The solar tracking energy system is a control device used to assist photovoltaic modules to accurately track solar energy and improve solar energy utilization.
If the angle between the power generation system and the sun rays deviates by 25°, the photovoltaic array output power will decrease by about 10%. This is due to the reduction in vertically incident radiant energy.
We can obtain accurate conversion efficiency and greater investment returns by tracking the sun with high precision and stability.
The solar tracking energy system improves the power generation efficiency of photovoltaic power generation using solar energy. It is also widely used in the photovoltaic industry because it adapts to complex terrain and local conditions.
A properly designed solar tracking energy system can increase overall efficiency by more than 40%.
How do solar tracking energy systems work?
Its working principle is to optimize the angle between sunlight and electronic components as much as possible.
By tracking the sun’s movement in real-time, sun’s rays are directed toward the photovoltaic array. This increases the amount of solar radiation received by the photovoltaic array. This increases the overall power generation of the solar photovoltaic power generation system.
The generally adopted tracking control strategy is the active tracking control strategy, which uses two basic tracking control methods.
The first way is light control, using a light sensor. Based on the difference in brightness intensity in different areas of the sky, the sun’s position is determined. The motor rotates the bracket for tracking.
The sensor is installed on the solar panel array and operates synchronously with it. Once the light direction changes slightly, the sensor will be unbalanced and the system’s output signal will deviate.
When the deviation reaches a certain amplitude, the sensor outputs a corresponding signal. The execution system will correct the deviation to bring the photoelectric sensor back into balance.
That is, when the plane of the solar panel array controlled by the sensor output signal is at right angles to the light, it stops rotating. It completes an adjustment cycle.
Such constant adjustments always follow the sun’s trajectory, forming a closed-circuit feedback system to achieve automatic tracking.
The second method is time control, which uses astronomical calculation formulas to calculate the coordinates of the sun in the sky based on the local latitude and longitude coordinates and time, and then drives the motor to rotate the bracket for tracking.
In time control mode, the GPS module can be used to obtain local longitude, latitude, and time. This will ensure the accuracy of coordinates and time, improving tracking accuracy.
You can also combine the two control methods
1 – Use time control most of the time, supplemented with light control. When the weather is favorable, use time controls to track the approximate sun position.
Use light controls for precise adjustment. When weather conditions are adverse, utilize time control alone for tracking to avoid interference from stray lights in the sky.
2 – Switch between light control and time control, that is, when the weather is pleasant, use light control alone for tracking.
If it encounters rainy weather, it will automatically switch to time control mode for tracking.
Artificial intelligence technology is now applied to solar tracking energy systems. Smart panel sensors are installed at the end of each solar panel to provide real-time shading information.
It is then processed by machine learning algorithms that build virtual 3D models. Taking real-time power generation as the condition of the controller, solar power plant power is maximized through a series of algorithms.
In terms of function, the solar tracking energy system also has a rainy-day cleaning mode, a heavy snow and hail protection mode, and a strong wind protection mode.
Rainy day cleaning mode, through background control, allows the tracking bracket to rotate several times from -50° to +50° of the component. Use rainwater to flush the bracket.
The heavy snow and hail protection mode allows the modules to rotate to the optimal tilt angle to avoid the direct impact of hail and prevent snow from covering the modules.
High wind protection mode can achieve wind resistance performance of 55.6m/s in the maximum safety state.
Therefore, the solar tracking energy system is better suited to environments with frost, snow, and dust.
It can also work reliably in unattended photovoltaic power plants.
From the perspective of continuous monitoring, solar tracking energy systems mostly use step tracking methods.
Compared with the continuous tracking method, the step tracking method can greatly reduce the energy consumption of the tracking system itself.
A manual control switch will also be included to facilitate debugging.
Now that you know this much, can you make your solar tracking energy system?
How to make an advanced solar tracking energy system?
PVMars recorded a video, about 8 minutes long, using a miniature solar tracking energy system as an example.
It is not as powerful as those installed in homes, industries, and commerce.
But it can provide a high-efficiency charging solution using solar power and other power supply methods when you cannot obtain stable power in the wild.
Production principle:
Let the two photoresistor modules be in two relatively independent grids on the left and right. Read the module’s analog output value of light intensity in real-time.
When sunlight shines vertically on the isolation plate in the middle of the photoresistor module, it shines vertically on the solar panel.
The analog output values of the two photoresistor modules are equal. When the value on one side is significantly greater than the value on the other side, it can be considered that sunlight is deflected to that side.
Then the steering gear at the bottom of the solar panel is driven to turn until the sun shines directly again.
To read the analog output value of the photoresistor module, call the analog reading block of the microbit’s P3 and P4 pins.
Then use the logical judgment building blocks to judge the output values of the two photoresistor modules. This will cause the steering gear to rotate.
Hardware connection:
Servo: brown wire –> expansion board GND red wire –> expansion board +5V orange wire –> expansion board P1.
