engleski

Optimization of energy supply in the public buildings: the Case of a primary school in the City of Koprivnica

Over a third of world’s energy consumption comes from residential and commercial buildings. The consumption of energy in buildings can be decreased by increasing their thermal efficiency. By increasing the thermal efficiency of a building we not only lower the utility cost but we can also increase thermal comfort and most importantly reduce CO2 emissions. Further decrease in CO2 emissions can be made by supplying energy for buildings from renewable energy sources. On today's market there are a good number of solutions to provide heating, cooling and even electrical energy for buildings. In order to choose the most economically feasible solution a mathematical model utilizing linear programming was developed. The model takes account of various options and calculates which of them provides energy at the lowest cost taking in consideration available renewable energy sources such as wind and solar as well as building insolation and fixed and variable costs of a given solution. A decent percentage of public buildings in Croatia were built before 1990. The attempts to increase their energy efficiency have mostly been focused on improving their outer envelope. If there is an attempt at improving their energy supply solution it is usually based on conventional energy sources. To show that when increasing energy efficiency of a building both the outer envelope and the energy source should be taken into account the model was applied on an elementary school in northwest Croatia. The school’s building was built in the beginning of the twentieth century which makes it a good candidate for a renovation project. Since applying the model to this school was used as a validation case a sensitivity analysis was performed to see how the change of variable costs affects certain solutions.

Optimisation of Energy Supply; Renewable technologies; Linear programming; Net present value

nije evidentirano