A note on solar panels
1, solar panels are the stronger the sun's light vertical irradiation intensity, the greater the output voltage, power and current.
2, the nominal rated power and current parameters are measured in the laboratory ideal light intensity conditions, the usual use is not reached, in
Under the hot sunlight at noon in summer, it can only be close to the rated power and rated current. The rated value is the value of the V.I.D. 3, no sunlight, cloudy light, indoor lighting and winter light is not strong and other environments, the solar panel output capacity is very weak.
The energy carried by these light is very small, even if it is brighter. The output voltage may also be higher under these lights, but it will be pulled down to about OV when connected to a load. And bright and can illuminate the object hot light, carrying the light energy is only high.
4, solar panel output voltage may be high when no-load, is normal, the output voltage does not have a voltage regulator, connected to the load voltage
Will be pulled down, the smaller the load impedance, the larger the current, the more the voltage is pulled down.
5, measurement of solar panel output current, you can use a multimeter tuned to DC current gear and a large number of range jack, the red pen connected to the positive terminal of the solar panel, the black pen connected to the negative terminal of the solar panel, to the direct sunlight for measurement.
6, it is recommended that the choice of solar panels, voltage parameters can match their desired voltage value or can be high, or choose a high voltage with buck module voltage regulation, power and current parameters try to use the required power and current value of about two times and more. 7, solar panels are not batteries, do not have a storage function, there is light on the output, there is no light on the output. Can be connected to a rectifier diode at the positive output to prevent the current backflow when the light intensity is insufficient.
 
Introduction to solar panels.
Solar cells, also known as "solar chips" or "photovoltaic cells", are thin photovoltaic semiconductors that use sunlight to generate electricity directly. The direct conversion of light - electricity is the use of photoelectric effect, the direct conversion of solar radiation energy into electricity, light - electricity conversion of the basic device is the solar cell. Solar cell is a kind of device that converts sunlight into electricity directly due to photovoltaic effect, it is a semiconductor photodiode, when the sunlight shines on the photodiode, the photodiode will turn the sun's light energy into electricity, producing current. When many cells are connected in series or in parallel, it can become a solar cell array with a relatively large output power.
 
What is a solar drip panel.
A solar drip panel is a type of solar panel, but the packaging method is different. By laser cutting the solar cell into small pieces, making the required voltage and current, and then encapsulating. Because of the small size, it is generally not encapsulated in a way similar to solar photovoltaic modules, but covered with epoxy resin for solar cells and bonded with PCB circuit boards, which has the characteristics of fast production speed, pressure and corrosion resistance, beautiful crystal appearance and low cost. 

Description of nominal parameters
1、Since the output power of solar panel depends on solar irradiance and solar
Panel temperature and other factors, so the solar panels are measured under standard conditions, the standard conditions are defined as:atmospheric mass AM1.5, light intensity 1000W/m2, temperature 25℃.
2, in this condition, the solar panel output curtain high power is called peak power
Rate (rated power), in many cases, the peak power of the module is usually measured with a solar simulator, the actual use of the sun's light intensity does not reach the strength of the test conditions, so the peak power is generally not reached. 
3. The nominal voltage and rated current are tested under the connected load.
Light intensity and temperature can reach the peak voltage and current, the actual use even in the summer noon hot sunlight, but also can not reach the test conditions, so there is the following relationship.
Open-circuit voltage (not connected to the load) > rated voltage > actual working voltage 
Short-circuit current (output short circuit) > rated current > actual working current 
The main factors affecting the output performance of solar panels are as follows. 
(1) Load impedance
(2) Sunlight intensity 
(3) Temperature
(4) Light angle and light area 

Cautions
1. Solar energy cannot store electricity, so it must be directly exposed to the sun to have electricity. 
2. Solar panels can not be used in cloudy and rainy days.
3. Solar energy can not be used in indoor lighting. 
4. Solar energy shining through the window can not be used.