A typical solar system consists of solar modules, charge controller, battery bank (for DC loads) & with an inverter (for AC loads).
Solar Modules are made up of solar cells connected in series to produce the required voltage of the module. Modules are rated at 12V or 24V and can be connected in series to form 48V, 120V or higher voltage systems.
Power output is increased by connecting the solar modules in parallel. Modules can be rigid, flexible, framed or unframed. Types of modules include mono crystalline silicon, poly crystalline silicon, amorphous silicon, thin film, etc.
Charge Controller (for DC Bus)
This unit is the heart of the DC bus system. The solar modules, battery bank and loads are connected via the charge controller.
It functions include charging the battery via the solar modules, protecting the battery from overcharging and over discharging, controls the loads, indicates the SOC of battery bank and solar charging and prevents the battery from overcharging and over discharging.
Preferably deep discharge cyclic batteries whose capacity is taken at C100. Can be flooded or maintenance free. Types of batteries used include VRLA, GEL, NiCd and others.
Battery autonomy is generally set at >5 days Batteries are connected in series and parallel to match system voltage and capacity. Capacity & life cycles of batteries are affected by temperature and depth of discharge.
Generally, needs to be compensated for this loss by oversizing the batteries by a suitable factor. Battery storage allows operation at night and during bad weather
Inverter (for AC Loads)
Inverters convert the DC current produced from the solar modules to AC current. There are 2 types of inverters namely Grid tied inverters (AC bus) and Stand Alone Inverters (DC bus).
Rating of inverters are determined as close as possible to maximum AC load to optimize the inverter use. Inverters are connected directly to battery bank and not through the charge controller in the DC bus system.