Low-temperature geothermal resources remain underutilized due to poor thermal-to-work conversion efficiency. Cascaded multigeneration systems offer a solution by recovering waste heat through sequential cycles. However, no systematic comparison exists among different cascade topologies specifically, adding a regenerative ORC, a simple ORC, or a Kalina cycle as the final stage. This study fills that gap by proposing and comparing four geothermal-based multigeneration configurations (G-LiBr-PEM, G-LiBr-PEM-RORC, G-LiBr-PEM-RORC–ORC, and G-LiBr-PEM-RORC-KC) under identical source conditions. A comprehensive exergoeconomic analysis and multi-objective genetic algorithm optimization is performed. Key findings show that the Kalina-based system maximizes net power output (170.2 kW, 295 kW after optimization), while the ORC-based system achieves the highest exergy efficiency (58.18%) and sustainability index (1.55 after optimization). The baseline system delivers the highest heating capacity (998 kW) at the lowest cost. The main contribution is a quantitative decision framework: the Kalina configuration is recommended for power-priority applications, the ORC configuration for sustainability-priority applications, and the baseline for heat-dominated or budget-constrained projects. These results provide engineers with a clear, evidence-based selection guide for cascaded geothermal multigeneration systems.
