Multi-objective optimization of a building integrated energy system and assessing the effectiveness of supportive energy policies in Iran

In the present study, a building-integrated energy system with the potential of providing electricity, heating, and cooling is investigated via energy, exergy, and economic analyses. A case study is considered, and two scenarios of meeting the loads for these cases are introduced. The heating, cooling, and electrical loads of a secondary school building are modeled annually. In addition, net present value (NPV) is considered as an effective method of obtaining the proposed energy system's economic aspect. Results show that; supportive programs are not effective for promoting solar energy due to low fuel cost under the current condition. The exciting result is that subsidy removal for natural gas fuel does not increase the solar share and even makes the energy efficiency options like combined heating and power (CHP) less attractive. In addition, a comprehensive exergetic and exergoeconomic analysis are carried out for the best-case scenario plant. The outcomes demonstrate that the combustion chamber owns the largest exergy destruction. Moreover, the exergy and energy efficiency of the overall system is 58% and 76%, respectively. Multi-objective results show that at the best solution point, the system has an exergy efficiency of 61% and a unit product cost of 13.75 $/GJ.