solar trackers overview

Solar trackers: everything you need to know

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There are many unique ways to design and install a solar energy system for your property. If you are considering a ground-mounted solar panel installation, you might be considering a solar tracking system so that your panels follow the sun across the sky. This article will examine what installing a solar tracker means and if a tracking system is right for your solar project.

What to know about solar trackers

  • Solar trackers help maximize solar production by following the sun throughout the day
  • Solar trackers are usually used in commercial installations or other large ground-mounted arrays
  • Join the EnergySage Marketplace today to freely compare quotes for customized solar quotes

What are solar trackers? Single-axis vs. dual-axis solar trackers

A solar tracking system maximizes your solar system’s electricity production by moving your panels to follow the sun throughout the day, which optimizes the angle at which your panels receive solar radiation. Solar trackers are typically used for ground-mounted solar panels and large, free-standing solar installations like solar trees. They are typically not used in most residential solar projects, but have a place in the utility-scale and commercial/industrial solar market.

When solar panels are exposed to sunlight, the angle at which the sun’s rays meet the surface of the solar panel (known as the “angle of incidence”) determines how well the panel can convert the incoming light into electricity. The narrower the angle of incidence, the more energy a photovoltaic panel can produce. Solar trackers help to minimize this angle by working to orient panels so that light strikes them perpendicular to their surface.

There are two types of solar tracking systems: single-axis and dual-axis.

  • A single-axis tracker moves your panels on one axis of movement, usually aligned with north and south. These setups allow your panels to arc from east to west and track the sun as it rises and sets.
  • A dual-axis tracker allows your panels to move on two axes, aligned both north-south and an east-west. This type of system is designed to maximize your solar energy collection throughout the year. It can track seasonal variations in the height of the sun in addition to normal daily motion.

Typically, dual-axis trackers (made by companies like AllEarth Renewables) are a much less popular option for solar installations, even among large, utility-scale projects. A situation where dual-axis trackers may be appropriate would be on some commercial properties – due to limited commercial rooftop space for solar panels to be installed, dual-axis trackers that can produce up to 45% more energy than typical static panels can help businesses produce enough power to fuel their operations in a small space. Utility-scale installations usually don’t need dual-axis setups, because they are located on large plots of land without the tight space constraints of a commercial roof space.

Active vs. passive solar trackers

Aside from the difference between single-axis and dual-axis trackers, there are also active and passive solar trackers. Most tracking systems out there are active systems – this means that the tracking system is provided with energy to run a motor or other mechanical device that tilts the attached solar panels the right way. On the other hand, passive solar trackers also track the sun, but without any added energy source. They move by using the heat from the sun to warm a gas. When that gas expands, it causes a mechanical movement of the solar panels. When the sun moves and the gas cools, it compresses again and the panels move back. The actual science behind passive solar trackers is more complicated than this description, but we’ll stay simple for now. The key takeaway: active solar trackers use a motor to move, and passive solar trackers use the sun to move.

In general, active solar trackers are more well-suited for large and complex installations, while passive trackers can be used for simple PV systems and not much else, given their lower accuracy.

How much do solar trackers cost?

It’s tricky to give an exact number for the cost of solar trackers, mostly because most installations that involve trackers are highly customized. Adding trackers to a rooftop system might add any where from 40% to 100% to your total costs, depending on the size of the system, the type of trackers you’re using, and the difficulty of installation.

Benefits and drawbacks of solar trackers

As with any addition to a solar panel system, there are pros and cons to solar trackers.

Pros of solar trackers

At a high level, here are the advantages of solar trackers:

  • Solar panels on tracking systems generate more electricity
  • More electricity production is especially helpful if you’re on a variable electricity rate plan (like time-of-use)
  • More electricity production means you need fewer panels, so you don’t need as much space for your solar setup

The biggest benefit of a solar tracking system is that it offers a boost in electricity production. Generally, a solar panel system with a single-axis solar tracker installed sees a performance gain of 25 to 35 percent. A dual-axis tracker bumps performance up by another five to 10 percent.

If you live in a high latitude where the sun’s position in the sky varies dramatically between summer and winter months, a dual-axis tracking system may be a good way to maximize your solar production and collect enough power for your home or property.

Cons of solar trackers

However, there are some disadvantages of having a solar tracking system:

  • Solar tracking systems cost more money than standard fixed solar panel systems. This is because of both the additional parts needed and added labor to prepare a site for trackers.
  • Oftentimes, solar trackers require more maintenance than fixed-mount solar panels (which need almost no maintenance to begin with)
  • Trackers are often too large and heavy to be used on rooftops, so you’ll have to install a ground-mounted system

Tracking systems tend to have higher installation and maintenance costs. A solar tracker will cost more money upfront than a fixed solar panel system because it is a more complex technology and has moving parts.  This also leads to the second area of increased cost for solar tracking systems: maintenance. With a more complex system comes more maintenance, which can add up in cost over time.

Another disadvantage of a solar tracker is that they are typically too heavy to be used in rooftop solar projects. If you want a solar panel system that has tracking features, be prepared to install a ground-mounted array.

Is a solar tracking system right for you?

A rooftop installation offers lower costs and doesn’t require dedicated yard space, making it the preferable option for most solar-interested homeowners. As a result, most home solar systems don’t include solar trackers – and they’re probably not worth it. If you have a south-facing roof, your solar panels will already be oriented to capture maximum sunlight, which reduces the need for a tracking system.

Solar trackers offer the greatest value proposition in high latitude locations due to the yearly movements of the sun. For this reason, solar customers in Alaska and some northern parts of the contiguous U.S. may want to look into including trackers with their system. However, for the majority of US residents, the sun’s movement will not impact your panel production to the point where a tracking system offers significant financial benefits. Most customers are better off installing a rooftop array on a south-facing surface, or a fixed ground mounted system facing south.

Solar tracking systems are also often used in large commercial projects, typically over 1 megawatt (MW). For commercial-scale solar arrays, the long-term benefit of increased production over time is enough to make the initial cost and maintenance fees worth it. Additionally, commercial-scale solar projects are typically ground mounted, making solar trackers a possibility.

Find the right solar setup for your property

Whether you want a ground-mounted solar array with solar trackers or a rooftop system, it is always important to compare your options before moving forward. On the EnergySage Solar Marketplace, you can solicit quotes for both ground-mounted and rooftop solar projects from qualified, pre-vetted installers in your area. If you are interested in a tracking system, simply leave a note on your profile that you would like quotes including solar trackers.

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About Jacob Marsh

Jacob is a researcher and content writer at EnergySage, where he focuses primarily on current issues–and new technology!–in the solar industry. With a background in environmental and geological science, Jacob brings an analytical perspective and passion for conservation to help solar shoppers make the right energy choices for their wallet and the environment. Outside of EnergySage, you can find him playing Ultimate Frisbee or learning a new, obscure board game.

9 thoughts on “Solar trackers: everything you need to know

  1. Chuck Bever

    My question is : What is the efficiency gained by have the panels perpendicular to the sun on a seasonal basis? I just had such a system installed and found that I can re-tilt the entire 24Kw array in 25 minutes so my plan is to adjust it every 3-5 weeks during the entire year. I’m at the 46th parallel in Minnesota so how can I figure the increase in increased wattage over a fixed array tilted at 46 degrees?


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