1. Solar cell array
The smallest unit used for photoelectric conversion is the solar cell. Its size ranges from 4 to 100 cm², its operating voltage is 0.45 to 0.50 V, and its operating current is 20 to 25 mA/cm², therefore it cannot be used as a standalone power source. In a photovoltaic power generation system, solar cells need to be connected in series and parallel and encapsulated to form solar cell modules. Their power output can range from a few watts to hundreds of watts, and they can be used as standalone power sources. A solar cell array, on the other hand, consists of solar cell modules connected in series and parallel and mounted on a support structure. It can output hundreds of watts, kilowatts, or even greater power, serving as the power generator of a photovoltaic power generation system.
2. Solar storage battery
Independent photovoltaic (PV) power generation systems rely on batteries to store excess electrical energy, thus batteries play a crucial role in these systems. Currently, many types of batteries are commonly used in PV systems, with the most widely applied being ordinary lead-acid batteries, alkaline nickel-cadmium batteries, and maintenance-free lead-acid batteries.
As the price of solar cell modules decreases, the proportion of battery costs in the total system investment will gradually increase. Therefore, selecting the appropriate battery type and capacity, accurately implementing installation and operation, and carefully maintaining the system are crucial for the normal operation of a stand-alone solar photovoltaic power generation system.
3. Power electronic converter (inverter)
Solar cell arrays generate direct current (DC) under sunlight, but most common household loads require alternating current (AC), such as fluorescent lights, televisions, refrigerators, electric fans, and air conditioners, as well as the vast majority of power machinery. Therefore, a device is needed to convert DC to AC; this is the inverter.
An inverter in a photovoltaic (PV) power generation system is a converter circuit that transforms the direct current (DC) generated by the solar cell array into alternating current (AC) with varying frequencies and voltages. Therefore, except for special users, inverters are required in almost all PV power generation systems. Furthermore, inverters have automatic or manual voltage regulation functions, which can improve the power quality of the PV power generation system. Clearly, inverters are an indispensable and crucial component of PV power generation systems.
