This indicator shows the consumption of renewable energy sources in Slovenia, which includes the use of solar energy, biomass (wood, biogas, biofuels) and waste, geothermal energy, hydropower and wind energy.

The indicator can be presented in relative (the share of renewable energy sources) or absolute terms (the use of renewable energy sources). For the presentation in absolute terms, the unit of thousand tonnes of oil equivalent (ktoe) is used.

The use of renewable energy sources (RES) in 2015 amounted to 1,056 ktoe, which was 12.2% more than a year earlier. The highest share was taken by wood and other solid biomass (55.9%); the second most important source was hydropower (35.0%). The shares of other sources were as follows: liquid biofuels 2.9%, geothermal energy 4.1%, solar energy 3.3% and biogas 2.8% (Figure EN 18-1).

Given its large forested area (58.3% in 2015 according to the Slovenia Forest Service, 2016), extensive use of wood biomass in Slovenia is expected and rational. Besides wood, solid biomass encompasses bone meal and fats, paper sludge and digestate used in industry; however they share is only 1%. Most solid biomass is used in households (463 ktoe in 2015), followed by industry (68 ktoe) and transformation (52 ktoe). The Statistical Office of the Republic of Slovenia does not monitor the use of wood biomass in services and agriculture (jointly referred to as ‘other use’), which makes its use in Slovenia underestimated. Since 2009, its use in households increased markedly with regard to the preceding years. This increase was largely a consequence of improved methodology for monitoring the use of wood biomass in households. From 2009 onwards, the use of wood biomass in households has been increasing, which can be attributed to a variety of factors: higher prices of fuel oil, economic crisis, promotion of purchase of wood burning boilers and a high percentage of forest owners among Slovenian residents. In addition, the use of biomass is influenced by the severity of winters. The winter in 2014 was very warm – as a result, the use of firewood was considerably lower than in 2013 and 2015. The use of biomass in industry has been declining since 2005. The main reason for this decline is the shutting down of the Vipap cellulose plant and the decline of the wood processing industry. From 2012 onwards, the use has been increasing again and in 2015 it was comparable to that in 2000. In the field of transformation, the use of wood biomass increased considerably when the large TEŠ, TET and TE-TOL thermal power plants started using wood. In 2015, it was 158% above the values in 2000. The use of wood in district heating has been increasing as well due to the incentives provided by the Ministry responsible for energy. Consequently, the number of small systems ussing biomass has been increasing.

The second most important renewable energy source in Slovenia is hydropower. Electricity generated from hydropower amounted to 3,080 GWh (excluding pumped storage hydroelectric power plants) in 2015, which was 37.5% less than a year earlier. The reduced generation was a consequence of unfavourable hydrological conditions. Generating capacity increased by 30% in the period 2000–2015 due to the renovation of large hydroelectric power plants (HPP Boštanj, HPP Blanca, HPP Krško) as well as the construction and renovation of small hydroelectric power plants. By 2019, the construction of the last two in the chain of six hydroelectric power plants on the lower Sava is planned to be completed. The total amount of electricity generated by five HPPs (excluding HPP Vrhovo, which was constructed in 1993) will be 720 GWh.

Other renewable energy sources used in Slovenia are as follows: biogas (landfill gas, gas from water treatment plants and other biogases – biogas systems in agriculture), geothermal energy, solar energy and liquid biofuels. The use of biogas increased by 951% over the period 2000–2012. The growth was particularly high after 2008. In 2013, the use of biogas decreased for the first time (by 8.9%), which can be attributed to stricter regulations regarding the use of input substrates. The decreasing trend continued in 2014 and 2015. The use of liquid biofuels in transport appeared in 2006 for the first time and increased until 2013. In recent years, the use of liquid biofuels has been declining. The use of geothermal (heat pumps) and solar energy (thermal solar collectors) in households appeared in the statistics for the first time in 2009, with direct use of geothermal energy in health resorts and agriculture following in 2010. The statistics also follow electricity generation in solar power plants. The use of solar energy (thermal solar collectors) is increasing slowly. Electricity generation in solar power plants has also been increasing. However, the increase has slowed considerably down over the last couple of years due to changes in  the subsidy scheme. Total use of geothermal energy is increasing as well, which is largely as a result of growth in the number of heat pumps. Total use of other RES increased by 22% in the period 2010—2015.

The consumption of renewable energy sources in 2015 represented 16.4% of total energy consumption. Thus, the 12% goal set for 2010 was surpassed. Meeting the goal was not only a result of the increased use of renewable energy sources and the improved monitoring of their use by the statistics, it was also greatly influenced by the reduction in total energy consumption as a result of the economic crisis and the implementation of energy efficiency measures (for more information, see indicators EN16 Total energy consumption by fuel and EN10 Final energy consumption by sector).

In Slovenia, the use of renewable energy sources is encouraged through various mechanisms. Investments in new devices are stimulated by the Environmental Fund of the Republic of Slovenia through favourable loans and subsidies, which are also provided to final customers by large taxpayers pursuant to the Decree on energy savings requirements. The use of wood biomass and geothermal energy in district heating systems is stimulated by the ministry responsible for energy. Electricity generation from RES is promoted by the support scheme for electricity production from renewable energy sources (for more information see indicator EN19 Electricity production from renewable energy sources). The use of biofuels is encouraged by excise tax exemption which, however, has only been available for 100% biofuels (and not for blends) since 2014. Also, distributers of liquid motor fuels must meet goals defined by the Decree on the promotion of the use of biofuels and other renewable fuels for the propulsion of motor vehicles (Official Gazette of the Republic of Slovenia, no. 103/07). In order to promote the use of renewable energy sources and meet the target share of RES in gross final energy consumption, the Renewable Energy Action plan was adopted in 2010 (for more information, see indicator EN24 The share of renewables in final energy consumption).