Design and Performance Analysis of a Ground-Level Solar Thermal Accelerated Turbine (GSTAT) for Compact Power Generation

Abstract

This study analyzes the Ground-Level Solar Thermal Accelerated Turbine (GSTAT) system, a novel solar thermal technology that eliminates tall chimney structures while maintaining efficient energy conversion. The system features a 244 m diameter main collector, 117 m secondary collector, 10 m horizontal turbine, and 5 m crushed gravel thermal storage layer. Mathematical modeling employs Navier-Stokes equations, energy equations with Boussinesq approximation, and k-ε turbulence modeling. Under 1000 W/m² solar insolation, the system achieves 420 K ground surface temperature (112 K rise), accelerating airflow from 1 m/s inlet velocity to 14 m/s at the turbine. The crushed gravel storage layer provides 89.73% collector efficiency and enables extended operation beyond peak solar hours. CFD analysis confirms smooth velocity transitions and optimal thermal gradients throughout the system. Net electrical output reaches 163.35 kW, accounting for turbine efficiency (85%), generator efficiency (92%), and overall system losses (95% efficiency). Economic analysis yields an LCOE of $0.22-0.33/kWh, competitive with conventional solar chimney systems ($0.15-0.30/kWh) while offering reduced construction complexity and land use requirements. The GSTAT system shows particular promise for distributed power generation where tall structures are impractical, providing a scalable alternative to conventional solar updraft towers.