Lithium Battery for PV Systems--IMPROVE BATTERY
September 07, 2022

Lithium Battery for PV Systems

Lithium iron phosphate batteries can be used for photovoltaic energy storage and power generation. The solar power generation system has high cost, low conversion efficiency, and strong variability with the environment, so the requirements for energy storage are relatively high. The service life of the solar photovoltaic power generation system is generally 20 years, and the supporting energy storage battery is required to have the characteristics of long service life, stable performance, high energy efficiency, and strong adaptability to the environment.

Compared with lead-acid batteries, lithium iron phosphate batteries have the advantages of high specific energy, high energy storage efficiency, long cycle life, and low cost of use. Lithium iron phosphate battery is a new type of secondary power source developed in recent years. It has the characteristics of large input and output power, wide operating temperature range, no memory effect, maintenance-free, 2000 times of charge and discharge life, safety and environmental protection. Is becoming the protagonist of chemical batteries.

The voltage platform of the lithium iron phosphate battery is 3.2V, the specific energy is more than twice that of the lead-acid battery, and the volume specific energy is 4 to 5 times that of the lead-acid battery. If the lithium iron phosphate battery is used instead of the lead-acid battery for photovoltaic power generation The system can greatly reduce the space occupied by the battery and reduce the maintenance workload.

Lithium iron phosphate battery can choose power type or energy type, has a wide range of applications, and its safety has been greatly improved compared with lead-acid batteries. At the same time, the rate characteristics of lithium iron phosphate batteries are 5C to 15C, and the conversion efficiency is greater than 95%, while the rate characteristics of lead-acid batteries are 0.1C to 1C, and the conversion efficiency is greater than 80%. Therefore, in terms of energy storage efficiency, lithium iron phosphate batteries have obvious advantages.

What are the requirements for the selection of photovoltaic energy storage lithium batteries?

As an energy storage power station that cooperates with photovoltaic power generation to realize peak shaving and valley filling, load compensation, and improve power quality application, energy storage lithium battery is a very important component, and must meet the following requirements:

①It is easy to realize multi-mode combination to meet higher working voltage and larger working current;

②The capacity and performance of lithium iron phosphate battery can be detected and diagnosed, so that the control system can realize the dispatching control of the power station load under the condition of predicting the battery capacity and performance;

③High safety and reliability: Under normal use conditions, the normal service life of the battery is not less than 15 years; in extreme cases, even if a failure occurs, it is still in the controlled range, and there should be no explosion, combustion, etc. that endanger the safe operation of the power station. Fault;

④ It has good fast response and high rate charge and discharge capacity, generally requiring 5–10 times the charge and discharge capacity;

⑤High charge-discharge conversion efficiency, easy installation and maintenance, good environmental adaptability, and wide operating temperature range