Solar panels are the most important solar panels of photovoltaic power system, accounting for nearly half of the system cost. Its technical characteristics are related to the detailed design of PV systems, so it is of great significance to read the technical parameters of Solar panel

Here we introduce detailedly Soliswatt Mono 300W Solar Panel mechanical parameters, electrical parameters, temperature rating parameters, limit parameters, quality assurance parameters, and related certifications. Through the detailed parameters introduction,  you can gain an in-depth understanding of the superior quality of Soliswatt solar panel.

Solar panel electrical performance parameters

Taking the 300W Soliswatt mono solar panel as an example, the electrical performance parameters are selected as follows:

The above tests are in accordance with STC "Standard Test Conditions", with an irradiance of 1000 W/m2, a solar panel temperature of 25 °C, and an air quality of AM 1.5.

The maximum power Pm

Pm=Im*Vm, corresponding to the vertices of the power parabola below.

The parabola is the power curve and the other is the UI curve.

[Interpretation: PV modular nominal parameter, generally based on "standard test conditions STC". As environmental conditions such as temperature and irradiance change, the corresponding parameters of the solar panel will change. In addition, the power characteristic curve of the solar panel like a parabolic, which has a highest point and is also the working point that the inverter MPPT "maximum power point tracking" needs to find. 】

Power tolerance

“0~+3%” stands for positive tolerance. For solar panel such as 300W, the power range is between 300W and 309W.

[Interpretation: The current first-line brand solar panels are positive tolerances]

The maximum power point operating voltage Vm

Corresponding to the abscissa corresponding to the power parabola vertex of the above figure, representing the working voltage of the solar panel at the maximum power.

The maximum power point operating current Im

The ordinate of the power parabola vertex of the above figure represents the operating current at the maximum power of the solar panel.

Open circuit voltage Voc

The open circuit voltage is the terminal voltage when the solar panel is not connected to the load. The intersection of the UI curve and the abscissa in the above figure, the value multiplied by the number of input solar panels of the inverter should be less than the maximum DC voltage of the inverter Vdcmax.

Short circuit current Isc

The short-circuit current is the output current when the solar panel is short-circuited, and the focus of the UI curve and the ordinate is shown above.

[Interpretation: The current is constant when solar panel connected in series, and the Isc and Im values ​​are key parameters to measure whether the maximum input current of the inverter meets the system design.

Solar panel efficiency

In theory, the solar panels of the same size and maximum power are definitely the same. When the irradiance is 1000 W/m2, the power received on the 1.635 m2 module is 1635 W, and when the output is 300 W, the efficiency is 18.44%, and at 310 W, it is 18.96%.

[Interpretation: Under the same environment, the larger the output power per unit volume, the higher the efficiency of the solar panels of this technology]

Solar panel mechanical parameters

Taking Soliswatt monocystal solar module as an example, the mechanical parameters are selected as follows:

Solar cell

Crystalline silicon solar panels: metallurgical silicon is made of high-purity quartz sand, and metallurgical silicon is crystallized by chlorine precipitation. Generally, the efficiency of single crystal modules is about 18%-19%.

[Interpretation: The solar cell is the smallest unit of photoelectric conversion, and the commonly used size is generally 156mm*156mm. The operating voltage of the solar cell is about 0.5V, and generally cannot be used alone. After the solar cells are packaged in series, they become photovoltaic solar panels.

Number of solar cells

A photovoltaic module typically consists of 60 (6 x 10) or 72 (6 x 12) cells.

Solar panel size

The common size is 1.635 m2 (0.992 m × 1.640 m) and 1.938 m2 (0.991 m × 1.956 m), and the size of the solar panels is an important factor in installation considerations.

Solar panel weight

The Soliswatt 300W solar panel (60 pieces), which is currently on the market, weighs about 18.8kg.

