A whole Photovoltaic off grid system need five components asfollows:
Off -grid power generation system is made up of a number of individual solar modules usually of 12 volts with power outputs of between 50 and 300+ watts each. These PV panels are then combined into a single array to give the desired power output. Currently, the most cost-effective solar panels are those made up of 60, 72, 120 or 144 cells. These days, monocrystalline panels are the industry standard in most systems.
So why use monocrystalline instead of polycrystalline panels? It really comes down to availability and money. Most of the time monocrystalline panels are used in off-grid solar systems as the industry has shifted to manufacturing those types of panels instead of polycrystalline. In the early days, affordability gave the advantage to polycrystalline panels because they were cheaper to manufacture. Since that time, monocrystalline has become mainstream and affordable, so there isn’t a real advantage to using polycrystalline any longer.
In the solar power industry, there are two main battery chemistries – lead acid and lithium. The two main types of lead acid batteries used in solar are flooded lead acid batteries and sealed AGM batteries. Batteries are used to store the solar-produced electricity for nighttime or emergency use during the day. Depending upon the solar array configuration, battery banks can be of 12V, 24V or 48V and many hundreds of amperes in total.
The charge controller is the device that manages the flow of energy from the solar panels to the battery. Charge controllers make sure batteries are charged properly and are not overcharged which is important for the longevity of the battery bank. A charge controller regulates and controls the output from the solar array to prevent the batteries from being over charged (or over discharged) by dissipating the excess power into a load resistance. Charge controllers within a stand alone PV system are optional but it is a good idea to have one for safety reasons.
The inverter’s purpose is to take DC power that is stored in the battery bank and converting it to usable AC power and sending it to your loads so it can be used in the same manner as plugging into an AC outlet in a home. The inverter can be another optional unit in a stand alone system. Inverters are used to convert the 12V, 24V or 48 Volts direct current (DC) power from the solar array and batteries into an alternating current (AC) electricity and power of either 120 VAC or 240 VAC for use in the home to power AC mains appliances such as TV’s, washing machines, freezers, etc.
The final component required in and PV solar system is the electrical wiring. The cables need to be correctly rated for the voltage and power requirements.