Scientific methodology and mathematical models for planning the development of the national energy sector

Bulgarian energy sector faces numerous challenges: high energy intensity of gross national product; strong dependence of energy supplies on a single supplier; insufficiently aligned with national interests structural economic reforms that do not adequately account for the complex interactions of energy – economy – technology – environment – society – security – climate – globalization – Internet of Things; significant share of the shadow economy; sufficient availability of local but highly polluting lignite energy sources; limited water resources; sufficient solar and wind primary energy, a large share of which is utilized at long-term determined "preferential" prices; low purchasing power of consumers and widespread energy poverty; high share of electricity consumption in final energy consumption; high share of electricity production through mandatory purchase; insufficiency of the regulation range of electricity generation capacities, etc.