Photoresistor module 1: VCC–>Extension board +3.3V GND–>Extension board GND AO–>Extension board P3
Photoresistor module 2: VCC–>Extension board +3.3V GND–>Extension board GND AO–>Extension board P4
Before making a solar tracking energy system, you also need to purchase some hardware: solar panels, photoresistor modules, VCC, expansion boards, etc.
Following the video instructions, you can also become an engineer making solar tracking energy systems. Also, do you know what type of tracking system the video uses?
Classification of solar tracking energy systems
It can be divided into dual-axis tracking, flat single-axis tracking, flat single-axis tracking with tilt angle, oblique single-axis tracking, etc.
Using different tracking systems can increase power generation by 10% to 45%.
According to whether it is linked or not, it can be divided into single axis without linkage, multi-row linkage, and double-row linkage
What is a dual-axis solar tracking system?
The photovoltaic bracket rotates around a two-dimensional axis (vertical axis, horizontal axis) to achieve two degrees of rotational freedom.
Taking the ground plane as the reference system, the tracking target is the solar altitude and azimuth angle.
This is so that the light-receiving surface of the photovoltaic module is always perpendicular to the sunlight incident direction.
That is, the sun’s incident angle is always zero within the tracking range, maximizing sunlight resources.
What is a flat single-axis tracking system?
The rotating axis of the photovoltaic bracket is installed parallel to the horizontal plane and rotates around a one-dimensional axis, with the rotation axis running north-south.
The basic principle of operation is to ensure that the solar panels are at right angles to the sun’s rays in the east-west direction.
So a flat single-axis tracker tracks the azimuth angle of the sun, not the altitude angle.
For flat single-axis tracking systems, if inverse tracking technology is used, array spacing can be reduced while leaving no obstruction between photovoltaic arrays.
What is a flat single-axis linkage tracking system?
Multiple photovoltaic arrays installed on a flat single axis are spaced at a certain distance and connected horizontally into one.
A tracking system that simultaneously rotates around a one-dimensional axis so that the light-receiving surfaces of all photovoltaic modules are as perpendicular to the incident angle of sunlight as possible in a one-dimensional direction.
The tracking system in our previous video was a flat single-axis tracking system.
Since there are so many types, which one should I choose? Which tracking system is right for you?
Application scenarios for solar tracking energy systems
Let’s take latitude as an example:
In low latitude areas (0°-30°), the sun’s altitude angle is relatively high, so solar panels are suitable for horizontal placement, which can significantly increase power generation.
At high latitudes (60°-90°), the sun’s altitude angle is relatively low, so solar panels are suitable for tilted placement.
Mid- and low-latitude areas (near the equator): flat uniaxial tracking systems with inclination.
Middle and high latitudes (30°-60° away from the equator): the use of oblique single-axis, single-column dual-axis, flat single-axis with tilt angle, single-column oblique single-axis tracking system.
Dual-axis solar systems can increase power generation efficiency by 40%.
However, the bracket costs are high, and the land resources occupied are two or three times that of the fixed bracket.
The initial investment cost is very high, and its application scenarios are limited due to its complex structure, cost, failure rate, and other issues.
The inclined single axis is between the flat single axis and the double axis.
For the bracket investment cost and land use occupation are about twice that of the flat single axis.
The reliability risk of the flat single-axis is lower than that of the inclined single-axis and double-axis, and it has the advantages of low cost, simple installation, and low maintenance costs.
Therefore, it has the best cost-effectiveness and is widely adopted around the world.
Precautions:
The solar tracking energy system solves stability and accuracy.
Both the pan and tilt are driven by a rotary reducer. This avoids the shortcomings of the rubber telescopic sheath tube of the electric push rod being easily damaged and having low impact resistance.
Designing the rotation center and the module’s center of mass at the same point or similar points greatly reduces pitching transmission torque.
As a result, a smaller rotary reducer can be used to drive. This reduces costs, saving electricity, reducing wear and tear on machine parts, and giving the rotary reducer a longer service life.
The protection level of the driving mechanism of the photovoltaic automatic tracking system generally reaches IP55.
The drive motor should be a DC motor with large starting torque, strong overload capacity, and suitable for intermittent operation. Generally, IP65 protection should be sufficient.
The increase in area and weight of solar panels puts higher requirements on tracking brackets.
Static mechanical bearing capacity and dynamic operational stability need to be considered to make the structure more reliable.
Pay attention to construction deviations and uneven settlement, which are often the main factors causing damage to the tracking bracket.
These factors require a certain degree of foundation settlement adaptability.
Solar tracking energy systems require wind tunnel testing of wind-induced stability.
Designed for different strength brackets on the periphery of the square array to improve wind resistance.
The aerodynamic stability analysis of the photovoltaic automatic tracking system needs to ensure that the vortex vibration is stable within a certain amplitude range at small wind speeds. It does not become fluttery at high wind speeds.
While ensuring efficacy, the number and weight of each MW photovoltaic automatic tracking system pile should be reduced as much as possible.
