Direct Solar PV-LED Lighting System

With the increasing impact of climate change seen in present decades, an efficient, low cost, low carbon foot print, low embedded energy, and very robust energy systems are required. Many organizations for example the schools, government offices, and industries run in the daytime having lighting, cooling and heating requirements. For many applications, the operations of these devices are non-critical and need not to run precisely at constant luminescence (in lights) or at constant speed. The day time energy production by Solar PV is in line with daytime loads. This paper presents simple, robust and cost-effective ways to meet daytime lighting load for noncritical operations without energy storage or power condition. We call this as Direct Solar (DS) PV-LED lighting systems. For the design of DS PV lighting systems for a given LED pack we have identified the method to identify the optimum solar PV module parameters like the number of cells in series, size of solar cells to be able to operate the under all possible operating conditions (such as low light conditions and high temperature conditions). Different operating regions for LED are compared with design of different solar PV modules obtained by varying number of solar cells. Configuration with LED operating closer to the short circuit current (by increasing the number of cell in series) of the module is found to be more suitable than when LED operating at maximum power point of the module. This increases the luminescence of LED by increasing the current, and the robustness of the system design