District heating of Florina

The project of  Florina district heating system is currently being implemented. It is planned to cover the needs of indoor heating and hot water production for the city of Florina as well as the settlements of Melitis and Simos Ioannidis. The total rated thermal capacity of the system is 113 MWth. In the city of Florina, the nominal peak load is 68 MWth with a future estimate of 96 MWth.

Respectively, in the settlement of Melitis the nominal peak load is estimated at 7.7 MWth and in future at 8.4 MWth. The installation is a high temperature district heating system. The means of transporting thermal energy is superheated water with a maximum flow temperature of 120 ° C and a return temperature of 70 ° C. The transmission capacity of the transport pipelines according to the design amounts to 70 MWth.

The thermal energy performance of consumers will be indirectly made using thermal substations.


Implementing Entity



NSRF 2014-2020


70 MWth

Nominal capacity


Customer connections

Project details

The district heating system of Florina aims to meet the heating needs of the inhabitants of Florina in an environmentally friendly way, economic and beneficial to the national and local economy.

Within the framework of the project, the waste heat of the power generation process will be recovered at the PPC Melitis lignite-fired Power Station (PPC), aiming at the disposal of this heat for urban use (space heating and hot water production) in the city of Florina. The thermal energy transfer medium will be hot – superheated water.

Distribution of thermal energy

The thermal energy will be transported through a discrete underground transport system to the city of Florina and will be distributed to the buildings via two-way underground distribution steel pre-insulated network pipes. The thermal energy performance of the building's central heating systems will be achieved through thermal substations of buildings.

The circulation of water in the closed district heating network system will be achieved by means of circulation pumps installed in the transportation and distribution pumping stations. It is planned to construct a total of three main pumping and distribution pumping stations. At the same time, the construction of two auxiliary thermal pumping stations is planned to optimize the hydraulic function within the settlement of Florina.

Peak & Reserve Load Coverage

Peak & Reserve Load Coverage

In order to strengthen the system in times of peak demand as well as for back-ups, and in order to increase the reliability of the installation, a boiler room is provided, consisting of hot water boilers, a pressurized combustion chamber. The boiler room will be able to burn light oil (EL – heating) or, alternatively, LPG. In order to maximize the energy balance of the system of RES retrieval and concomitant thermal energy, as well as to normalize the operation of the heat recovery units in the WWTP and the transport system, a 24-hour heat storage system consisting of water tanks is provided.

Gain of thermal power

Thermal power input

The recovery of the thermal energy will take place at the PPC lignite-fired power plant of Meliti.  A two stages thermal gaining system from the steam turbine of the unit, will be installed.

It is planned to install two preheaters – steam condensers – water to heat the water of the district heating networks from the recovered steam.

Basic features of the installation

The main features of the proposed system of district heating in Florina, in its full development, will be:

  • Transmission pipelines

    It is envisaged to build an underground network of steel pre-insulated transport pipes according to EN253. The transport pipelines will run from the A3 and A4 main pumping stations (sited inside the Melitis power station) to the associated settlements. The transport pipeline to the city of Florina has a nominal diameter of DN450 mm and an estimated drilling length of ~ 14.3 km.

    Respectively, for the settlement of Melitis, the pipeline will have a nominal diameter of DN200 mm and a drilling length of 2,9 km. The transport pipeline of the settlement of Melitis will be directly connected to the distribution network of the settlement.

    Instead, the transport pipeline to the city of Florina will end up at the A1 / A2 peak / A1 boiler station.

  • District Heating distribution network

    It includes the construction of thermal energy distribution networks in the city of Florina and the associated settlements.

    For the city of Florina, there is provision for the construction of a divalent underground network of steel pre-insulated pipes according to EN253. The estimated trench length for the distribution network is 52.3 km and nominal conductor diameters DN25 up to DN50 mm.

  • Construction of building connections

    The project includes the full construction of 2,534 building connections to te system for the heat energy supply to the final consumers. The construction of the network will be of pre-insulated steel conductors, range of nominal diameters DN20mm to DN100mm.

  • Infrastructire for receiveing the thermal capacity

    The construction of all the necessary infrastructure for receiving the thermal capacity input from the lignite-fired power station of Melitis SA. Including the modifications within the power plant of  PPC Meliti. The modifications include the installation of condensers/exchangers and pipeline sections for the interconnection of the A3 pumping station with the power plant.

    The above equipment shall ensure the thermal supply of the district heating of Florina with the demanded capacity up to 70 MWth from the Melitis Power Station.

  • Αντλιοστάσια Μεταφοράς & Διανομής

    The construction of pumping stations for the transmission and distribution of thermal energy. Construction of building facilities, supply and installation of electric and mechanical pump equipment in A1 and A2 and pumping station Α3 / Α4 are foreseen. C.

    In order to ensure the functionality of the network, the construction of two auxiliary thermal heating pumping stations B1 and B2 in the city of Florina is also planned. Transfer pumping stations will operate in series with a capacity of ~ 1,200 m3 / h.

    The capacity of the central pump station was set at 1.900 m3 / h.

  • Peak load Boiler house

    The construction of a peak/reserve boiler house. The boiler house as well as the distribution pump station for the city of Florina is planned to be located on the 2506, 2508 and 2509 plots of the Florina farm in a total area of about 18 acres.

    In the boiler house, two (2) hot water boilers of pressurized combustion chamber will be installed with a rated capacity of ~ 27.5 MWth each. The boilers will be able to burn light oil (EL – heating) or, alternatively, LPG.

  • Construction of heat accumulators

    The construction of thermal energy storage overgound steel tanks. The tanks will be constructed in 2 to 4 units and will be located in the western part of the city of Florina.

    The total volume of heat storage containers will total ~ 1800 m3. The instantaneous charging / discharging capacity of the containers will be ~ 30 MWth. The total thermal energy storage capacity is estimated at 95 MWhth.

Funding the project

The “District Heating system of Florina” project is co-funded by the NSRF 2014-2020. By Decision 8359 / 18.07.2017 (ADA: ΨΚΤΦ465ΧΙ8-ΔΙ0) has been included in the Operational Program for Transport, Environment and Sustainable Development 2014-2020 in the Priority Axis “IMPLEMENTATION OF LOW CARBON DIOXIDE EMISSIONS IN THE URBAN AREAS”.

The total budget of the project amounts to € 54,079,477. Of these, € 9,767,432 are the same participation of the Project Implementing Body – Owner.

The rest of the expenditure is expected to be covered by the European Regional Development Fund and the Public Investment Program. Financial figures are reported before deduction of Contractors and include VAT.

Implementing Entity – Project Owner


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