Combination of a light funnel concentrator with a deflector for orientated sunlight transmission

• A new type of the centralized solar energy collecting system has been developed.
• The system achieved 39% optical efficiency for half paraboloid deflector.
• The maximum energy density of the focal speckle reaches 2500 W/m2.

This study presents the design of a centralized solar collection system based on combination of a light funnel concentrator with a deflector. The combined light funnel/deflector unit can guide the concentrated light onto a centralized solar receiver, which could be considered as an alternative to solar towers, but could be conveniently installed on the ground. A number of light funnel/deflector units could form an array of solar concentrators. Each unit can convert the incident sunlight into a parallel light beam with high density and guide it onto the central receiver by a deflector, so an array of such units enable the central receiver to produce solar heat at high intensity and high temperature. A ray tracing simulation is used to demonstrate the feasibility of this new design of a centralized solar collection system and to determine the optical efficiency and light intensity distribution on the centralized receiver. The working principle of the system is also verified experimentally. The light intensity distribution on the receiver at different distances from the deflector outlet is presented. The results show that, for the receiver distance of 1.0 m, the optical efficiency of a light funnel/deflector unit can reach 37.5% and 35% for a whole and a half paraboloid deflector being used, respectively. The maximum energy density of the focal speckle on the receiver reaches 2500 W/m2.