The sun`s trajectory is a factor of time of day, geographical location and season. The goal of all solar trackers (some more sophisticated than others) is to follow the sun`s trajectory and ensure that the solar panels are positioned for maximum exposure to sunlight.
We seldom see solar trackers in residential applications. Are solar tracking systems really necessary for homeowners?
Solar trackers significantly improve performance
The companies that sell solar trackers are claiming an increase of 25-45% in power output compared to fixed-tilt solar systems (e.g. rooftop installations). No wonder why solar trackers were used in more than 85% of all commercial photovoltaic (PV) installations larger than 1MW between 2009 and 2012.
Improved performance in terms of higher power output is another way of saying better space-efficiency.
In one sense, a solar tracking system that improves efficiency by 30% would be the equivalent to solar panels with a 30% higher efficiency rating. Likewise, the same increase in performance can be obtained by making the system 30% larger (add more solar panels).
Which type of solar tracker is the best?
There are single and double-axis solar trackers. We typically see a performance gain of 25-35% with single-axis solar trackers. With double-axis solar trackers, performance goes up additionally 5-10%.
We also separate between active and passive solar trackers. We have to feed active solar trackers with energy (i.e. electricity) because they are reliant on motors, gear trains or hydraulics. Passive solar trackers are based on compressed fluids with low boiling points, and run purely on solar energy, but are less accurate.
Increased complexity inevitably introduces additional possibilities for malfunction and failure. For most homeowners, simplicity will yield the highest long-term savings. The extra performance gain of double-axis solar trackers is typically not worth it.
Are solar trackers worth the extra costs and maintenance?
In large-scale applications, regular maintenance is necessary for performance to stay consistent. Residential solar trackers generally require little maintenance, but failures occasionally happen.
If you`ve got limited space, and you`re looking to make the most out of it, solar tracking could be wise. However, for most homeowners it all comes down to long-term savings. Does the performance gain from the solar trackers justify the additional costs? Maybe the money is better spent on extra solar panels? Don’t forget that most solar trackers consume power. There may also be local regulations that forbid the use of solar trackers.