Solar panels only work at maximum capacity during peak sun hours. Peak sun hours vary by latitude and by the seasons of the year. Wouldn’t it be great to have an installation that changes the angle of the solar panels to increase the time the panels are optimally exposed to the sun?
A fixed mounting system is still the most cost-effective method to mount your solar panels. The investment required to install a solar tracking system is very high and can easily double the cost of your solar project. In addition, solar tracking systems consist of moving parts and need maintenance.
Like sunflowers, solar tracking systems follow the movement of the sun to keep the solar panels at an optimum angle, meaning they will produce the maximum power output (watts) for which they are rated. Let’s find out more about both solar systems.
Tracker Vs. Fixed Mount Solar System; Which One is Better?
As the sun’s position, relative to the solar panels, is constantly moving, installing a solar tracking system means that the solar panels will continually track the sun, ensuring they point directly at the sun during the day.
The main downside of solar tracking systems is that they are very costly for only a marginal improvement ineffectiveness. They also require regular maintenance, and that’s why fixed mounts are the best way to mount solar panels.
Closer Look at The Solar Mounting Systems
Solar panel efficiency is affected by:
- Insolation – Insolation measures solar radiation in the earth’s atmosphere or at the earth’s surface (determines energy produced in kWh).
- Irradiance – the sun’s power, expressed in watts, which hit the panel’s surface at any time.
- Temperature – solar panels are most efficient at 77 degrees F (26 degrees C). If the temperature varies, the efficiency of the panel is changed.
- Orientation – direction pointing – due South for Northern hemisphere and visa-versa.
- Tilt angle – location latitude +15 degrees in Winter and -15 degrees in Summer
The panels’ efficiencies, construction, and ongoing cleaning are the best ways to optimize insolation, solar irradiance, and temperature range capabilities.
In a fixed mount system, the orientation and tilt angle of the panels is unchanged; on the other hand, solar tracking systems match the panel’s angle to the sun’s movement from east to west.
There are four types of solar mounting systems:
- Fixed Mount
- Manual Solar Tracking System
- Passive Solar Tracking System
- Active Solar Tracking System
1. Fixed Mount Solar Panel Systems
This method includes both solar panels and solar tiles. While solar tiles are installed as part of the roof, a fixed mount solar panel system typically consists of the solar panels installed directly onto the roof or separate immovable frame.
The position of the panels is fixed and cannot be adjusted once installed.
The Benefits Of A Fixed Mount Solar System Are:
- The mounting systems are low-cost.
- If the installation is not generating sufficient yield, it is a much lower cost option to install more panels.
- A fixed mounted solar system involves no moving parts, so maintenance is significantly reduced.
Cons Of A Fixed Mount Solar System Are:
- If the structure’s roof is not optimally positioned and angled to the sun, it will compromise the solar panels’ effectiveness.
- Fixed-mount solar systems do not track the sun, so the peak sun hour window of a fixed mount solar system is smaller than a solar tracking system.
2. Manual Solar Tracking System
A manual solar tracking system uses a frame on which the solar panels are mounted. This is manually adjusted throughout the day.
- The system is the lowest cost installation of a Solar Tracking System
- As the owner will need someone to “staff” the solar panels and manually reposition them through the day, it is not a generally viable way to track the sun.
3. Passive Solar Tracking System
Passive Solar Tracking systems operate using an ingenious yet simple method:
- The panel mounting is balanced and slightly weighted to the west.
- Passive trackers use a compressed gas fluid that has a low boiling point.
- As the sun heats the gas, it causes pressure to rise, which moves the fluid from side to side.
- In the early morning, the mount has sufficient weight to unbalance the panels and point them to the east.
- During the day, as the sun heats up and the pressure increases, the fluid is moved in a westerly direction, and as the balance of the unit changes and it slowly tilts until the evening when it points to the west.
- As the gas cools at night, the operation is reversed to position the panels for the next day.
- It is simple and requires fewer parts, with no motors or hydraulic systems.
- The only potential failure point is the seals that contain the gas/fluid. Apart from this, it is relatively maintenance-free.
- It costs less than an active tracking solar system.
- No active systems monitor the sun’s position; it is less accurate than an Active Solar Tracking System.
- The morning performance is less effective. The gas takes longer to heat up, so the panels will only start moving later in the day.
- As there is no power used, the system cannot incorporate any monitoring systems that are an integral part of active tracking systems.
- Passive Tracking Systems will not work in low-temperature environments
- A passive solar system cannot adjust the mounting to protect it from high winds or other adverse weather.
4. Active Solar Tracking System
Active Solar Tracking Systems use motors or hydraulic pumping systems to mechanically move the panel’s inch by inch as the sun moves. The system constantly makes minor adjustments to ensure that the solar panels face the sun at an optimal angle.
- This system is very advanced and will achieve the optimum position relative to the sun.
- Active Solar Tracking Systems are supported by technology that enables the user to monitor the system’s effectiveness.
- An active Solar Tracking System incorporates alarms that warn the user when the system is not optimized or not working.
- Active Solar Tracking systems can change the position of the panels to resist the forces of high winds or other adverse weather systems.
- Active Tracking systems are costly, and most often, the increase in yield is lower than the cost.
- They are very costly to install, and the number of moving parts makes them at risk of failing, which may involve expensive repairs.
The Other Variations Of Solar Tracking Systems
All solar tracking systems can be installed as a Single Axis Tracking System or Dual Axis Tracking System.
- Single Axis Tracking Systems are engineered to enable a rotational axis on the east-west movement of the sun; this does not account for changes caused by the season. Single Axis Tracking systems are approximately 10-20% more efficient than fixed-mount solar systems.
- A Dual Axis Tracking System has the same horizontal rotation as a single axis system; however, each panel can also move on a North-South axis to automatically follow the sun’s seasonal variations. Dual Axis Tracking systems are about 15-30% more efficient than single-axis tracking systems.
Cost Of Solar Tracking vs. Fixed Mount Installation
To increase the yield of a solar system, the property owners can either install more panels or install a Solar Tracking System. We make the following assumptions:
- Assuming a 5kw solar system is installed at a property near the equator.
- A solar tracking system may cost between US$500 – US$1,000 per panel.
- Installing 15, 300watt panels would cost approximately US$15,000
- A single-axis solar tracking system would cost around US$500 per panel. That is an additional US$7,500 for the whole system.
- A single-axis Solar Tracking system could increase the yield of the system by 20%.
- For an equivalent increase, the number of solar panels could simply be increased by 20%.
- Therefore, to increase the yield of our solar system, it would cost US$7,500 to install a single-axis tracking system, while it would only cost US$3,000 to add more panels.
Although Solar Tracking Systems incorporate impressive technology and there are many variations in technology to choose from, the cost/benefit ratios are not sufficient to justify compared to a fixed mount system.
I recommend that you opt for more solar panels if you want to improve the power generated by your solar installation system.