Ewod-controlled dual liquid prism for adaptive beam steering

Abstract

Solar energy accounts for the greatest source of renewable energy on the earth. The use of photovoltaic (PV) and concentrating photovoltaic (CPV) technology has been the most promising method of harvesting solar energy. These CPV systems often require bulky motor-driven tracking devicesto steer the sun's beams onto solar cells. The cost of providing and maintaining these tracking systems is the primary inhibitor for widespread application. The purpose of this work is to overcome the need for mechanical solar trackers through the use of an electrowetting-driven solar tracking (EWST) system. The electrowetting-driven solar tracking system consists of an array of novel electrowetting-assisted dual liquid prisms, which are filled with immiscible fluids that have large differences in refractive indices. The naturally formed meniscus between the fluids can function as a dynamic optical prism. Via the full range modulation of the liquid prisms, incident sunlight can be adaptively tracked, steered and focused onto concentrated photovoltaic cells through a fixed optical condenser (Fresnel lens). Furthermore, unlike the conventional, cumbersome motor-driven tracking systems used today, the liquid prism system introduced in this work would be suitable for rooftop application. The results of this work reveal that the EWST system has the potential to generate 70% more green energy at 50% of the vonventional PV capital cost.