Environmental impacts of different electricity production mixes in Slovenia

Oskrba z električno energijo je kompleksen proces, ki zajema različne tehnologije proizvodnje električne energije in distribucijo do porabnikov. Tehnologije za proizvodnjo el. energije porabljajo različne energente in imajo zato drugačne vplive na okolje. Za oceno vplivov na okolje smo uporabili metodo študije življenjskih ciklov (LCA) in ovrednotili enajst tehnologij, ki se uporabljajo v Sloveniji, pri čemer funkcionalno enoto predstavlja 1kWh električne energije pri končnem porabniku. LCA model smo postavili v programu GaBi Thinkstep, oceno rezultatov na ravni okoljskih indikatorjev pa smo opravili po metodi ReCiPe. Najnižje vrednosti okoljskih indikatorjev imajo hidroelektrarne in vetrne elektrarne. Nizke vrednosti so še pri jedrski elektrarni, fotovoltaiki in zemeljskemu plinu. V povprečju dva do petkrat višje vrednosti so pri termoelektrarnah na lignit, črni premog, biomaso in odpadke. Najvišje vrednosti pa so bile pri težkem kurilnem olju in bioplinu. Dodatno smo analizirali okoljske vplive štirih scenarijev proizvodnje električne energije za Slovenijo, ki se nanašajo na zapiranje TEŠ-a, postavitev drugega bloka jedrske elektrarne in na prehajanje proti 100% deležu obnovljivih virov energije. Ugotovili smo, da prehod na obnovljive vire, v primerjavi z obstoječo energijsko mešanico, za polovico zniža vrednost indikatorja podnebnih sprememb, se pa močno povečajo toksičnost, evtrofikacija, zakiseljevanje, raba zemlje in tanjšanje ozonske plasti. Z drugim blokom jedrske elektrarne pa bi večina indikatorjev imela nižje vrednosti.Electricity supply is a complex process involving various technologies of electricity generation and distribution. Electricity production technologies use different energy sources and therefore have different impacts on the environment. To assess the impact on the environment, we used the life cycle study (LCA) method and evaluated eleven technologies used in Slovenia. The functional unit is set at 1kWh of electricity at the consumer. The LCA model was set up in the GaBi Thinkstep program, and the evaluation of the results based on environmental indicators was performed according to the ReCiPe methodology. Hydropower and wind power plants have the lowest values of environmental indicators. Nuclear power plants, photovoltaics and natural gas also show lower values. On average, two to five times, higher values for environmental indicators are observed for thermal power plants on lignite, hard coal, biomass, and waste. The highest values were for heavy fuel oil and biogas electricity production. We additionally analysed the environmental impacts of four scenarios of electricity production in Slovenia, which relate to the closure of thermal power plant TEŠ, the construction of the second unit of the nuclear power plant Krško and the transition to renewable resources. We found that transition to renewables, compared to the existing energy mix, halves the value of climate change indicator, but significantly increases toxicity, eutrophication, acidification, land use and ozone depletion. With the second block of the nuclear power plant, however, most indicators would have lower values