Everything About Solar Tracking [Complete Guide]
Solar tracking is a technology that tracks the movement of the sun. When you have fixed solar panels installed on your home, they are typically facing in one direction.
Tracking panels on the other hand are able to rotate and follow the path of the sun.
This means that they can generate more energy than fixed solar panel systems because they will be angled towards the sun throughout their journey across the sky.
Then the question becomes if it is so good to have tracking panels, why aren’t all solar panel systems on homes designed to track the sun?
The answer is that this technology does come with some challenges. It can add considerable cost and installation time (and therefore money) compared to fixed solar panel systems.
Solar tracking doesn't worth the investment anymore for most residential PV arrays since solar panels are getting cheaper as the technology advances.
The prices of solar panels have come down so much in recent years that it is now cheaper for homeowners to purchase and install new panels than rather than investing in a tracking system.
Fixed systems are less complicated and easier to install and maintain for most residential solar energy systems.
But as with everything, there is always another side to the story. There are certain applications where solar tracking is still a worthy investment. For example, utility-scale solar energy systems are still greatly benefiting from this technology.
Since these systems can generate massive amounts of energy, even a small increase in their productivity can have a huge impact on the overall energy output of the project.
It is very common to see a 20% or more increase in energy output using a solar tracking system for a utility-scale project.
This makes solar tracking very valuable for commercial energy production projects and therefore is still an option worth investing in, even if it comes at a higher cost than fixed panel installations.
Another application where solar tracking systems are valuable is where there is a mismatch between energy supply and demand.
Many off-grid homes and communities find themselves in this situation, where they need to rely on their own energy sources due to not having access to the grid.
Let's face it, storing energy is expensive and inefficient for a lot of solar PV system owners. Even almost all off-grid projects have batteries to store any excess energy for use when needed, the amount of energy that can be stored may be limited due to high initial battery costs.
The comfort of generating your own energy consistently is also something that is appealing to many off-grid system owners.
Therefore, solar tracking is a great solution because it not only increases energy production but also minimizes the need for additional batteries to store extra energy while offering some level of energy security.
What to look for deciding whether solar tracking is right for you?
Solar tracking serves a goal and responds to a need, so before deciding if this system is right for you it’s important to ask yourself what your needs are.
There isn't a one-size-fits-all answer with solar tracking systems because the benefits offered by these types of PV panels depend on several factors such as:
The size of your PV system
The size of your PV system will play a major role in dictating whether or not you should choose solar tracking.
Since it requires more components and materials, larger systems will benefit most from the addition of tracking technology while smaller systems may be just fine with fixed panels.
If you have a grid-tied residential solar PV system you most likely won’t need solar tracking.
Price of electricity (and time-based pricing information)
Electricity rates are variable and they change depending on the time of day, season, or other factors.
If you can find out your current electricity prices then this information will be extremely useful when making a decision about whether to go with fixed panels or solar tracking.
Because the amount of money that you save every month after installation will depend on your current electricity prices, it is important to research them before making any investments.
Daily & yearly energy use patterns
Knowing daily and yearly energy use patterns will also help you with deciding whether or not solar tracking is worth it.
This information can be found in your electric bill and using software that matches up historical electricity prices to the generated energy data from your system can determine how much money you save each month because of a certain configuration (tracking, fixed, etc).
Availability of grid backup (Grid-tied / Off-grid system)
If you have access to grid backup power then the urgency for solar tracking is eliminated since you can rely on traditional grid energy when there is no sun.
Off-grid systems are completely isolated from the grid and can benefit from solar tracking since they need to generate all of their own power.
Available battery storage
One big advantage of solar tracking is having the ability to generate additional power during the day without mostly relying on battery storage.
This can be beneficial for systems that have limited battery storage and require a buffer of solar energy to charge batteries during the day so there is enough power available at night when it’s dark out.
The amount of available space
Available space is another important factor to consider and can be by itself one of the biggest challenges when deciding between fixed panels and solar tracking.
Tracking systems may need a good amount of unobstructed space to be able to rotate fully and not hit anything.
If there is a lack of space then it may be better to use fixed panels instead since they don’t require any additional space to function properly.
On homes where there is limited roof space, going with solar tracking may not be possible regardless of the benefits that come along with it.
In order for you to make an informed decision about what configuration will work best for your house, you may need to carefully calculate the amount of available space you have.
The presence of shading on the roof
Shading is another important factor to consider because it can lower your system’s energy production capabilities by restricting access to sunlight that falls onto your panels.
Although tracking systems are able to move with the sun, they still need unobstructed paths along which their solar panels can rotate.
The age of your system and future plans for expansion
If you don’t see yourself expanding or upgrading to a bigger system anytime soon then solar tracking might not be worth it since there could always be something better and cheaper that comes along.
For those who are looking to make a long-term investment, solar tracking may be the way to go as it will increase productivity from day one and might pay off in the future when you need more energy production capabilities.
The cost of purchase, installation & maintenance of the system
As we have discussed, solar tracking comes with some additional costs and challenges. These need to be taken into account when making the decision whether to go for a fixed or tracking system.
Tracking panels will obviously yield more energy than fixed systems, but this increase in power output may not justify the investment if you are currently on-grid or have access to other sources of power.
