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

The indicator can be shown in relative (share of renewable energy sources) or absolute units (use of renewable energy sources). For the indication in absolute units, a thousand tonnes of oil equivalent (ktoe) are used.

The use of renewable energy sources (RES) in 2013 amounted to 1,129 ktoe, which was 9.2% more than a year earlier (Figure EN 18-1). The highest share was taken by wood and other solid biomass (50.6%); the second most important source was hydropower (35.1%). The shares of other sources were as follows: liquid biofuels 5.3%, geothermal energy 3.4%, biogas 3.1% and solar energy 2.5%.

Given its large forested area (58.4% in 2011 according to the Slovenia Forest Service, 2012), 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. In 2013, wood represented 99% of the use of solid biomass. Most solid biomass is used in households (472 ktoe in 2013), followed by industry (48 ktoe) and transformation (45 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. In 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. In the period 2002–2008, use of biomass was constant. On the basis of a survey on energy consumption in households, a model was developed in 2009, which has now been used annually to estimate the use of wood biomass. 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. 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. In 2013, use increased by 19%; however, it was still 27% below the 2000 value. In the field of transformation, the use of wood biomass increased. In 2001 it was 121% higher than in 2000. It increased significantly in 2008 when the large TEŠ, TET and TE-TOL thermal power plants started using wood. In the period 2009–2013, the TE-TOL plant was the only larger thermal power plant that still used wood. The use of wood in district heating is increasing as well since the number of smaller wood biomass systems has been growing due to the incentives provided by the ministry responsible for energy.

The second most important renewable energy source in Slovenia is hydropower. Electricity generated from hydropower amounted to 4,613 GWh (excluding pumped storage hydroelectric power plants) in 2013, which was 18.5% more than a year earlier. Generating capacity increased by 30% in the period 2000–2013 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 projects to exploit hydro potential are also being prepared, including: an HPP on the middle Sava, an HPP on the Mura, etc. Electricity generation in HPP is largely influenced by hydrology, which has been worse than average in recent years. In 2013, hydrologic conditions were favourable. The utilisation period of maximum demand was 4,122 h, which was 7% above the average for the last 15 years.

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 use of liquid biofuels in transport appeared in 2006 for the first time and increased until 2010. In 2011, use decreased by 20.7%. Growth resumed in 2012 and 2013, reaching 15.6% in 2013. 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. In 2013, the use of solar energy (thermal solar collectors) was 3% higher than a year earlier. The use of electricity generation in solar power plants has also been increasing (a 32% increase compared to 2012). Total use of geothermal energy increased by 11% in 2013, largely as a result of growth in the number of heat pumps.

The consumption of renewable energy sources in 2013 represented 16.6% of total energy consumption. Thus, the 12% goal set for 2010 was surpassed, which happened in 2009. 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 2013, the share of biofuels in the structure of fuels used in transport increased by 3.1% compared to the preceding year. This was considerably below the target share for that year (6.5%). The shares notably below the target values were also observed in earlier years. Cancellation of an exemption from excise duty on biofuels, which was introduced in 2014, made meeting the goals even more difficult.

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, is 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).