With its own, sustainability-oriented electricity production and effective trading, the GEN Group provides its customers with a reliable and competitive power supply. As much as 99 percent of the GEN Group's electricity output is generated from sustainable and renewable energy sources: nuclear, hydro and solar energy. This makes for a substantial contribution towards low- or zero-carbon electricity production and to the sustainable development of Slovenia. GEN energija d.o.o., is the parent company of the GEN Group and is wholly owned by the state. Its principal activity is that of holding companies. Apart from the parent company, the GEN Group also comprises the following affiliated companies: • Nuklearna elektrarna Krško, d.o.o. (NEK) • GEN-I, trgovanje in prodaja električne energije, d.o.o. (GEN-I) • Savske elektrarne Ljubljana, d.o.o. (SEL) • Termoelektrarna Brestanica, d.o.o. (TEB) • Hidroelektrarne na spodnji Savi, d.o.o. (HESS) • Srednjesavske elektrarne, d.o.o. (SRESA) With all its constituent companies, the GEN Group annually produces between 5,600 and 6,300 GWh of electricity, accounting for approximately 40-45% of all the electricity generated in Slovenia.