Solar panels consist of solar cells connected in series and parallel. Commonly used cell specifications include 125 x 125 mm monocrystalline cells, with a power of approximately 2.5 to 2.8 W, and 156 x 156 polycrystalline cells, with a power of 3.3 to 4. 0 W. Crystal measures 156 x 156 mm, power is 4.0-4.5 watts; the voltage of each cell is about 0.5V. One square meter of battery panel uses different battery slices and has different combinations of series and parallel connections. Typically, panel voltages are 18V and 36V; They are used in 12V and 24V off-grid systems respectively.
1 square meter of crystalline silicon solar panel is approximately 120-140W., 6 times a day The sun at this time is 120*6=720WH. A 10 W lamp depends on the number of hours of use per day and the number of days of plconsecutive uies that it needs. If used 9 hours a day and 3 rainy days, the battery panel will be 30-50W.
The costs required according to regions, different installation difficulties, different roofs and the different installation methods are slightly different. The above calculations are for common installation methods.
Principle of energy production
The solar cell is a device that reacts to light and can convert light energy into electricity. There are many types of materials that can produce photovoltaic effects, such as: monocrystalline silicon, polycrystalline silicon, amorphous silicon, gallium arsenide, copper selenium indium, etc. Their principles of energy production are basically the same. Today, crystalline silicon is used as an example to describe the photovoltaic power production process. Crystalline siliconP-type n is doped with phosphorus to obtain N-type silicon, forming a P-N junction.
When light irradiates the surface of the solar cell, part of the photons are absorbed by the silicon material; the energy of the photons is transferred to the silicon atoms, causing the electrons to transition and become free electrons. accumulate on both sides of the P-N junction to form a potential difference, when the external circuit is connected, under the action of this voltage, a current will flow through the external circuit to produce a certain output power. The essence of this process is: the process of converting photon energy into electrical energy.