Off-grid PV power generation system mainly by the PV modules, brackets, controllers, inverters, batteries and power distribution system components. System electrical design, the main consideration components, solar controller, solar inverter , battery selection and calculation. Before the design, the preparatory work need some time. You need to understand the user installation site of the climatic conditions, load type and power; day and night electricity consumption. Of course, need to know the user's budget and economic situation. In off grid PV power generation system, electricity is depend on weather. However,weather changed frequently.

After know the above situation, you can start to do the design.

Three principles of off - grid PV power generation system design

1.According to the user's load type and power to determine the power of off-grid inverter, home load is generally divided into inductive and resistive load, washing machine, air conditioning, refrigerator, water pump, range hood with motor load is emotional load , The motor starting power is 5-7 times the rated power, in the calculation of the inverter power, the load should take into account the starting power. The output power of the inverter is greater than the power of the load. For the monitoring station, communication stations and other demanding occasions, the output power is the sum of the load power. However, for the general poor households, taking into account all the load can not be opened at the same time, in order to save costs, you can multiply the sum of the load power of 0.7-0.9 coefficient.

2.According to the user's daily electricity consumption to confirm the component power. The design principle of the component is to meet the daily demand for daily electricity consumption under average weather conditions, that is to say, the annual electricity generation of solar modules should be equal to the annual electricity consumption of the load. Because the weather conditions are below and above the average, the solar cell components are designed to meet the needs of the worst season of light, that is, in the worst season, the battery can be basically filled with electricity every day. But in some areas, the worst season of the light is much lower than the annual average, if the worst case design of the solar cell module power, then the other time in the year when the power generation will be far more than the actual needs , Causing waste. At this time can only consider the appropriate increase in the design capacity of the battery to increase the energy storage, so that the battery is in a shallow discharge state, to make up for the light of the worst season power generation capacity of the damage caused by storage turbidity. The power generation capacity of the module can not be completely converted into electricity, but also consider the efficiency of the controller and the loss of the machine and the loss of the battery, the solar controller has two types of PWM and MPPT, PWM controller efficiency of about 85%, the input voltage range Relatively narrow, but the price is relatively low, MPPT controller efficiency of about 95%, the price is relatively high. Battery charge and discharge process, there will be 10-15% loss.

Off-grid system available power = total power of components * average number of solar power generation * controller efficiency * battery efficiency.

3.according to the user at night or expect standby time to determine the battery capacity. The task of the battery is to reduce the amount of solar radiation, the system to ensure the normal load of electricity. For important load, to be able to within a few days to ensure the normal work of the system, to consider the number of consecutive rainy days. For the general load such as solar lights can be based on experience or need to choose within 2 to 3 days. Important loads such as communication, navigation, hospital treatment, etc. in 3 to 7 days selected. Also consider the installation location of the photovoltaic power generation system, if in remote areas, the battery capacity to design a larger, because the maintenance staff to reach the scene will take a long time. In practice, some mobile communication base stations are very convenient because they are far away from the mountain. In addition to the configuration of the normal battery pack, a set of spare battery packs is provided. For the poor families, the main consideration is the price. Rainy days, the sun is good when used. When the sun is not good use, no sun is not used. Select the load, try to use energy-saving equipment, such as LED lights, inverter air conditioner. The design of the battery mainly includes the design of the battery capacity and the design of the combination of the battery string and parallel. In the photovoltaic power generation system, most of the use of lead-acid batteries, taking into account the battery life, generally take the depth of 0.5-0.7 between the discharge.

Battery design capacity = (load daily electricity consumption * continuous rain days) / battery discharge depth.

JNGE series of solar power generation system are sets of solar panel, battery, charge controller, inverter,and so on. We can provide you with off grid solar power system home, DC to AC pure sine wave inverter and low frequency pure sine wave inverter, etc.