How to make your own solar power system

How to make your own solar power system

How to make your own solar power system

People have long discovered that solar energy is an inexhaustible energy source. Now with the increase in electricity prices, people are getting closer and closer to the direction of thinking about free solar power generation. Today I will introduce the method of making a homemade solar power generation system and personal technical insights.

The solar power generation system consists of solar cells, solar charge and discharge controllers, lead-acid maintenance-free batteries, inverters and lighting fixtures.

What is the principle of solar cells?

Sunlight shines on the p-n junction of the semiconductor, forming new hole-electron pairs. Under the action of the electric field of the p-n junction, holes flow from the n region to the p region, and electrons flow from the p region to the n region. After the circuit is turned on, a current is formed. This is how photovoltaic effect solar cells work. Solar power generation methods There are two ways of solar power generation, one is the light-heat-electricity conversion method, and the other is the light-electricity direct conversion method.

(1) The light-heat-electricity conversion method generates electricity by utilizing the thermal energy generated by solar radiation. Generally, a solar collector converts the absorbed thermal energy into steam as a working fluid, and then drives a steam turbine to generate electricity. The former process is a light-heat conversion process; the latter process is a heat-electricity conversion process, which is the same as ordinary thermal power generation. The disadvantages of solar thermal power generation are low efficiency and high cost. It is estimated that its investment is at least 5 to 10 times more expensive than ordinary thermal power plants. A 1000MW solar thermal power station requires an investment of 2.0 to 2.5 billion US dollars, and the average investment for 1kW is 2000 to 2500 US dollars. Therefore, it can only be used on a small scale in special occasions, and large-scale utilization is economically uneconomical and cannot compete with ordinary thermal power plants or nuclear power plants.

2) Light-to-electricity direct conversion method This method uses the photoelectric effect to directly convert solar radiation energy into electrical energy. The basic device for light-to-electricity conversion is the solar cell. A solar cell is a device that directly converts sunlight energy into electrical energy due to the photovoltaic effect. It is a semiconductor photodiode. When the sun shines on the photodiode, the photodiode converts the sun's light energy into electrical energy, producing current. When many batteries are connected in series or parallel, a solar cell array with relatively large output power can be formed. Solar cells are a promising new power source with the three major advantages of permanence, cleanliness and flexibility. Solar cells have a long life. As long as the sun exists, solar cells can be invested once and used for a long time. Compared with thermal power generation and nuclear power generation, solar cells will not cause environmental pollution. Solar cells can be large, medium and small, ranging from medium-sized to millions of kilowatts. A power station is as small as a solar battery pack for one household, which is unmatched by other power sources.

Knowing the basic principles, let’s purchase components and understand their applications.

First component procurement: solar panels

Second component procurement: solar charge and discharge controller

The solar controller is suitable for all types of photovoltaic panels and various types of batteries. The MCU (microprocessor controller) has a PMW (pulse wideband modulation) 0~100% variable duty cycle program. According to the battery type and actual charging conditions, it can provide fast and optimal charging voltage and current from the PV panel.

Third component procurement: lead-acid maintenance-free battery

Commonly used charging methods for batteries

1) Constant current charging method. The charging current remains constant during the charging process. It is called constant current charging method, referred to as constant current charging method or equal current charging method. During the charging process, as the battery voltage gradually increases, the charging current gradually decreases. In order to keep the charging current from decreasing due to the increase in the battery terminal voltage, the power supply voltage must be gradually increased during the charging process to maintain the charging current unchanged. This is Charging equipment requires a high degree of automation, and simple charging equipment cannot meet constant current charging requirements. In the constant current charging method, under the maximum allowable charging current of the battery, the larger the charging current, the shorter the charging time. From a time perspective, this method is advantageous. However, if the charging current remains unchanged at the later stage of charging, because most of the current is used for electrolyzing the water, the electrolyte will have too many bubbles and appear to be boiling. This not only consumes electric energy, but also easily causes a large amount of active material on the plate to fall off, causing the temperature to rise. If it rises too high, the plate will bend, the capacity will drop rapidly and it will be scrapped early. Therefore, this charging method is rarely used.

2) Constant voltage charging method. During the charging process, the charging voltage always remains unchanged, which is called constant voltage charging method, referred to as constant voltage charging method or equal voltage charging method. Since the power supply voltage remains constant from the beginning to the later stage of constant voltage charging, the charging current is quite large at the beginning of charging, which greatly exceeds the normal charging current value. However, as charging proceeds, the battery terminal voltage gradually increases and the charging current gradually decreases. When the battery terminal voltage is equal to the charging voltage, the charging current is reduced to a minimum or even zero.

Fourth component procurement: 3000W solar inverter

The solar inverter is a convenient power converter that can convert DC12V/24V/48V power into AC220V alternating current, which is the same as the mains power, for use by general electrical appliances.

For the convenience of some domestic users, some DC appliances, such as laptops, mobile phones, PDAs, etc., do not use their own 220V power supply in the car, but are directly plugged into the cigarette lighter with a simple converter. This is incorrect! It's also dangerous! The voltage of the car battery is unstable, and taking power directly may burn the electrical appliances, and also greatly affect the service life of the electrical appliances, because the original 220V power supply is specially designed by the manufacturer for electrical appliances and has excellent stability. Abroad, you can find a car inverter in the tool box of almost every car, because its role is so great. With it, your car becomes the mains socket board in your home, and you can use it as you like. You can use electrical appliances that you could not use in your car before. It is the first choice product for car enthusiasts in business travel, field work and mobile office.

Features:1) Using advanced dual-CPU microcontroller intelligent control technology, it has the characteristics of high reliability and low failure rate;

2) Pure sine wave output, strong load capacity and wide application range;

3) It has complete protection functions (overload protection, internal over-temperature protection, output short-circuit protection, input under-voltage protection, input over-voltage protection, etc.), which greatly improves the reliability of the product;

4) Small size and light weight. The internal use of CPU centralized control and patch technology makes the size very small and light weight;

5) Intelligent control of the cooling fan, using the CPU to control the working status of the cooling fan, greatly extending the service life of the fan, saving power and improving work efficiency (ordinary models do not have this function);

6) Low working noise and high efficiency

Scope of application:

1) Vehicle and ship equipment series: police vehicles, police cars, medical ambulances, ships, traffic lights, etc.;

2) Industrial equipment series: solar energy, wind power generation, gas discharge lamps, etc.;

3) Office space: computers, printers, copiers, scanners, digital cameras, etc.;

4) Kitchen appliance series: microwave oven, induction cooker, refrigerator, etc.;

5) Household electrical equipment: electric fans, vacuum cleaners, air conditioners, lighting fixtures, etc.;

6) Power tool series: electric saws, drilling machines, stamping machines, air compressors, etc.;