Backboard

Performance requirements for crystalline silicon cell solar panel backboard typically include:

·Good weather resistance

· No change in lamination temperature

· Strongly combined with EVA or POE

· Must have very low thermal resistance and can prevent water or water vapor from entering

[Interpretation: Do you know why the backboard is usually white? White helps the light in the gap between the cells to be reflected to the front surface, and some of the light will be reflected back to the solar cell, increasing the use of solar energy by the solar cell. Conducive to the improvement of photoelectric conversion efficiency]

Solar panel framework

The flat panel assembly must have a frame to protect the solar panels and facilitate the connection and fixing of the solar panels. The main materials of the frame are stainless steel, aluminum alloy, rubber and reinforced plastic.

[Interpretation: Conventional photovoltaic frames are generally made of aluminum. The frame structure should be free of protrusions to avoid the accumulation of water, dust or other objects. The thickness of the surface oxide layer is more than 10μm, which can ensure that it is not corroded in the outdoor environment for more than 30 years]

Junction box

The positive and negative terminals of the solar panel are connected to the designed cable in the junction box and connected to the external line.

·The shell has strong anti-aging and UV resistance

· Meet the requirements of outdoor harsh environment

·Excellent heat dissipation mode, effectively reducing internal temperature and meeting electrical requirements

·Good waterproof and dustproof

IP is the international code used to identify the level of protection. The IP (Ingress Protection) level consists of two numbers. The first number indicates dust protection. The second number indicates waterproof. The higher the number, the better the protection level.

[Interpretation: IP67 has a very high degree of protection, which can completely prevent dust from entering and can be immersed in water for a short time.]

Temperature rating parameters

This set of parameters mainly reflects the effect of temperature on some parameters of the solar panel:

Rated solar panel temperature

The rated solar panel temperature is the temperature reached when the solar module or solar panel is in an open state and is representative of the following.

Solar panel surface light intensity: 800 W / m2

Ambient temperature: 20 ° C

Wind speed: 1 m / s

Electric load: no (open circuit)

Inclination: 45° to the horizontal

Bracket structure: no building on the back (natural ventilation)

[Interpretation: This value is generally 45±2°C (solar panel operating temperature). Since the power temperature coefficient of the PV module is negative, the lower the rated solar panel temperature value, the better]

Power temperature coefficient

Power variation with temperature, in %/K, is negative

Voltage temperature coefficient

Voltage change with temperature, in %/K, is negative

Current temperature coefficient

Current varies with temperature in %/K, which is positive

[Interpretation: When the ambient temperature of the solar panel is lowered, the output current of the cell will decrease, and the voltage will increase accordingly. Therefore, designing the PV system string to match the inverter needs to consider the local extreme low temperature to prevent the string voltage from exceeding the inverse.

Limitation parameters

The following parameters reflect the extreme conditions under which the solar panel works:

Working temperature

The operating temperature of a solar panel is usually the range of external ambient temperatures at which the solar panel can operate.

[Interpretation: The operating temperature of general PV modules can meet the ambient temperature. But one day your needs will become a power station in the Antarctic, Arctic or even outer space, so please don't forget this parameter.

Maximum system voltage

The solar system voltage refers to a number of solar panels forming a solar power system, the maximum DC voltage of this power generation system; the maximum can be 1000V.

(Assume that the voltage temperature coefficient of the open circuit voltage Voc of the photovoltaic module is -0.32%, Voc=44.7V under the STC, and Voc=44.7*(1+0.32%*(25+40)) under the extreme operating low temperature -40 °C= 54V, generally requires the number of series solar panels in each string to be ≤1000/54=18). The standard system voltages for popular solar panels are 600V (US standard) and 1000V (European standard).

Maximum fuse rated current

This value will be greater than the maximum operating point operating current to protect solar panels and cables.

Taking a typical centralized power station as an example, in the current centralized power station, the number of strings connected in parallel is up to 100 strings. When there is a series of short-circuit faults, the currents of all the strings will reverse the fault group, and the reverse current may be reversed. More than 800A, far beyond the safety requirements of cables and solar panels, is prone to fire accidents, so fuses must be used to cut off fault currents and protect cables and solar panels.

Warrenty

Warranty is very important to customers, and it is usually desirable to have a longer warranty. However, even the best products will have a service life. The general PV module warranty is divided into product warranty and power generation warranty.

Certification

TUV/VDE,CQC