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Photovoltaic off-grid power generation system efficiently utilizes green and renewable solar energy resources, and is the best solution to meet the electricity demand in areas without power supply, power shortage and power instability.

1. Advantages:
(1) Simple structure, safe and reliable, stable quality, easy to use, especially suitable for unattended use;
(2) Nearby power supply, no need for long-distance transmission, to avoid the loss of transmission lines, the system is easy to install, easy to transport, the construction period is short, one-time investment, long-term benefits;
(3) Photovoltaic power generation does not produce any waste, no radiation, no pollution, energy saving and environmental protection, safe operation, no noise, zero emission, low carbon fashion, no adverse impact on the environment, and is an ideal clean energy;
(4) The product has a long service life, and the service life of the solar panel is more than 25 years;
(5) It has a wide range of applications, does not require fuel, has low operating costs, and is not affected by energy crisis or fuel market instability. It is a reliable, clean and low-cost effective solution to replace diesel generators;
(6) High photoelectric conversion efficiency and large power generation per unit area.

2. System Highlights:
(1) The solar module adopts a large-size, multi-grid, high-efficiency, monocrystalline cell and half-cell production process, which reduces the operating temperature of the module, the probability of hot spots and the overall cost of the system, reduces the power generation loss caused by shading, and improves. Output power and reliability and safety of components;
(2) The control and inverter integrated machine is easy to install, easy to use, and simple to maintain. It adopts component multi-port input, which reduces the use of combiner boxes, reduces system costs, and improves system stability.

1. Composition
Off-grid photovoltaic systems are generally composed of photovoltaic arrays composed of solar cell components, solar charge and discharge controllers, off-grid inverters (or control inverter integrated machines), battery packs, DC loads and AC loads.

(1) Solar cell module
The solar cell module is the main part of the solar power supply system, and its function is to convert the radiant energy of the sun into direct current electricity;

(2) Solar charge and discharge controller
Also known as "photovoltaic controller", its function is to regulate and control the electric energy generated by the solar cell module, to charge the battery to the maximum extent, and to protect the battery from overcharge and overdischarge. It also has functions such as light control, time control, and temperature compensation.

(3) Battery pack
The main task of the battery pack is to store energy to ensure that the load uses electricity at night or in cloudy and rainy days, and also plays a role in stabilizing the power output.

(4) Off-grid inverter
The off-grid inverter is the core component of the off-grid power generation system, which converts DC power into AC power for use by AC loads.

2. Application Areas
Off-grid photovoltaic power generation systems are widely used in remote areas, no-power areas, power-deficient areas, areas with unstable power quality, islands, communication base stations and other application places.

Three principles of photovoltaic off-grid system design

1. Confirm the power of the off-grid inverter according to the user's load type and power:

Household loads are generally divided into inductive loads and resistive loads. Loads with motors such as washing machines, air conditioners, refrigerators, water pumps, and range hoods are inductive loads. The starting power of the motor is 5-7 times the rated power. The starting power of these loads should be taken into account when the power is used. The output power of the inverter is greater than the power of the load. Considering that all loads cannot be turned on at the same time, in order to save costs, the sum of the load power can be multiplied by a factor of 0.7-0.9.

2. Confirm the component power according to the user's daily electricity consumption:

The design principle of the module is to meet the daily power consumption demand of the load under average weather conditions. For the stability of the system, the following factors need to be considered

(1) The weather conditions are lower and higher than the average. In some areas, the illuminance in the worst season is far lower than the annual average;

(2) The total power generation efficiency of the photovoltaic off-grid power generation system, including the efficiency of solar panels, controllers, inverters and batteries, so the power generation of solar panels cannot be completely converted into electricity, and the available electricity of the off-grid system = components Total power * average peak hours of solar power generation * solar panel charging efficiency * controller efficiency * inverter efficiency * battery efficiency;

(3) The capacity design of solar cell modules should fully consider the actual working conditions of the load (balanced load, seasonal load and intermittent load) and the special needs of customers;

(4) It is also necessary to consider the recovery of the capacity of the battery under continuous rainy days or over-discharge, so as to avoid affecting the service life of the battery.

3. Determine the battery capacity according to the user's power consumption at night or the expected standby time:

The battery is used to ensure the normal power consumption of the system load when the amount of solar radiation is insufficient, at night or in continuous rainy days. For the necessary living load, the normal operation of the system can be guaranteed within a few days. Compared with ordinary users, it is necessary to consider a cost-effective system solution.

(1) Try to choose energy-saving load equipment, such as LED lights, inverter air conditioners;

(2) It can be used more when the light is good. It should be used sparingly when the light is not good;

(3) In the photovoltaic power generation system, most of the gel batteries are used. Considering the life of the battery, the depth of discharge is generally between 0.5-0.7.

Design capacity of battery = (average daily power consumption of load * number of consecutive cloudy and rainy days) / depth of battery discharge.

1. The climatic conditions and average peak sunshine hours data of the area of use;

2. The name, power, quantity, working hours, working hours and average daily electricity consumption of the electrical appliances used;

3. Under the condition of full capacity of the battery, the power supply demand for consecutive cloudy and rainy days;

4. Other needs of customers.

The solar cell components are installed on the bracket through a series-parallel combination to form a solar cell array. When the solar cell module is working, the installation direction should ensure maximum sunlight exposure.

Azimuth refers to the angle between the normal to the vertical surface of the component and the south, which is generally zero. Modules should be installed at an inclination towards the equator. That is, modules in the northern hemisphere should face south, and modules in the southern hemisphere should face north.

The inclination angle refers to the angle between the front surface of the module and the horizontal plane, and the size of the angle should be determined according to the local latitude.

The self-cleaning ability of the solar panel should be considered during the actual installation (generally, the inclination angle is greater than 25°).

Efficiency of solar cells at different installation angles:  

Precautions:

1. Correctly select the installation position and installation angle of the solar cell module;

2. In the process of transportation, storage and installation, solar modules should be handled with care, and should not be placed under heavy pressure and collision;

3. The solar cell module should be as close as possible to the control inverter and battery, shorten the line distance as much as possible, and reduce the line loss;

4. During installation, pay attention to the positive and negative output terminals of the component, and do not short-circuit, otherwise it may cause risks;

5. When installing solar modules in the sun, cover the modules with opaque materials such as black plastic film and wrapping paper, so as to avoid the danger of high output voltage affecting the connection operation or causing electric shock to the staff;

6. Make sure that the system wiring and installation steps are correct.

Note: The actual power of the equipment shall prevail.