In Slovakia, biomass represents the third-best potential renewable source of energy. Slovenské elektrárne reacted to this trend in summer 2009, since when the biomass co-combustion project at the Vojany Thermal Power Plant was implemented.
What is biomass?
Biomass is the complex of materials that make up the bodies of all living organisms, i.e. plants, bacteria, cyanobacteria, algae, fungi, mosses and Bryophytes, as well as animals. We often use this term to mean plant biomass usable for energy. The energy of biomass has its origin in solar radiation and photosynthesis, and is therefore a renewable source of energy. In Vojany, the co-combusted biomass is in form of woodchips.
What have we achieved?
In the Vojany Thermal Power Plant, the co-combustion of a 10-percent share of woodchip biomass was launched in summer 2009, representing 4 percent of thermal energy input. It thus saved 7,239 tonnes of CO2 in emissions in just the period to the end of that year. The original project counted on saving 21,000 tonnes of carbon dioxide emissions annually when co-combusting woodchips and black coal in fluid boilers. However, in one year of co-combusting biomass (July 2009 - July 2010, i.e. 13 months), 19,145 tonnes of woodchips were combusted, which in the end saved as many as 23,250 tonnes of CO2.
Why was biomass chosen?
When combusting it, only the CO2 which the plant absorbed during its existence is emitted into the air. Moreover, the increased demand for biological materials suitable for production of biomass can give a new impetus to agriculture. Woody plants suitable for this use are among the least demanding, so growers will be able to plant them even on soil which could not previously have been used. For the wood-processing and forestry industries it is an advantage to be able to dispose of wood cut offs which can otherwise only be processed into wooden pellets. The technological potential of biomass is 163 PJ. By comparison, the second-best prospective source, solar energy, has only 35 PJ. However, biomass' current share of the energy mix of Slovakia is only 2 percent. Thanks to projects like that at the Vojany power plant, Slovakia can gradually come closer to the 4-percent use of biomass which is the average in European Union member countries. Thanks to the efforts of Slovenské elektrárne, the share of biomass in the energy mix of the Slovak Republic has thus been doubled.
