Which kind of motor is used in solar tracking system?

What is solar tracking system?

“Solar tracker (Solar tracker motor) a system that positions an object at an angle relative to the Sun.”(Jake Yoshitake) Because the position of the sun constantly changes every day, a fixed solar panel can not be able to maximize the conversion efficiency in a day. That caused a problem which a fixed solar panel will be unable to receive direct sunlight most of the time in a day. So the conversion efficiency of the solar photovoltaic panel is the highest when the sunlight is faced to the solar panel. That is why we have to equip a solar tracking system which could help solar panels move follow the movement of the sun. Through changing the position of the solar panel to achieve the solar panel could face to the sun light directly in days. This machine could improve the solar absorption.

Solar tracking system (Single-Axis)

Solar Energy Market analysis.

In the 21st century, global warming has become an issue of concern to most of governments all over the world. Reducing carbon emissions is one of an international consensus on solving the problem of global warming. Hence, Development and utilization of new renewable energy (Solar, Wind, etc.) is an important trend in the future.

According to the report from SolarPower Europe “ A massive 138.2 GW of solar was installed in 2020, representing an 18% increase compared to 2019. Another significant milestone from 2020 was the fact that the global cumulative solar capacity reached 773.2GW, exceeding three quarters of a terawatt for the first time ever” (Solar Power Europe) Therefore, we have reason to believe that more and more countries are gradually deploying solar energy equipment, and the solar energy market is bound to develop rapidly in the next ten years.

Which kind of motor are used in solar tracking system(Solar tracker motor)?

There are 3 kinds of motor working for solar tracking system in the market including AC motor, DC motor , BLDC motor. All of them have their own advantages and disadvantages.

AC motor: AC induction motors have been used on a large scale in solar tracking systems in the early days of the development of solar equipment. The driving voltage of the AC motor is 220V. This volatge can obtain energy directly from the grid without additional batteries. This is one of the AC motor’s advantages. However, AC motor is hard to control compare wtih other motors. In the solar tracking system, the control of the motor is an important facotor. The AC motor will greatly reduce the efficiency of solar energy conversion. Therefore, the AC motor has gradually withdrawn from the mainstream market of solar tracking system.

PMDC Motor: The cheap and efficient PMDC motor is currently the most popular solar tracking motor(DC GEAR MOTOR, DC PLANETARY GEAR MOTOR) on the market. PMDC motor could be controlled easily by controller. However, the disadvantage for the PMDC motor is life of carbon brush. Conventional PMDC motors can only last 3000-5000 hours of working time due to the limited life of carbon brushes which means the solar tracking system have to replace the motor within a period of time.

BLDC Motor: Compare with the PMDC motor, BLDC motor. The feature of BLDC motor that does not require carbon brushes can greatly extend the working life of the motor. Maintenance-free and high efficiency are the main two reasons why BLDC motors can occupy the solar tracker market.

Which gearbox applied on Solar tracking motor?

Industrial solar tracking system requires a huge torque to rotate large-area solar panels, which means that solar tracking motors need the cooperation of a gearbox to achieve high-torque and low-speed control.

Compare with the spur gearbox and harmonic gearbox,  The advantages of planetary gear motors are high efficiency, low cost, high adaptability.

Here are two main planetary gear motor which applied on the solar tracking system market.

PG-80 Solar tracker Motor

One of most popular Solar tracking motor PG-80(DONCENMOTOR

This motor is 80mm 48V BLDC motor with 120mm planetary gearbox which could output 290N.m with 2 rpm at working point. The large torque means it could afford more solar panels with a single motor. That is why this kind of motors are widely used on single-axis solar trackers. Another advantage of this motor is long working life. After testing, this motor can work continuously for more than 20000 hours. The life of this motor decided by the life of bearing. This motor could working until the bearing wear out.

Another solar tracking motor widely used in the solar tracking market is the motor which has 56mm 24V DC motor with 56mm planetary gearbox.

PG-56 Serie

It could output around 50-100W with relatively high torque. The mainstream solar tracking systems on the market are using this type of geared motor. Because of power constraints, PG56 series can output a limited amount of torque. But the advantage of PG56 is the small size with cheap price. The low price and stable control make this motor widely used in double=axis solar trackers. Usually engineers will use two or four PG56 in a system to get more torque.

The forecast of Solar trackers’ motor market

Global warming issues are forcing governments and organizations to find new, clean, renewable energy sources to replace the traditional energy. Solar power generation must be one of the main energy channels for future social development. In order to improve the utilization of solar energy, the demand for solar trackers will definitely increase year by year. This means that the market for solar tracker motors will also grow together. Although there are still many limitations and applicability problems of solar energy equipment at this stage. The market prospect of solar energy has certain possibility and room for improvement.

Work Cites:

https://www.reneqsupply.com/products/trackers

https://www.britannica.com/technology/solar-tracker