The main strategic goals of the European Union (EU) and Slovenian energy strategies are the reduction of the emissions of greenhouses gases, an increase of the share of electricity production from renewable energy sources (RES) and a decrease of energy dependency. The overall targets of the EU climate and energy package, known as “20-20-20”, are a 20% increase in energy efficiency, a 20% reduction in greenhouse gas (GHG) emissions, a 20% share of renewable energy sources in overall EU final energy consumption, and a 10% share of renewable energy sources in transport by 2020. Individual targets for each Member State have to be determined as fairly as possible. The obligation of Slovenia is to increase the share of RES in final energy consumption from 15.1% in 2005 to 25% in 2020. Another obligation of Slovenia is to increase the share of electricity production from RES to 33.6% of the 2010 level total electricity consumption. The priority to increase the share of RES in the energy supplies in the EU-27 has continued more intensively to avoid the rapid impacts on environment (climate change) and to increase the security and sustainability of energy supply. In 2008, the share of renewable energy in primary energy was less than 11%, and it was 15.1% in gross final energy consumption. The share of electricity production from renewable energy sources represents 30% of gross electricity consumption in Slovenia. The development of renewable energy sources in Slovenia as well as an analysis of the Slovenian energy policy will be presented in this paper. Special focus will be given to the actual programs (RES action plan) and the potential of future development.
COBISS.SI-ID: 25512487
Production of pure plant oils for fuels or biodiesel production now is based on the extraction of oil with mechanical extraction of seeds or by using solvents (organic solvents used in large industrial plants). Mechanical extrusion of seeds is carried out by continuous mechanical screw type presses. To determine the energy consumption and CO2 emissions in the decentralized production of oil we used mechanical screw press, which is designed for the extraction of oil by mechanical compression of various oil seeds. The machine performs continuous cold extraction of oil seeds (process does not need warming of oil seeds or single machine). We found that in single phase pressing of rape seeds, energy consumption is from 7.2 to 10.1 kWh/t of processed seeds (decentralized production of oil consumes significantly less energy than the production on industrial level). In the second stage of pressing, energy consumption is from 7,1 to 8,1 kWh /t of processed oil seeds. The sum of the first and second stage of pressing, gives energy for the two phase pressing. In mentioned case energy consumption is in range from 14,3 to 18,2 kWh /t of processed seeds. CO2 emissions from decentralized pure plant oil production, are also low, in range from 2,592 to 3,924 g CO2/kg oil at first stage of pressing. Due to the better efficiency of process, applied was two phase pressing, so that the total CO2 emissions (sum of the first and second phase) ranging from 5,148 to 6,84 g CO2/kg oil.
COBISS.SI-ID: 4079464
An analysis of the carbon footprint of conventional, integrated and organic crop production, and three sizes of farms was made. Conventional tillage and direct seeding were used in mentioned production systems. For the analysis of the carbon footprint, CO2 emissions from fossil fuel (direct energy) consumed in the process of production of corn (for silage and grain), wheat, rapeseed, and sunflower were used. In addition to emissions from fossil fuels used in the production of mentioned crops, greenhouse gas emissions resulting from the use of organic and mineral fertilizers in the production and converted to CO2 equivalents were also used. In the case of conventional production mineral fertilizers were used, in integrated production combination of mineral fertilizers and organic fertilizers and in organic production only organic fertilizer was used. The sum of emissions arising from fossil fuel use and emissions from fertilizers used in the cultivation process, make final emission from crop production. It was estimated that the emissions of CO2/t of yields in conventional and integrated production are about the same. In organic production emissions of CO2/t of yields are higher in comparison with emissions CO2/t of yields in conventional and integrated farming. CO2 emissions in conventional and organic production (CO2/t of yield) are in the following proportions: corn for grain 1:1,34, corn for silage 1:1,52, wheat 1:1,53, rapeseed 1:1,47 and sunflower 1:1.2 (the higher is the number of organic production).
COBISS.SI-ID: 4419688
Development of utilization of renewable energy sources and energy efficiency presents a main policy for sustainable development. The overall target of the EU Directive on the promotion of the use of energy from renewables (RES) is to achieve at least a 20% share of energy from renewables in gross final energy consumption in 2020. The mandatory national target for Slovenia is 25% share of energy from RES in gross final consumption. The Slovenian Government according to this Directive approved a “National Renewable Energy Action Plan 2010-2020” and adopted a new Decree on support for electricity generated from RES and in high-efficiency CHP. The share of RES in gross final energy consumption in Slovenia was 18.8% in 2011 and the share of electricity production from RES was 30.8% in gross electricity consumption. The electricity production in photovoltaics (PV) and biogas plants in agriculture has been growing fast after the adoption of the new supportive decree for electricity from RES in 2009. The too fast growth of PV plants is causing a problem for financing of electricity from RES and in high-efficiency CHP. Fast growth occured also in electricity from biogas plants using agricultural production, which presents a threat to food production. State of the art, targets and challenges of electricity production from RES in Slovenia will be described in the paper.
COBISS.SI-ID: 27133479
Currently in Slovenia, all biogas on agricultural biogas plants is used in cogeneration units for the production of electricity and heat, but only a small number of biogas plants distribute heat energy to other end users (because of technical and economic barriers), therefore the efficiency of cogeneration is relatively low. Biogas is relatively easy to store and can then be used anywhere and at any time. The possibility of storage of biogas represents its specific value (with storage and its use it is possible to compensate fluctuations, which have other renewable energy sources, such as wind and solar energy). Biogas offers us another possibility, for example, cleaning and its upgrading to phase of biomethane. With the injection of biomethane in the future it will be possible to take advantage of the existing network of natural gas and the gas can be transported over long distances, which will be accessible to users which are not achievable due to its location. With the injection of biomethane into the natural gas network will be possible to improve efficiency of existing agricultural and other biogas plants. By cleaning the biogas and upgrading to biomethane phase also will increase the number of potential biogas users. A review of potential technologies that will enable better use of biogas in the future is presented. Included are technologies for micro and other biogas plants and the potential for the introduction of biomethane technology in Slovenia.
COBISS.SI-ID: 4236136