One of the most efficient methods to utilize full-spectrum solar energy: A photovoltaic-thermoradiative coupled system

Highlights: • A concentrated solar spectrum photovoltaic-thermoradative coupled system is proposed. • Maximum efficiency and corresponding values of other parameters are calculated. • Optimum selection criteria of several main parameters are provided. • The proposed system can obtain a large efficiency under low solar concentration. • Optimal performances obtained here are superior to those of other related systems. Solar photovoltaic cells are widely used in many aspects, but a mass of solar energy cannot be utilized, resulting in much waste heat being dissipated into the environment, which limits the performance of photovoltaic cells. To improve the utilization of solar energy, a novel model of the concentrated solar spectrum photovoltaic-thermoradiative coupled system is established, where main irreversible losses in the system are considered. Expressions for the power outputs and efficiencies of two subsystems and coupled system are derived. The effects of the voltage outputs and bandgap energies of two cells, area ratios of different units, and the concentration factor on the performance of the coupled system are investigated in detail. The maximum efficiency and corresponding power output density of the coupled system are numerically calculated. The optimal selection criteria of the main parameters affecting the systemic performance are provided. Two subsystems are optimally matched. The performance characteristics of the coupled system are revealed. Compared with the photovoltaic cell and thermoradiative cell alone, the proposed system has a large efficiency enhancement. Compared with other photovoltaic-based coupled systems, the proposed system can be operated at low solar concentration and the maximum efficiency can attain 44.91%, which has a significant efficiency improvement.