Thin Film Solar Charge Controller: A Research Paper for Commercialization of Thin Film Solar Cell

Abstract

Solar Home System comprise with Solar PV, battery, and solar charge controller. Solar panels convert sunlight energy into electric energy by an electro-chemical process called photovoltaic process. Battery store electrical energy throws chemical reaction between acid and electrode. During discharge, stored chemical energy convert into electrical energy is then use for illumination lamp and running others electrical appliances. Most of cases solar energy consumer use solar energy at evening hours, but it is available in day time. So, it is required to store solar energy into battery. Each battery has certain limit of capacity. Battery lifetime reduces due to overcharging and deep discharging. As battery is very expensive component of solar home system. So, it is essential to protect from over charging and deep discharging. In this case charge controller plays a vital role to protect this battery. A solar charge controller, or charge regulator is similar to the voltage regulator. It regulates the voltage and current coming from the solar panels and going to the battery. Most of batteries are fully charged at 14 to 14.5 volts. On the other hand batteries life time drastically reduces due to discharge over the level of 70 – 80% DOD; at this discharge level the battery voltage normally goes down to 11.5±0.2 volts. The aim of this work is to study design and implementation a thin film solar charge controller for commercialization the thin film solar system. In Bangladesh, all supplier has involved with mono-crystalline solar and poly-crystalline solar, but no one deal with thin film solar system; due to lack of appropriate solar charge controller for solar home system (SHS). Thin film solar system is cheapest than other solar system and its installation accessories are obtainable in the local market to purchase in easy approach.