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Kogu maailma majandus sõltub tänapäeval naftast ehk maaõlist, mida kasutatakse muuhulgas soojuse tootmiseks. Kuigi naftavarude reserve veel on, muutub nafta kättesaamine keerulisematest kohtadest majanduslikult ebaotstarbekaks ning ühel hetkel on oluline fossiilkütuste kõrval ka teiste energiaallikate olemasolu, näiteks ühe võimalusena – bioenergia kasutamine. Bioenergia all peetakse silmas biokütuste muundamisel saadud energiat, kus energiaallikana kasutatakse orgaanilise ainet. Kuna bioenergia valdkonda kuuluvatest energiaallikatest on perspektiivsed kõik puitkütused, siis on Eestil suur potentsiaal tänu ulatuslikele metsavaldustele biomassi kasutamisel energiaallikana soojamajanduses. Käesoleva bakalaureusetöö eesmärgiks on anda ülevaade bioenergeetiliste ressursside mahu ja kasutamise kohta Põlvamaa soojamajanduses. Eesmärgi täitmiseks seadis autor uurimisülesandena anda ülevaade Põlvamaa küttepuidu ressursist ning selle kasutamisest biokütuse tootmisel ning analüüsida Põlvamaal vallavalitsuste lõikes kasutatavaid soojamajandamise põhimõtteid ja biokütuse kasutamisepraktikaid, samuti analüüsida Põlvamaal biokütustel töötavate katlamajade tehnoloogilist lahendust ja biokütuste kasutamispraktikat; tuua välja tulemused ja autoripoolsed ettepanekud seoses küttepuidu kasutamisel bioküttena. Empiiriliste andmete kogumiseks kasutas autor küsitluse meetodit ning andmekogumise instrumendiks olid lahtiste küsimustega ankeedid, samuti kogus autor teavet intervjuudega, küsitledes ettevõtete juhte ja spetsialiste. Vallavalitsuste küsitluse valimiks moodustusid kõik Põlvamaa vallad, mida on kokku 13. Töö käigus püstitas autor eesmärgi tutvuda ka isiklikult kahe soojaettevõttega, kes kasutavad sooja tootmiseks biokütust, et mõista miks katlad läksid üle kohaliku kütuse kasutamisele. Eestis nähakse hetkel tendentsina kütuste kasutamise energia (elekter, soojus) vähenemist. Seetõttu on oluline keskkonnasäästliku ja jätkusuutliku energeetika arengu raames tulevikus võtta kasutusele üha laialdasemat taastuvad energiavarud. Neist kõikidest on üks olulisemaid puitkütus. Läbiviidud uuringutest selgus, et aktiviseerunud on puitkütuste katlamajade rajamine ja vanade fossiilkütuste katlamajade üleviimine tahkele puitkütustele. Kui võrrelda puidu hinna konkurentsivõimet nafta hinnaga, siis eelkõige sõltub see nafta hinna tasemest, sest puidu hind on palju stabiilsem. Põlvamaa näitel puitkütuse kasutuselevõtuks sobiva tehnoloogia valikul tuleb lähtutakse eelkõige kasutatavatest kütuse liikidest (hakkpuit, halupuit, briketid, pelletid ) erinevate vallavalitsuste lõikes. Kui aga katlamajad viiakse üle puidukütustele, siis suurendatakse puitkütuste nõudluse kasvu, mis omakorda aitab kaasa puitkütuste varumise suurenemisele. Varutava puitkütuste koguste suurenemine omakorda tekitab juurde töökohti ja aitab kaasa majanduse kasvule. The economy of the entire world is nowadays dependent on petroleum, which is among other things used for heat production. Although oil reserves are still available, obtaining oil will become economically impractical, and at one point the presence and use of other fuel sources, for example bioenergy, will become important. Bioenergy refers to the energy obtained through the conversion of biofuels, where the energy source is organic material. Since all fuelwoods that are part of the bioenergy sector are promising, then thanks to its large forest resources, Estonia has great potential to use biomass in the heating sector. In the past few decades, the forested area has doubled due to the reforestation of abandoned arable land. The aim of this thesis was to give an overview of the quantity and usage of bioenergy resources in the heating sector of Põlva County. In order to meet the aim, the author set the following research objectives: to explain the concept of bioenergy and the use of biofuel on the basis of various theoretical aspects; identify the theoretical advantages of biofuels compared to fossil fuels; give an overview of the wood resources and their usage for biofuel production in Põlva County; give an overview of the principles of the Põlva municipalities and the practices of using biofuel; analyse the technological solutions of heating plants that use biofuels and biofuel usage practices; identify the positive changes brought upon from transitioning heating plants in Põlva to using solid biofuels; and present the results and give author's proposals