From the current point of view, there are two typical applications of photovoltaics, grid-connected systems and off-grid systems. The grid-connected system depends on the power grid, and adopts the working mode of "self-generated and self-consumption, surplus power on-grid" or "full on-grid". The off-grid system does not depend on the power grid, and adopts the working mode of "storage and use" or "first storage and then use". For households in areas without grid or frequent power outages, off-grid systems have strong practicality. At present, more and more individual users have purchased Improve lifepo4 batteries for off-grid systems.
In photovoltaic off-grid systems, energy storage batteries account for a large proportion, and the cost is similar to that of solar modules, but the lifespan is shorter than that of modules. The task of the energy storage battery is to store energy, ensure the stability of the system power, and ensure the load power consumption at night or in cloudy and rainy days. Off-grid systems must be equipped with energy storage batteries, why?
First, the photovoltaic power generation time and the load power consumption time are not necessarily synchronized. Photovoltaic generates electricity during the day, and only generates electricity when there is sunlight. Usually, the power generation is the highest at noon. However, at noon, the demand for electricity is not high, and many loads only use electricity at night. What about the electricity generated during the day? To store energy first, this energy storage device is an energy storage battery. Wait for the peak of electricity consumption, such as seven or eight o'clock in the evening, and then release the power.
Second, photovoltaic power and load power are not necessarily the same. Photovoltaic power generation is affected by radiation and is not very stable, and the load is also unstable. Like air conditioners and refrigerators, the starting power is very large, and the operating power is usually less. The load will cause the system to be unstable, and the voltage will fluctuate. Improve lifepo4 batteries are equivalent to a power balance device. When the photovoltaic power is greater than the load power, the controller sends the excess energy to the battery pack for storage. When the photovoltaic power cannot meet the load needs, the controller sends the battery power to the load.