Technical and Economic Feasibility of Achieving the Various Net-zero Energy Targets in a Bioethanol Production Plant

In this study, the feasibility of achieving the net-zero energy (NZE) target has been studied in a bioethanol production complex (Zist Faravarde Sepahan) based on different NZE definitions, including net-zero site energy, net-zero source energy, net-zero energy cost, net-zero energy emission, and net-zero exergy. In the technical investigations, the energy required for each approach has been determined, and then the corresponding photovoltaic power plant has been simulated in photovoltaic systems software (PVsyst) and transient systems simulation program (TRNSYS) by considering the generated and consumed energy. Afterward, the annual cumulative data of generation, consumption, export, and delivery energies of the complex have been extracted in the transient hourly conditions. The load matching, self-consumption, and electricity self-sufficiency indices were determined and compared in different approaches based on the hourly data. In the next step, β factor that is a fraction of the net present value (NPV) definition has been studied for the economic evaluation of the approaches in three pricing strategies: a) Buy all sell all (BASA), b) Net energy measurement (NEM) and c) Net billing (NB). Based on the technical evaluation, the net-zero energy cost approach is the most appropriate option to achieve the NZE target in the complex. Considering economic considerations, the net-zero energy cost in the BASA pricing strategy with a nominal power of 1.2 MWp < /sub> and a self-consumption index of 84.2% has the best results in both technical and economic investigations. β factor and NPV indices are 1.97 and $ 1,579,512 in this approach, respectively. The profitability phase (NPV = 0) will start after 10.1 years operation of the system.