Design, Integration and Experimental Evaluation of a Hybrid Solar--Biogas Energy System with Regenerated Lithium-Ion Battery Storage

Dr Godwill Vegah Imbonzugah¹, Tamajon Fru Fofang3, Dr Li Yao4, , ¹ Adaptive E-Learn Systems (ADES) Ltd, Manchester, UK ² Manchester Metropolitan University, UK ³ College of Technology, UB-Cameroon 4Q-Energy, MSP, Manchester ABSTRACT This paper presents the design, integration, and experimental evaluation of a hybrid renewable energy system combining solar photovoltaic (PV) generation, anaerobic digestion-based biogas production, and energy storage using regenerated lithium-ion batteries derived from recycled battery materials. The proposed system integrates a 3–5 kWp PV array, a mesophilic anaerobic digester (1–2 m³), and a regenerated battery storage unit (5–10 kWh) through a hybrid inverter to enable coordinated energy management. Solar energy harvested during daylight hours is stored in regenerated batteries and utilised to maintain digester-operating temperature (~30 °C) and supply electrical loads during non-solar periods. Experimental testing demonstrates stable digester thermal regulation, continuous biogas production from cattle manure substrate, and effective battery charge–discharge performance. Preliminary analysis indicates measurable operational CO₂-equivalent emission reductions compared to fossil-fuel-based energy supply. The results confirm the technical and applcable integration of solar PV, biogas generation, and recycled battery storage within a single decentralised energy architecture, offering a scalable and sustainable solution for households, community centers, institutions as well as agriculture-sector green/sustainable energy applications. Keywords: Hybrid renewable energy systems; solar photovoltaic; biogas; anaerobic digestion; energy storage; lithium-ion battery recycling; decentralised energy.