Uģis Sarma

Efficient Use of Cogeneration and Fuel Diversification

Abstract Energy policy of the European Community is implemented by setting various goals in directives and developing support mechanisms to achieve them. However, very often these policies and legislation come into contradiction with each other, for example Directive 2009/28/EC on the promotion of the use of energy from renewable sources and Directive 2012/27/EU on energy efficiency, repealing Directive 2004/8/EC on the promotion of cogeneration based on a useful heat demand. In this paper, the authors attempt to assess the potential conflicts between policy political objectives to increase the share of high-efficiency co-generation and renewable energy sources (RES), based on the example of Riga district heating system (DHS). If a new heat source using biomass is built on the right bank of Riga DHS to increase the share of RES, the society could overpay for additional heat production capacities, such as a decrease in the loading of existing generating units, thereby contributing to an inefficient use of existing capacity. As a result, the following negative consequences may arise: 1) a decrease in primary energy savings (PES) from high-efficiency cogeneration in Riga DHS, 2) an increase in greenhouse gas (GHG) emissions in the Baltic region, 3) the worsening security situation of electricity supply in the Latvian power system, 4) an increase in the electricity market price in the Lithuanian and Latvian price areas of Nord Pool power exchange. Within the framework of the research, calculations of PES and GHG emission volumes have been performed for the existing situation and for the situation with heat source, using biomass. The effect of construction of biomass heat source on power capacity balances and Nord Pool electricity prices has been evaluated.

EFFICIENT USE OF WOOD RESOURCES ON THE POWER INDUSTRY OF LATVIA

The aim of the paper is to determine the potential of energy-efficiency in the production of the -wood resources. The beginning of the paper provides a short review of the existing situation as well as a list of main problems in wood resource usage in the power industry of Latvia. A special attention is paid to large amounts of fuelwood exports. The paper gives information on the potential of fuelwood and its distribution. The result of the research is the calculation ofpotential wood resource savings resulting from energy-efficiency increase activities in heat sources, heating mains and consumer systems, which are already run using fuelwood. As a result of energy-efficiency activities in the heat energy production process, it is possible to save up to even 4.2 million MWh of wood fuel. At the end, approximate calculations of emission savings in case of the utmost efficient wood usage have been carried out.