Evaluation of the influence of soil thermal inertia on the performance of a solar chimney power plant

Solar chimney power plants are a technology capable to generate electric energy through a wind turbine using the solar radiation as energy source; nevertheless, one of the objectives pursued since its invention is to achieve energy generation during day and night. Soil under the power plant plays an important role on the energy balance and heat transfer, due to its natural behavior as a heat storage system. The characteristics of the soil influence the ability of the solar chimney power plant to generate power continuously. Present work analyzes the thermodynamic behavior and the power output of a solar chimney power plant over a daily operation cycle taking into account the soil as a heat storage system, through a numerical modeling under non-steady conditions. The influence of the soil thermal inertia and the effects of soil compaction degree on the output power generation are studied. A sizeable increase of 10% in the output power is obtained when the soil compaction increases. ▸ Solar chimney power plants are a technology capable to generate renewable energy from solar radiation. ▸ The ground under the solar chimney can act as a heat storage system. ▸ The soil thermal inertia plays a relevant role in a scenario where the plant operates continuously. ▸ A higher compaction of soil causes a relevant increase on total energy generation.