regarding the use of wood as a biofuel. The empirical data collection was done by using a survey method that included open-ended questionnaires and interviews that were conducted with business leaders and specilists. Municipality surveys were conducted in all of the 13 parishes of Põlva County. Answers were obtained from 5 parishes, which resulted in a response rate of 39%. In the course of the work, the author also set an objective to personally get to know two heat production companies that use biofuel for heat production, to understand why the heat plants have switched to using local fuels. The study found that there has been an increasing trend in the number of heat plants using biofuels. As was demonstrated by Statistics Estonia data, over the past five years, the largest amount of heat plants work on fuelwood, but there are also heat plants that use peat and herbal biomass. Fuelwood is mostly used for heat production, meaning that using wood and wood waste is one way of replacing fossil fuels with biofuels. Wood fuels that are used in Estonia consist mostly of firewood and to a lesser extent of wood briquette and wood pellets. The latter of those mentioned, are also exported out of the country in large quantities. Fuelwood is made up of firewood, wood chips and wood waste. When considering the role of fuelwood consumption compared to production, then it turns out that the production and consumption of fuelwood are in balance, and this trend has lasted for at least the past five years. Unfortunately, both in Estonia and in the rural municipalities of Põlva County, the energy use in the heating sector is expected to decline. Therefore, for environmentally friendly and sustainable development, it is important to use renewable energy resources more widely, in order to cut costs. Woodfuel is one of the most important one of these. The studies conducted revealed that the construction of woodfuel heat plants has increased, and that also the old fossil fuel heat plants are transitioning to using solid fuelwood. When comparing the competitiveness of timber price with oil price then in particular, it depends on the level of oil prices, as the price of timber is much more stable. From the example of Põlva County, it can be seen that the choice of appropriate technology for fuelwood should be based first and foremost on the fuel type (wood chips, firewood, briquettes, pellets) in the different rural municipalities, and if biofuel has been introduced, then this is because on the whole, the new fuel is cheaper (although the initial investments are high). The heating capacity of wood is mostly dependent on moisture, to a lesser extent on wood ash content and to some extent on the type of timber, and therefore, heating plants consider fuelwood quality as most important. Unfortunately, fuelwood prices have been rising almost continuously until 2014. The data regarding fuelwood price developments from the Statistics Estonia shows that the average annual increase in the price of firewood has been considerably slower than the price increases of wood chips and wood waste. But when gas and shale oil prices have been volatile, while having an upward trend, the price of wood chips has been more stable. Small network areas that use shale oil and natural gas, have a higher heating price cap. In almost all such regions, the price for heating is between 65-91 €/MWh, whereas in all of the the networks that use wood chips and peat, the price of heating is below 65 €/MWh. A similar trend is also visible in large networks across regions, where in the majority of cases, the networks using shale oil and gas for heat production have a price cap in the range of 65-75 €/MWh, whereas in most regions that use wood chips the price cap is between 45- 55 €/MWh. The main unused resource is logging waste, but its use for fuel manufacturing is not very economically viable at current prices. Despite that, there are companies in Estonia that add value to logging waste by producing fuels and use them for heat production. The entry of additional quantities of firewood into the market could occur if fuelwood production was backed by certain tax concessions or direct payments, which is currently not done much. In addition to environmental sustainability, the transitioning of heat plants to fuelwood use helps to increase the rate of fuelwood collection. The increased collection of fuelwood in turn creates jobs and also contributes to economic growth. |
