Mathematical Modeling of Roof Solar Chimney for Small Scale Power Generation

The OnRoof Solar Chimney is a simple technique for smallscale utilization of solar energy. In this paper, a
mathematical model is developed to describe the thermofluid behavior of the air in the chimney. A smallscale experimental model
with adjustable roof angle was built and was used to perform measurements to study the effects of roof angle and also daylong
performance of the model. The experimental study showed an adequate temperature rise in the system and validated the potential
to generate enough air flow to operate a Savonius wind rotor to produce electricity. The highest measured temperature for the
collector surface and the chimney exit were 97°C and 57.4°C, respectively. Computations were performed based on mixed
convection heat transfer mode inside the collector. The calculated power that could be produced for a building of 10m x 20m at
base roof area was1.36 kW, which demonstrated the feasibility of using OnRoof Solar Chimney to generate power for medium
sized buildings such as dormitories, schools, and public halls

Keywords: OnRoof Solar Chimney, Solar energy, Solar chimney