Design and regional analysis of a renewable energy-supported microgrid: a publi̇c building example

A significant portion of the electricity produced today is derived from fossil fuels. Electricity generation from fossil fuels contributes to air pollution, global warming, and the resulting effects of climate change, there by harming the ecological system. The decreasing lifespan and eventual depletion of fossil fuels, coupled with the inexhaustible nature of renewable energy sources, have made renewable energy increasingly popular. However, to address the intermittency issues inherent in renewable energy sources, hybrid renewable energy systems capable of operating in both grid-connected and islanded modes are utilized. Over the life cycle of public buildings, energy consumption constitutes one of the largest cost components. Improvements in energy usage can significantly reduce life cycle costs, there by making substantial contributions to the national economy. In this study, the energy demand of the Bursa Metropolitan Municipality Additional Service Building, located in Bursa and currently supplied by conventional energy sources via the interconnected grid, was analyzed with the aim of meeting this demand using hybrid renewable energy sources. The study focused on determining the most suitable hybrid power generation system by considering the potentials of existing energy resources. Initially, the real-time electricity consumption of the public building was determined through its Automatic Meter Reading System (AMRS), and the load profile of the building was prepared. The building was modeled in three dimensions using the SketchUp software, and optimal placements of photovoltaic (PV) panels were determined using the Skelion software, considering shading and performance analyses. Simulation, optimization, and sensitivity analyses of the hybrid energy systems designed in this study were performed using HOMER software. First, scenarios where energy sales to the grid were not allowed, and only self-consumption was considered were analyzed. Second, scenarios where surplus energy was sold to the grid, essentially evaluating net metering, were analyzed along with scenarios of monthly and annual net metering for similar public buildings located in different geographical regions. Third, comprehensive analyses were conducted on meeting the energy demand of the public building with hybrid renewable energy sources in scenarios where electric vehicle charging stations were integrated into the building's load profile. In the studies conducted, considering that the purchase price of 1 kWh of electricity from the distribution company is $0.127, it was calculated that the unit price of electricity in public buildings where energy cannot be sold back to the grid is $0.0748, resulting in 41.10% cheaper electricity per kWh. In the analysis regarding the resale of excess electricity produced in the designed hybrid energy system back to the grid, the unit price of electricity was calculated as $0.0387, providing electricity at 69.52% lower cost per kWh, along with 54.6% cleaner energy. Additionally, in the analyses conducted for similar public buildings in different geographic locations, regions that showed compatibility with the solar radiation values given in Turkey's Solar Energy Potential Atlas (SEPA) experienced a 50% reduction in unit energy prices. In the model that included electric vehicle charging stations as part of the hybrid energy system, the unit price of electricity was calculated as $0.0440, indicating a 65.35% reduction in the cost of electricity per kWh.