monitoring of  SO2, NOx, CO, dust, and process parameters is installed. Monthly and annual reports are submitted to the Regional Inspectorate of Environment and Water -Stara Zagora. The annual IPPC Permit Reports are publically available on the internet page of the Environment Executive Agency. See here

Flue Gas Desulphurization (FGD) System
The FGD system installed in the plant is utilizing the wet limestone technology for the desulphurization. According to the technical process no possibility for bypass of Flue Gas Desulphurization system exists. The flue gas is discharged into the atmosphere only through the FGD system. Thus, if or when the desulphurization process fails, the production of electricity also interrupts automatically. This measure guarantees operation of the plant only with working FGDs, achieving 98% efficiency rate and ensures protection of the air from pollution with sulphur dioxide.

Automatic Measuring Station
AES constructed an automatic measuring station in Galabovo. In the beginning of August 2008 the station was put into operation and transmits data in real time to the Regional Inspectorate of Environment and Water - Stara Zagora and to the Executive Environment Agency - Sofia. The station monitors ambient air quality in the region by the levels of the main four air pollutants – sulfur dioxide, nitrogen dioxide, PM10 and PM2.5.

In addition to that, for becoming more transparant, AES installed information board at the entrance of the plant that displays again in real time the current load and FGD efficiency rate.

Early Warning System
The Early Warning System for ambient air pollution in the region, in case of unfavourable atmospheric conditions is a prognosis tool for the levels of SO2, NOx and dust in the ambient air 48 hours ahead. This program software for air quality modelling was developed and commissioned in the period 2007-2012 as a joint project of all power plants in the region, environmental authorities and in partnership with scientists from the National Institute for Meteorology and Hydrology (NIMH). Based on the prognosis the thermal power plants are able to undertake measures for reducing the load, and respectively their emissions. Thus, the exceedance of the emissions limit values is avoided.

Wastewater Treatment
Various systems and facilities are installed in TPP AES Galabovo to ensure closed working water cycle. Waste water  from all  streams is treated and reused, which reduces the total quantity of production water. We operate with zero waste water discharge. The modern water treatment technology with Reverse Osmosis enables efficient and safe operation with minimal chemical use and maximum cycles of concentration while no harmful chemicals are discharged to the environment. 

The wastes generated by the operation of TPP AES Galabovo are collected, stored and treated, in compliance with European and Bulgarian regulations and permits.
The waste, formed in result of the combustion and desulphurization processes are bottom ash (slag), fly ash and gypsum. They are temporary stored in closed silos, equipped with dedusting systems.  The wastes are disposed at a specially-constructed waste disposal facility, 7 km away from the plant, where they are transported through a tube belt conveyor and by trucks.


The Waste Disposal Facility processes the waste in the most environmentally safe manner. The tube belt conveyor fully eliminates the risk of dust emissions during transportation. The facility has a system for active dust suppression at transfer areas. It has also special rollers with reduced noise emission and additional noise isolating cover in the residential areas it goes through Waste disposal facility is an engineered structure with reliable lower and upper isolation systems as well as separate drainage systems for leachate and rain water.
Some of the main advantages of the landfill are the reuse of leachate water for dust suppression and the environmental controls and monitoring system.
AES Galabovo has also developed a complete design for landfill reclamation.

Isolation Systems of the Waste Disposal Facility
A Lower Isolation System (LIS) is placed at the bottom of the cells of the Disposal Site. It prevents leachate infiltration in the soil and ensures effective ground water protection. The System is constructed in conformity with the provisions of the IPPC Permit, the regulations and the best engineering practices in the world. It consists of compacted mineral layer, drainage layer, geo membrane, geo textile and protective soil cover.
The Upper Isolation System is placed over the dumped waste upon reaching the cell capacity and consists of compacted mineral layer, drainage layer, and soil cover.

Water Management
The water management is performed via two basins – Contact Water / Leachate Pond and Clean Water Pond. The leachate water is used for active dust suppression.
The Contact Water Pond is a sedimentation basin where all waters passing through the dumped waste are discharged. To protect ground water from contamination, we have used a mineral screen and geo membrane and installed a Leakage Control System. The system enables high precision in localizing of any possible rupture in the membrane.

Post-closure Monitoring
In accordance with Regulation #6 for terms and requirements for construction and operation of landfills and other installations and facilities for waste utilization and disposal, as well as the IPPC Permit, AES shall monitor the facility for a period of 30 years after its closure. The activities after closure of the landfill include as follows:

  • Maintaining the integrity and effectiveness of the final cover including making repairs to correct the effects of settlement and erosion, and preventing run-on and run-off from eroding the cover.
  • Maintenance and operation of the leachate collection system.
  • Implementation of monitoring plan consisting of settlement monitoring and groundwater monitoring.

AES Geo Energy, the affiliate enterprise of AES which built and currently operates Saint Nikola Wind Farm close to Kavarna, develops its business with care for preservation of the environment and vision for the future. For the achievement of that objective, the company encourages and maintains open dialogue with all stakeholders – NGOs, representatives of municipal and state authorities, scientific circles.  The project entirely meets the environmental and social standards of the financing institutions – EBRD and IFC some of which are significantly higher than the requirements of the European legislation.

Prior to the start of the operation, AES Geo Energy carried out a 3-year preliminary seasonal monitoring of birds and bats based on which, in 2007 the Regional Inspectorate for Environmental and Water Protection (RIEW) Varna issued a positive decision on the Environmental Impact Assessment. The continuing from the startup of the wind farm in March 2010 permanent systematic monitoring, confirms lack of any significant negative impact to the populations of the birds and bats occupying or passing through the territory of the wind farm.

The environmental controls and monitoring measures are described in specially developed Environmental Management and Monitoring Plan approved by the financing institutions and RIEW Varna. It includes permanent periodic surveys of the wintering birds, autumn migration, breeding birds, bats, monitoring of the bird mortality due to collision with turbines, birds’ use of the wind farm area and its surroundings, habitat/crop surveys. All researches are made by competent Bulgarian and international experts.  All monitoring reports are published here .  

In March 2010, prior to the start of the operation of the wind farm, an operative turbine shutdown procedure was implemented to cessation of the turbines in case of increased risk of collision with birds aiming to reduce to minimum the probability of collisions of birds into the turbine rotors during their operation. The shutdowns are executed based on verbal orders from field experts ornithologists given to the duty engineer of the wind farm, who by the means of the wind farm operation system, executes the necessary shutdowns of turbines or if necessary the complete wind farm.

Saint Nikola Wind Farm has a certified Integrated Management System for Safety and Environment (IMS) according to OHSAS 18001 and ISO 14001 respectively.