How to Choose a Solar Panel

A solar cell is a device that directly converts light energy into electrical energy through the photoelectric effect or photochemical effect. Thin-film solar cells that work on the photoelectric effect are the mainstream, and how to choose and buy solar cells puzzles some people. Today, I will briefly introduce the knowledge about solar battery purchases. Hope it helps you.

Solar cells currently on the market are divided into amorphous silicon and crystalline silicon. Among them, crystalline silicon can be divided into polycrystalline silicon and single-crystal silicon. From the perspective of the photoelectric conversion efficiency of the three materials: monocrystalline silicon (up to 17%)>polycrystalline silicon (12-15%)>amorphous silicon (about 5%). However, crystalline silicon (monocrystalline silicon and polycrystalline silicon) basically does not generate current under weak light, and amorphous silicon has a good weak light type (the energy is inherently low under weak light). Therefore, on the whole, it is suitable to use monocrystalline silicon or polycrystalline silicon solar cell materials.

When we purchase solar cells, the focus of attention is the power of solar cells. Generally speaking, the power of solar panels is directly proportional to the area of solar chips. The area of the solar cell wafer is not exactly equal to the area of the solar package panel, because although some solar panels are large, the gaps arranged by single solar wafers are very wide, and the power of such solar panels is not necessarily high.

Generally speaking, the larger the power of the solar panel, the better, so that the current generated under the sun is large, and the built-in battery can be fully charged quickly. But in reality, it is necessary to find a balance between the power of solar panels and the portability of solar chargers. It is generally believed that the minimum power of the solar charger should not be lower than 0.75w, and the sub-power solar panel has a current of 140mA under standard strong light. The current generated under normal sunlight is about 100mA. If the charging current is too small under the sub-power, basically there will be no obvious effect.

With the widespread use of various solar products, solar cells are more and more widely used in our lives. But in the face of all kinds of solar cells on the market, how should we choose?

  1. Selection of solar cell battery capacity

Since the input energy of the solar photovoltaic power generation system is extremely unstable, it generally needs to be equipped with a battery system to work, and solar lamps are no exception, and must be equipped with a battery to work. Generally, there are lead-acid batteries, Ni-Cd batteries, and Ni-H batteries, and their capacity selection directly affects the reliability and price of the system. The selection of battery capacity generally follows the following principles: First, on the premise of meeting the night lighting, store the energy of the solar cell components during the day as much as possible, and at the same time, be able to store the electric energy that meets the night lighting needs of continuous rainy days. If the battery capacity is too small, it cannot meet the needs of night lighting. If the battery capacity is too large, on the one hand, the battery will always be in a state of power loss, which will affect the life of the battery and cause waste.

  1. Choice of solar cell packaging form

At present, there are two main packaging forms of solar cells, lamination and epoxy. The lamination process can guarantee the working life of solar cells for more than 25 years. Although the epoxy was beautiful at the time, the working life of solar cells is only 1 to 2 years. Therefore, low-power solar lawn lights below 1W can be packaged in the form of glue if there is no excessive life expectancy. For solar lights with a specified service life, it is recommended to use laminated packaging. In addition, there is a kind of silicone gel used for glue-encapsulating solar cells, and it is said that the working life can reach 10 years.

  1. Selection of solar battery power

The output power Wp of the solar cell we are talking about is the output power of the solar cell under the standard sunlight conditions, namely: the 101 standard defined by the European Commission, the radiation intensity is 1000W/m2, the air quality is AM1.5, and the battery temperature is 25°C. This condition is about the same as the sun light conditions around noon on a sunny day, (it can only approach this value in the lower reaches of the Yangtze River). It can also be used normally under the fluorescent lamp at night. That is to say, the output power of the solar cell is random. At different times and in different places, the output power of the same solar cell is different. Solar lamp materials, between the beauty and energy saving, most of them choose energy saving. The most ideal tilt angle for solar cells in the lower reaches of the Yangtze River is about 40 degrees, and the direction is due south.

Leave a Reply

Your email address will not be published. Required fields are marked *