The campaign replaces the inefficient combustions plants of vulnerable households with alternative forms in order to improve efficiency and reduce air pollution
In Bulgaria, many vulnerable and low-income households rely on low quality wood and coal for heating, utilized in combustion plants with low-efficiency. Due to the overall inefficiency, households burn more wood than is technically necessary to stay warm, which drives up their costs and also creates additional indoor and outdoor pollution. The effect of this practice is winter air pollutants of PM10 that are several times higher than those during the summer season, proving the strong influence of the current heating patterns.
Nearly 55,000 households are using such heating model in Sofia. Recognising that the up-front cost of an efficient heating installation is a huge barrier for the vulnerable groups, Sofia Municipality is performing a campaign for the free replacement of wood and coal based combustion plants with new fully automated and highly efficient installations based on: pellets (incl. pellet boilers and pellet domestic heaters); air-to-air heatpumps. In some cases eligible participants may also connect to district heating network and to the gas distribution network, where a highly efficient condensing gas boiler is installed.
Nearly 20,000 vulnerable households, currently heated with coal and wood with high humidity, are eligible for a new efficient heating system. Thus, the practice contributes to greater thermal efficiency in the dwelling, increased share of renewable energy and lower energy costs for each vulnerable household and less air pollutants.

Resources needed

Each vulnerable household picks-up from a variety of efficient heating devices. The average price per household is estimated at 1,500 €. The total budget available for 20,000 households worth 31 M€ and is funded through OP “Environment”. Administrative and campaign costs are 5% of the total budget.

Evidence of success

• 20 000 vulnerable households equipped with efficient heating systems
• Increased energy efficiency in heating - from 45-55% efficiency to >90 % for the new equipment and SCOP >4.0 % for A2A heatpumps)
• Lower final energy consumption with at least 20%
• Decreased energy expenses
• Increased thermal comfort
• PM10 avoidance per household – 24.2kg
• Total PM10 avoidance 484 t/y
• Increased environmental awareness of the society in general due to large campaign

Difficulties encountered

Although the campaign provides an efficient new device for free for 20,000 households, only 5,500 have applied during the first stage. In overall, there is lack of culture of trust and difficulties in engagement and empowerment of citizens, especially the vulnerable groups.

Potential for learning or transfer

The described project foresees action aimed at the most vulnerable parts of the society, who often struggle to adequately heat their homes at reasonable price and comfort, creating opportunities for vast air pollution, due to their old and inefficient heating infrastructure. This phenomenon affects most of the European countries, however highly demonstrated in South-Eastern Europe. The project foresees implementation of efficient devices based on renewable energies among the most vulnerable groups. Citizens’ involvement, energy efficiency and renewable energies, air pollutions and awareness raising of environmental issues are EU top priorities. This makes this type of measure transferable among different countries and regions.

Please login to see the expert opinion of this good practice.

Main institution
Sofia Municipality
Югозападен, Bulgaria (България)
Start Date
February 2020
End Date


Petar Kisyov Please login to contact the author.