In 2022, the main renewable energy source in Slovenia originating from agriculture was biogas. Other agricultural sources of renewable energy have not yet taken off.
The development of agricultural biogas plants began in Slovenia after the government of the Republic of Slovenia defined more appropriate purchase prices and premiums for qualified electricity producers (for biogas plants) after 2002. In addition to slurry or manure, these biogas plants also use other input substrates, mostly energy plants (crops), which have a good yield of methane or biogas. After 2012, there is no longer any support for new biogas plants if they use crops as the main input substrate. This reduced the interest of investors in the construction of new biogas plants.
Before 2016, biogas plants received support by applying to the Energy Agency after their construction and meeting the conditions. With the Regulation on subsidies for electricity produced from renewable energy sources, UL RS, no. 74/2016, support for new biogas plants is awarded through tenders, where each applicant offers his price, which must not be higher than the reference price. Only the most favourable applicants are selected. This way of entering the support scheme does not encourage investors to build new biogas plants. From 2016 to 2023, there were some biogas plants accepted into the support system, but in the end no new biogas plants were built.
In the same location there can be more biogas plants. Some of these biogas plants are conditionally agricultural, as they also use substrates that do not originate from agriculture. Some of the biogas plants are no longer in operation (Ihan, Ecos Lendava). Some of them changed owners, some of them were even with the Bank Claims Management Company (DUTB).
Until the end of 2022, biogas was used only for the production of electricity and heat. The heat energy produced is partially used for the technological process of anaerobic fermentation, but the greater part is often underutilized. The use of biomethane (additionally purified biogas) as a fuel has not yet taken off in our country, although in Slovenia in 2022 we already have many vehicles that run on compressed natural gas (CNG) or biogas (biomethane). After the end of the 15-year support system, some biogas plants are seriously considering the production of biomethane, which makes it possible to enter the new support scheme.
In Slovenia, we also grow oilseed crops, among which rapeseed is important for energy purposes. Figure KM24-2 shows arable areas (surface) for the production of rapeseed for the period from 2000 to 2022. The average yield of rapeseed in Slovenia is relatively small, as it is between 1.8 and 3.6 t/ha in the considered time period, long-term average in the considered time period is 2.58 t/ha.
In Slovenia, we had a biodiesel factory "Biogoriva" within the framework of Pinus Rača. Biodiesel production there has stopped. During production, domestic and foreign plant oil was used. The raw material grown at home in Slovenia - rapeseed was pressed years ago in the domestic oil mill BIEL in Brežice. However, this oil mill has closed. In Slovenia, there are still a few small oil mills (micro oil mills) on family farms for pressing rapeseed oil, but the oil obtained there is not intended for sale for the production of biodiesel. Due to price conditions, a lot of rapeseed is exported abroad. The further use of this seed abroad is not known, it is possible to obtain oil for food as well as for energy purposes. The use of pure plant oil obtained from rapeseed as fuel for driving diesel vehicles represents an insignificant share in Slovenia. In principle, the country of Slovenia supports the use of biofuels. Pure biodiesel is completely exempt from excise duty, while mixtures of biodiesel and gas oil (diesel fuel) are partially exempt. Pure plant oil as an energy source (fuel) is an excise product for which excise duty must be paid, which then reduces its competitiveness with diesel fuel in the final price. In principle, fuel distributors mix up to 7% of biodiesel into regular diesel fuel. In the case of too expensive biodiesel, they also pay penalties for not mixing the mandatory share.
In Slovenia, until 2011, we did not cultivate energy crops for the production of bioethanol. Likewise, we do not have cultivation on agricultural land - the cultivation of non-forest plantations of fast-growing tree and shrub species. By-products from crop production, such as grain straw, are not used for energy purposes. The use of corn cobs as a source of energy in biomass stoves is collected in a mechanized way with an adapted combine harvester for harvesting corn kernels on only one family farm.
In recent years, attempts have also been made to introduce agrophotovoltaics in Slovenia. This is photovoltaics on agricultural land. Most photovoltaics in Slovenia are installed on roofs, there are also some free-standing photovoltaics on land for which it was necessary to change the purpose to building land. In principle, the Ministry of Agriculture, Forestry and Food supports agrovoltaics in permanent plantations or in greenhouses. In practice, agrophotovoltaics do not yet exist in our country.
The European Common context indicators for rural development programs (2014-2020) contain indicator CCI 43 - Production of renewable energy from agriculture and forestry. It shows data for 2018 on the production of renewable energy sources from agriculture, data on the production of renewable energy sources from forestry and data on the total production of renewable energy sources for the EC 27 and particular member states. Germany has the largest production of renewable energy from agriculture, namely 10,358 kToe. France and Italy follow with 3,660 and 2,218 kToe. The entire EU27 has a production of 26,385 kToe from agriculture, which represents a 12% share among all renewable energy sources.