Energy and environmental analysis of a hydrogen energy cogeneration system based on photovoltaic power generation for low-carbon building

The advancement and implementation of low-carbon buildings are crucial for global climate change mitigation and sustainable development. However, conventional single-energy systems often suffer from limited efficiency and high carbon emissions, highlighting the need for integrated and efficient multi-output energy solutions. This study proposes a novel cogeneration system for simultaneous electricity, hydrogen, and heat production based on photovoltaic power generation, with operational parameters for electrolysis and fuel processes determined through parametric analysis. Energy and environmental assessments were conducted to evaluate system performance. The results show that the system achieves a peak solar power output of 125.68 kW/h, an alkaline electrolysis hydrogen production rate of 708.9 mol/h, and a proton exchange membrane fuel cell power generation of 10.3 kW. The overall system efficiency reaches 0.90, representing improvements of 30.19% and 74.77% compared to standalone alkaline electrolysis and fuel cell systems, respectively. Additionally, the system can reduce CO₂ emissions by 352,451 kg annually, demonstrating significant potential for enhancing energy efficiency and supporting decarbonization in the building sector.