Introduction

Modernization of the district heating system in Plonsk was based on the replacement of the coal boiler to the biomass version, establishment  of the cogeneration system, as well as the thermo-modernization of the existing heat distribution system.

Objectives and target audience

The main aim of the project was to reduce the emission of GHG, as well as other pollutants i.e.: particular matter, sulphur dioxide, nitrogen oxide, etc.  However, it was also important to limit the energy losses from the generation and distribution processes.  Bearing in mind economical and environmental aspects, the cogeneration system (with the biomass boiler) was implemented.  The production of “green” heat and electricity was one of the most important project objectives.
Other objectives: Increase of energy renewable sources, increase density of the combustion process, decrease of the energy losses in the distribution system; implementation of BAT, etc.
Target groups: Energy Utility,  the citizens of Płońsk, farmers on the region;

Financial Resources and Partners involved

The total cost of the project was c.a. 33,7 million PLN.
Credit from National Fund for Environmental Protection and Water Management covered more then  53% (18, 8 mln PLN).  Polish EcoFund  donate 11,3 mln PLN (33%) for the project, and The City Hall of Płońsk – 1,8 mln PLN The PEC contribution was  4,6 mln PLN.
Process

• Modernization of a central source of heat:
• Replacement of the coal boilers (3x OR-16) with a new biomass boiler (VSP=10,5)  of 10,2 MW power;
• Established of the cogeneration system with the steam turbine of 2,1 MWe power;
• Setting up the monitoring and control system;
• The  purification of waste gases  system establishment;
• Modernization and adaptation of the existing coal boiler (WRM-15) to biomass co-combustion (up to 20%);
• Modernization of heating system:
• Exchange of 800 meters of the traditional pipe system for a the pre-insulated version;
• Modernization and exchange of heat centers (15 singe- and 14 multifunctional);
• Thermo-modernization of buildings owned by enterprise.

The project ended up with a decrease of the total power of the system from 50MW to 37,1 MW.  The modernization works will ensure that the amount of heat produced is enough to supply the heat demand for the city of Płońsk.

Results

The new cogeneration system will generate 67% of the total heat demand for the city.
11,000  MWe of energy has been produced from the renewable source, biomass.
An emission reduction is due to an  increase in density of the combustion process and a change of the energy source and thermo-modernisation works-:
The CO2 avoided emission is estimated for 35,000 Mg/year
The emission of particular matters will decrease for c.a. 76,7% (151, 11 Mg/year); nitrogen     oxide for c.a. 63,3 % (53,81 Mg/year); sulfur dioxide for c.a. 63,8 % (144 Mg/year);     benzo[a]pyrene will decrease for c.a. 98,6% (0,14 Mg/year), soot will decrease for c.a.     76,5% (4,81 Mg/year);
The coal consumption will decrease by c.a. 70% (10 thousand Mg/year);
Secondary dust explosions from the coal storage container will be limited;
Noise emission reduction in the boiler room;
A decrease of the solid waste (slag and ash) produced by c.a. 51%;
Demand for the biomass in the region will increase.  To supply cogeneration system, an amount of 25 Mg of biomass will be needed annually.  According to the PEC estimations the demand will create approximately 50 – 70 new job opportunities (in the agriculture and service sectors).

Critical Success Factors / Challenges

There is common practice in Poland with regards to the co-combustion of biomass and coal as it is one of the only solutions for increasing renewable energy use (There is a mandatory obligation by the energy utilities to produce an required amount of energy from renewable energy sources).  The project of “Modernization of the district heating system in Plonsk” is the first, which focuses on the renewable energy use in a more sustainable and efficient way.  This practice could be easily transferred to another municipalities.
The critical success factors were:-
Good recognition of economical and environmental advantages of the project;
Determination of the Local Energy Utility Management;
Fundraising opportunities : EcoFund, from National Fund for Environmental Protection and Water Management.