In conclusion, deciding whether or not solar tracking is worth it depends on the specific circumstances of each household and how much money you can save with a certain configuration.
If you have access to grid backup power then going for a fixed system will give you a lot more flexibility in terms of where your panels are placed while still allowing some room for energy generation.
However, if you have no access to grid backup then going off-grid and taking advantage of solar tracking will be beneficial for your energy needs since you can generate more power than with a fixed system without relying as heavily on battery storage.
If the cost of installation is not an issue for you and your house meets the technical requirements for a solar tracking system, then solar tracking may be worth going with.
When it comes to larger PV plants the question is not whether or not a tracking system should be used.
But the question is rather what kind of tracking system should be used since tracking is very essential for a higher energy yield and can make a big difference in the energy production of a PV plant.
Types of Solar Trackers Based On Drive Types
The passive solar trackers operate on fundamental thermohydraulic principles. It is made up of two tube tanks that are mounted to the side of the PV panel. The operating principle is not as complicated as that of active trackers that we will mention.
When the PV panel is not facing the sun, the fluid (low boiling point compressed gas fluid) inside the tube tank heats up, causing uneven pressure within the tube.
This pressure causes the fluid to migrate from one side of the tube to the other, causing the PV panel to move towards the sun.
Active trackers use a motor to drive the solar panel to follow the sun across the sky. It is equipped with a gearbox and a motor controller to drive the trackers.
Trackers use sensors to determine the location of the sun and can be programmed to track it throughout the day.
During sunrise, the panel moves towards the east at an angle to maximize the sunlight that will fall on it.
At noon, when the sun is at its highest point in the sky, solar panels are usually pointed directly at it. The panel then turns to the west and tracks the sun as it sets in the afternoon, thus maximizing exposure of PV panels before the sun goes down.
Although active trackers are more costly than their passive counterparts, they can save money by generating extra energy (from increased sunlight) throughout the day.
There are also trackers that use solar maps to assist in maximizing energy output. These maps give information about the sun's inclination and azimuth throughout the year in a specific location, which is then used to set up an array of solar panels accordingly.
There are also active tracking systems that combine sensors and solar mapping to track the sun.
Sensors can provide accurate information of the sun's location during sunny days. Whereas solar maps can help on cloudy days to determine the position that guarantees the highest efficiency.
Types of Solar Trackers Based on Axis Number
Single-axis solar trackers rotate on a single axis, which is either north-south or east-west.
They are the simplest type of tracking system and are useful if you want to maximize your solar energy potential in a simple way, without spending too much money.
These trackers can generate 20% – 25% more energy than solar panels without trackers.
There are different types of single-axis solar trackers including:
Horizontal Single-Axis Solar Tracker (HSAT)
HSAT rotates from east to west on a fixed axis parallel to the ground throughout the day, and it is widely regarded as the most cost-effective tracker design in many PV applications.
The HSAT structure is supported by several supports along the rotating axis, requires less material to build, and is favored over alternative tracking geometries due to its horizontal arrangement.
Horizontal Tilted Single-Axis Solar Tracker (HTSAT)
HTSAT trackers are quite similar to the HSAT trackers. However, they are positioned at a different angles.
They are more sophisticated and expensive than horizontal one-axis trackers. They necessitate a concrete foundation, which raises the overall cost, and they are not considered to be scalable.
Vertical Single-Axis Solar Tracker (VSAT)
These systems can be installed in either a north/south or east/west orientation to track the sun's “up-and-down” movement in the sky. These are more common in high-altitude/mountainous areas or in more severe latitudes.
Vertical-Tilted Single-Axis Solar Tracker (VTSAT)
These are similar to HTSATs in that the tilt is horizontal and rotates on a vertical axis. When compared to horizontal trackers, these trackers produce more energy.
However, because of their tilt, they are vulnerable to higher wind loads than horizontal units. They also have high structural demand, needing the use of additional concrete and steel in order to establish a robust base.
Dual-axis trackers have two degrees of rotation: azimuth (which allows the panel to move in a circular route parallel to the surface) and horizontal (also known as elevation angle rotation) (which allows the panel to move up and down ).
The main advantage that comes with this kind of system is that you can track the sun in two different directions. In this case, you will be able to generate up to 30% – 40% more energy from your solar panels.
The main disadvantage is that the dual-axis tracker costs more to purchase and install. These trackers are also more complicated to install and maintain because they contain more moving parts.
How much energy is consumed for tracking, and how does this compare to the energy generated?
The solar tracker rotates a half revolution during the day. It accomplishes this in small increments. It returns to its original position overnight.
On a daily basis, the rooftop carousel consumes 6 Wh and generates 6 kWh of electricity. As a result, the energy required is 0.1% of the energy generated every day.
How about the reliability and maintenance costs of solar trackers?
Today, almost every home has motorized appliances. Washing machines and refrigerators and even the fans in the house are all powered by electricity.
As a result, there is no need to worry about the reliability of solar trackers. They have been in use for quite a while now, and they are quite reliable.
Solar trackers spin at a rate of one revolution per day, which means they only make 7300 revolutions in 20 years.
This number is much less than the number of revolutions other devices such as washing machines make in their generally shorter lifespan. As a result, they are reliable and do not need a lot of maintenance.