The energy storage battery is indispensable in the off-grid system. The solar panel charges the energy storage battery through the controller, and the iron-lithium battery inverts the output for the user through the off-grid inverter. The energy storage battery is used in the photovoltaic off-grid system. The most commonly used are lithium iron phosphate batteries, lead-acid batteries, etc.
Photovoltaic modules, off-grid inverters (including photovoltaic chargers/inverters), energy storage batteries (lead-acid/colloid/lead-carbon/ternary lithium/lithium iron phosphate, etc.), photovoltaic brackets, cables, and accessories Electric boxes, etc. are all important components of photovoltaic off-grid systems. The biggest difference between photovoltaic off-grid systems and grid-connected systems is that grid-connected systems are based on investment income, while off-grid systems are based on just-needed power supply, so they will have different focus when selecting components.
In photovoltaic off-grid systems, energy storage lithium iron phosphate batteries account for a large proportion, and the cost is similar to that of solar modules, but the lifespan is much shorter than that of modules. The task of energy storage iron lithium batteries is to store energy and ensure stable system power. Guaranteed load power consumption in cloudy and rainy days.
1. The photovoltaic power generation time and the load power consumption time are not necessarily synchronized. In the photovoltaic off-grid system, the input is the component, which is used for power generation, and the output is connected to the load. 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. Many households use off-grid power stations to use electricity at night. What to do with the electricity generated during the day? First, the energy storage device is the energy storage lithium iron phosphate battery. Wait for the peak of electricity consumption, such as seven or eight o'clock in the evening, and then release the power.
2. Photovoltaic power generation and load power are not necessarily the same. Photovoltaic power generation is affected by radiation, which is not very stable, and the load is not stable, such as air conditioners and refrigerators. The load will cause the system to be unstable, and the voltage will fluctuate. The energy storage battery is a power balancing 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. .
Third, the cost of off-grid systems is high. The off-grid system consists of photovoltaic arrays, solar controllers, inverters, battery packs, loads, etc. Compared with the grid-connected system, there are more batteries, which occupy 30-40% of the cost of the power generation system, which is almost the same as the components. Moreover, the service life of the battery is not long. The lead-acid battery is generally 3-5 years, and the lithium battery is generally 8-10 years, and needs to be replaced after that.
The new energy storage lithium iron phosphate battery, as the energy storage device of the photovoltaic system, the energy storage efficiency can be increased to 95%, which can greatly reduce the cost of solar power generation. Lithium batteries have an energy efficiency of 95%, while the commonly used lead-acid batteries are only about 80%. Lithium-ion batteries are lighter in weight and have a longer lifespan than lead-acid batteries. Charge and discharge cycles can reach 1,600 cycles, which means they don't need to be replaced as often.
At present, more and more photovoltaic power generation and energy storage use lithium batteries with technological breakthroughs. The market share of ternary lithium/lithium iron phosphate batteries is gradually increasing in photovoltaic off-grid systems, which is a new application trend.
Summary: Lithium battery energy storage has gradually increased the proportion of newly installed capacity in various energy storage systems in recent years. According to the application status and battery characteristics of energy storage power stations at home and abroad, it is recommended that the battery selection of energy storage power stations is mainly lithium iron phosphate batteries.
