The intensive global increase in energy needs, as well as the impact it has on the environment and society as a whole, leads to the need for a longer-term consideration and reconsideration of attitudes towards fossil and non-renewable energy sources. Solar energy is a renewable and unlimited source of energy that in its original form is most often used for the production of thermal energy in domestic hot water and heating systems and in the production of electricity using photovoltaic cells. Favorable insolation and climatic conditions of the City of Zagreb guarantee great technical potential. About 3.5 kWh of solar energy per day falls on 1 m² of horizontal soil of the Zagreb region, which is about 20% more than in northern or central Europe.

By investing in solar panels for water heating, the City of Zagreb creates a real opportunity and an example of how to produce energy and save the environment from further pollution. Successful implementation of this project will reduce energy needs for water heating in public buildings by about 65%.

The Photovoltaic System for Electricity is built on a total of 10 facilities, namely 5 city government buildings, 4 primary schools and 1 kindergarten. Projects for other 22 buildings owned by the City of Zagreb were drafted. Additionally, solar panles are installed in a total of 35 facilities, 24 kindergartens, 4 adiministrative facilities, 5 retirement homes, and 2 helth care centers. As part of this project, technical paperwaork has been prepared to extend the installtion to another 38 facilities.

The installation of a system of renewable energy sources will save 1,200,000 kWh of energy, and the expected reduction in greenhouse gas emissions is 330 t.