For the power and heat plant in Katowice, the beginning of the heating season meant increased operation of the power generation equipment resulting from huge demand for thermal energy. During the period of low temperatures and cold winter, PEC Katowice (Thermal Energy Company) ordered 230 MWt of energy per hour on average. This demand was satisfied by the operation of BCF-100 power unit, which generates nearly 200 MWt electric and thermal power as well as peak operation of one of two WP-120 water heaters of 140 MWt each. Nonetheless, this season is quite different, weather does not favour thermal power industry, and the power generated by the main power unit, which for the first two months of this year produced 140 MWt of thermal power on average, is sufficient to meet the demand.

Pursuant to the Act pf 12 January 2007, the government introduced important amendments to the energy law, articulating, in line with the provisions of the Directive 2004/8/EC, the promotion of cogeneration based on a useful heat demand in the internal energy market. Under this act, efficient cogeneration means combined production of useful electric power and heat, which allows to save the primary energy by no less than 10% in comparison to production of power and heat in distributed systems of efficiency reference value for separate production.

In the case of the extraction condensing turbine of Katowice, when the conversion indicator equals at least the boundary value, the entire production id treated as the electric energy coming from cogeneration. If the indicator is smaller, only a part of energy calculated in compliance with the regulation to be published, is treated as electric power from cogeneration.

From 6 January, the power and heat plant Katowice, in cooperation with the sales department of the management centre of PKE SA, launched the production of electric and heat energy with the most efficient conversion ratio. This method consists in forecasting demand for thermal power on the following day on the basis of available weather forecasts by the control engineer at the power plant. The control engineer prepares power unit operation chart, planning the production for each hour so as to generate the scheduled heat at maximum conversion ratio.

From our experience, we know hoe difficult it is to forecast the weather even for meteorologists; thus work preformed by control engineers is called hunting for red energy. So far, the results are satisfactory. Average conversion ratio in January was 77.7%, in February it reached the level of 81.3% and for some days it was even 86%.

Currently, electric power generated by power and heat plant Katowice is delivered and sold under a long-term contract to PSE. Activities related to achievement of the most efficient conversion ratio with the combined production of useful electric power and heat are conducive to achievement of higher efficiency ratios as well as allow to gain experience in planning and production of highly efficient cogeneration, which will yield results upon termination of long-term contracts.

At present, power and heat plant Katowice is looking forward to legal regulations pertaining the methods of settlement of combined production of useful electric power and heat from renewable sources in the process of biomass co-combustion, which will be settled in the plant from 2008 on.

Jarosław Bojda