What do solar trackers do? What are their limitations and ultimately are they worth the investment in the UK?
In this guide we will cover the various pros and cons of solar trackers, their limitations and costs, so that you can make an informed decision whether or not to include them in your solar array installation.
Please note: solar trackers are typically not used for domestic roof installs, they are too heavy and costly and so are mostly used in the context of commercial solar installs.
What are Solar Trackers?
As their name implies, solar trackers help your solar panels track the movements of the sun during the day, helping to maximise the amount of sun that hits them and therefore maximise the power generation.
A solar tracker is able to tilt and change the angle of the solar panels for ground mounted solar arrays.
Typically, solar trackers are not used for residential ground mounted installs.
This is largely due to the costs involved, as well as the added maintenance they require, making them more suitable and common in commercial solar set-ups.
How do solar trackers work?
As discussed, a solar tracker tracks the movement of the sun and adjusts the solar panels, so that the sunlight rays maintain a perpendicular angle to maximise energy production.
This is in contrast to regular solar array installs that do not move, in which case the sunlight hits the panels at varying angles throughout the day.
The angle at which the sunlight hits the panels is referred to as the angle of incidence.
Essentially, the narrower the angle of incidence, the more power is generated.
Therefore by keeping the solar panels tracking the sun, they are perpendicular to it and so are able to output more energy.
The Technical Details
Solar trackers themselves can use two main types of technology to track the movement of the sun throughout the day, these include the following:
- Software that follows a pre-programmed map throughout the day.
- Solar sensors that are able to detect the movement of the sun.
Although the latter reacts to the sun in real time, it is less reliable in times of cloud or at dawn when the sun is less visible in the sky.
Types of Solar Trackers
The two major types of solar trackers are categorised based on their ability to move in either a single or dual axis.
Single axis solar trackers are able to move on a north-south axis.
For example, this means that during the day they will tilt in the direction of the sun from an east to west orientation in order to follow the sun.
The second type of solar tracker is the dual axis type, which are able to move in two orientations.
For example, one axis will work as above, but the second axis has a east-west orientation enabling the solar panels to change the angle north to south.
This enables the solar panels to maximise output during different seasons, for example, when the suns angle changes relative to the solar panels due to the time of year.
Are Solar Trackers Worth It?
For commercial ground mounted solar arrays, there is no doubt that a solar tracker is well worth the investment.
In terms of numbers, installing a solar tracker with a single axis can increase output by as much as 25%.
While installing a solar tracker with dual axis can increase output up to an additional 10%.
However, solar trackers are not used in residential solar panel installs.
Solar trackers are extremely heavy and are not designed or suitable for domestic roofs.
They are also extremely costly and since they have moving parts and use software, they take a lot of maintenance.
For this reason, solar trackers are usually only employed in large commercial solar farms where the added expense makes financial sense.