12th International Symposium on District Heating and Cooling

The <strong>12th</strong> <strong>International</strong> <strong>Symposium</strong> on District Heating and Cooling,September 5 th to September 7 th , 2010, Tallinn, EstoniaCHP OR POWER STATION? – QUESTION FOR LATVIAD. Blumberga 1 , G. Kuplais 1 , F. Romagnoli 1 and E. Vigants 11 Riga Technical University – Institute of Energy Systems and EnvironmentKronvalda boulv. 1, LV-1010 – Riga, LatviaABSTRACTThis paper presents aspects and problems of theLatvian energy-system connected to the choice of theCHP and/or power stations for the future nationalenergy strategies. In the light of the last EU directive inthe subjects of Renewable Energy Sources (RES) theshare of electricity produced from RES at the momentis attested on the value of 42.4 % but should beincrease to 49.3%. In the same time the share ofrenewable energy resources in the final energyconsumption for 2020 should reach the level of 40%from 30%.Dependence on imported energy sources, growth ofelectricity prices, the need to support local producersare the main reasons for the use of new renewableenergy technologies in the Latvian energy sector toimplemented in refurbished energy supply system.Several methods fro the evaluation of the best strategyare explained.This apaper summarizes the application of the EnergyIndicators for Sustainable Development (EISD) as goodtool for analyzing trends, setting energy policy goalsand monitoring progress. The results from theapplication of a multi-objective optimization regardingthe implementation of the landfill biogas in the biogastreatement plant ―Daibe‖ are reported.1. INTRODUCTIONThe structure of energy user in Latvia is characterizedby high energy consumption in households, public andservice sectors, comparing with relatively lowconsumption in rural and industrial sector. In light ofthis situation, for the power sector development,special tasks are required in connection to the choiceof the more adequate energy resources in order toensure the best energy production and supply.Consequently question on which direction address themain efforts for the energetic national improvement isstill actual: CHP or Power station?If fuel, which is used to produce heat and electricalenergy in Latvia, is taken into account, the dominantone is gas [1] and consequently appear evident howthe Latvian dependence on foreigner energy supplies(mainly from Russian) is not only a weak point inconnection to the energetic sustainability but can serveas a convenient way of exerting economic pressure [2].In CHP station this dominance is almost total and veryhigh in district heat supply boiler houses. As it wellknown Latvia is a great consumer of imported fossilfrom one side but in the same the share of renewableenergy resources is one of the highest of Europe.The use of specific energy resource depends onenergy supply policy, and total consumption of energyresources depends on development of every type ofenergy resources in regions. Now there is unjustifiedhigh proportion of fossil fuel in state energy balancewhich is possible to reduce by a beginning of activeuse of local fuel in regions. The EU directive alsorequires that Latvia in the year 2015 would generate49% of electric power from renewable resources(currently it is 45%) [3]. This is supportable, but thepower supply of Latvia cannot be let out of the sightand this issue is already problematic.Latvia has some electricity production from cogenerationplants and some from hydro-power plants.However, the production of electricity from the hydropowerplants fluctuates a great deal from year-to-year.The rest of the electricity for consumption is importedfrom the neighbouring countries.In order to understand the role played by CHP andpower plant it is fundamental to understand the actualsituation in Latvia for thermal energy where more thana half of Latvia district thermal energy is distributed andconsumed mainly in Riga.Latvian heating primarily is performed on a centralizedbasis and after the used of wood energy the naturalgas imported from Russia is the main source (seeFig. 1).Fig. 1. Main resources used for local and individual heatsupply [3]177