Sustainable multigeneration via hybrid biomass-solar energy: Dynamic modeling, thermochemical storage, and green methane production

Abstract

This paper presents the conceptual design, dynamic modelling, and comprehensive performance analysis of a novel biomass-solar hybrid multigeneration system producing heating, electricity, and green methane. This system integrates advanced thermodynamic components, including a supercritical CO₂ cycle, the S-Graz power cycle, a heliostat field, and a thermochemical energy storage subsystem utilizing the reversible CaCO₃/CaO reaction. To enable continuous 24-h operation, the system is configured in two distinct modes: a solar-driven daytime mode and a nighttime mode powered by stored thermal energy. A PEM electrolyzer and a methanation reactor are incorporated to convert captured CO₂ and produced hydrogen into green methane, promoting carbon circularity. A thorough 4E (energy, exergy, economic, and environmental) analysis is conducted alongside a detailed parametric and dynamic investigation across seasonal and hourly variations. Two different scenarios regarding methane generation are also considered and compared. Economic analysis yields a net present value of $44.83 million, an internal rate of return of 20.53 %, and a levelized cost of electricity of 8.01 cents/kWh, with a simple payback period of 6.03 years. Sensitivity analyses reveal that solar irradiance, biomass feed rate, and thermochemical heat storage ratios significantly impact overall system performance. The proposed hybrid system demonstrates a viable pathway for low-emission, multi-output energy production by integrating renewable resources with innovative carbon reuse technologies.