Abstract
Cement manufacturing is one of the most energy-intensive industries in the world. Most of the cost of producing cement is accounted for in terms of fuel consumption and power expenditure. Thermal power plants are a significant contributor to electricity generation in countries such as Pakistan. They are, however, inherently inefficient, and environmentally unfriendly. In this paper, the authors investigated the possibility of delivering hybrid energy to Pakistani cement plants. Five cement plants-Askari Cement Plant, Wah (ACPW); Bestway Cement Plant, Kalar Kahar (BCPKK); Bestway Cement Plant, Farooqia (BCPF); Bestway Cement Plant, Hattar (BCPH); and DG Cement Plant, Chakwal (DGCPC)-were selected. The possibility of implementing the four off-grid hybrid energy models (HEMs) was investigated for the intended cement plants, using HOMER Pro software. A multi-criteria decision analysis (MCDA) was carried out, based on objectives including the net present cost (NPC), the levelized cost of electricity (LCOE), and greenhouse gas (GHG) emissions. HEM-1 was comprised of PV, converter, and a fuel cell. HEM-2 had only a diesel generator, and acted as a base case in this study. HEM-3 had solar panels and a battery-converter system. In HEM-4, diesel generators, PV, and converters were considered. Based on the NPC, the optimal model was HEM-4, having a 0.249 USD/KWh LCOE in islanded systems. The NPC and operating costs were USD 540 M and USD 32.5 M per year, respectively, with a 29.80% reduction in the CO2 emissions compared to the base case. Based on the GHG emission, HEM-1 and HEM-3 were the best models, with 0% GHG emissions. The results confirmed that the proposed HEMs can sustainably provide electricity for 24 h a day to the sites under consideration, with minimum objectives.