City municipality of Koper is the largest City municipality by area in Slovenia. It is one of the best developed municipalities due to the large international Port of Koper. The main city – Koper – is the fifth largest city in Slovenia with a population of just over 23000. The dense old medieval town, protected as cultural heritage, was built on an island which was later connected with the mainland through land reclamation. The reclaimed land is now mostly built up with commercial, industrial, and port areas on the east and recreation and residential areas on the south and west. Beyond the commercial outskirt of the city is a lagoon protected as a natural reserve. The hinterland of the city is hilly with dispersed settlements, small villages, and intense agriculture, often in the form of vineyards, where natural conditions are favourable.

With no intermediate governance level between national and local scale, municipalities in Slovenia are required to create their own local energy concepts. Koper’s local energy concept recognizes solar as renewable source with great potential and even proposes several municipal pilot installations of PV or heat collectors on publicly owned buildings. There are also some PV installations (up to 500 kW) on commercial buildings. There are 29 solar power plants that are included in the national support scheme with installed capacity of 3,14 MW, producing 1785 MWh annually.