Feasibility study of a flexible hybrid energy model with power-hydrogen production in wastewater treatment plant

Abstract

Renewable energy systems have garnered increasing attention as a viable solution to global warming and climate change. A key challenge in advancing renewable energies lies in ensuring energy stability, a concern effectively addressed through hybridization. Wastewater treatment plants, with their high energy consumption and potential for renewable energy integration, offer an opportune platform for implementing these systems. This paper introduces a flexible model for a hybrid energy system encompassing solar, wind, and biogas energy, seamlessly connected to the grid. The system is designed with three primary objectives: meeting the energy demand of the treatment plant, supporting the grid by selling excess energy during power outages, and generating green hydrogen. The treatment plant's average daily consumption is 10.28 MWh. Optimization using HOMER Pro resulted in the selection of System A as the most efficient configuration, comprising 1924 kW solar panels, two 1.5 MW wind turbines, a 500 kW biogas generator, a 578 kW converter, and a 1270 kW electrolyzer, with an initial cost of USD 2.41 million. The Net Present Cost (NPC) and Cost of Energy (COE), without factoring in hydrogen sales revenue, were determined to be USD 4.88 million and USD 0.057 per kWh, respectively. During the power blackout periods in July, August, and September, which are the main outage months, the system significantly improved grid stability by selling a total of 1515 MWh of energy, thereby providing crucial support to the grid. On average, the system produces 82.45 tons/year of green hydrogen, with hydrogen sales reducing the NPC to USD 657,000.The carbon reduction achieved by this system amounts to 1792 tons/year. In conclusion, the proposed hybrid energy system demonstrates the potential of multi-task energy models, shaping a future where diverse facilities meet their energy needs, enhancing sustainability in both individual systems and the broader grid. This study offers valuable insights for policymakers, researchers, and activists striving to advance global clean energy and sustainable development goals.