solar trackers overview

Solar trackers: everything you need to know

There are many unique ways to design and install a solar energy system for your property in order to utilize solar power. 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: key takeaways

  • 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 compare quotes for customized solar quotes for free

What are 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.

Single-axis vs. dual-axis solar trackers

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

Single-axis solar trackers 

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, increasing the efficiency of your system without having to install more solar panels. Despite their high upfront installation costs and recurring maintenance costs, single-axis solar trackers can increase your solar system’s efficiency enough to quickly make up for your expenses. It’s important to install a single-axis tracking system on flat land in an area that is generally warm and dry. 

Dual-axis solar trackers 

A dual-axis tracker allows your panels to move on two axes, aligned both north-south and east-west. This type of system is designed to maximize your solar energy collection throughout the year by using algorithms and sensors that 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’re located on large plots of land without the tight space constraints of a commercial roof space.

Single-axis vs. dual-axis solar trackers pros and cons

 Single-axis solar tracker Dual-sxis solar tracker
Pros • Typically costs less
• More reliable
• Longer lifespan
• More energy efficient
• More accurate
Cons • Not as energy-efficient
• Not as advanced
• Not as reliable
• Typically more expensive
• Shorter lifespan

Active vs. passive solar trackers

Aside from the difference between single-axis and dual-axis trackers, there are also active and passive solar trackers. The key takeaway: active solar trackers use a motor to move, and passive solar trackers use the sun to move, making them far less advanced in their makeup and function.

Active 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. In general, active solar trackers are more well-suited for large and complex installations.

Passive solar trackers

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. Passive trackers can be used for simple PV systems and not much else, given their lower accuracy. Passive solar trackers are also not as efficient in cold temperatures because the liquid inside the tracker will usually take time to heat up. 

Active vs. passive solar trackers pros and cons

 Active solar tracker Passive solar tracker
Pros • More accurate than passive trackers
• More efficient than passive trackers
• Relies on heat to operate, not energy
• Not as expensive as active trackers
Cons • Needs energy to operate mechanics
• More expensive than passive trackers
• Likely requires more maintenance
• Less accurate than active trackers
• Less efficient than active trackers
• Do not work at low temperature

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. The best orientation and angle for your solar panels depend entirely on where you are on the globe. Learn more about your location and the best angle for your solar panels here.

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. For residential installs, it often isn’t worth the investment. But for commercial installs, such as businesses with limited roof space but a higher power output, the increased efficiency that comes with a solar tracker might be worth the investment.

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.

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 anywhere 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.

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. To get the most out of your solar system, consider purchasing the most efficient solar panels available today.

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.

Are solar trackers worth it? 

For most residential installs, a solar tracker is typically not worth the investment. Solar panels are cheaper now than ever before, and they’re likely to get cheaper. It’s not likely to change. Investing in equipment to continually adjust the orientation of your solar panels ultimately is more money upfront and requires more energy, which just takes away from your household. 

Frequently asked questions about solar tracking systems

Are solar trackers worth it?

For commercial builds, they can be. For residential customers, solar trackers typically aren’t worth the investment due to the cost and relatively small boost in efficiency for a smaller build. 

What is the best solar tracker?

This depends entirely on the situation. In some cases, a dual-axis active tracker may be ideal, but with some builds a single-axis active solar tracker, or a passive solar tracker, might be the best option. In 2019, NEXTracker was the most popular solar tracker seller. 

Are solar trackers expensive?

Typically, solar systems that include solar trackers cost between 40-100% more than a build without them. The price you pay will depend on which type of tracker you purchase and the complexity of your installation, but all solar trackers are made up of moving parts which can mean more maintenance costs. 

How does a solar tracker work?

A solar tracker works by adjusting the angle of solar panels to best optimize solar panels according to the time of day or year. 

What is the most efficient solar tracker?

This depends on several factors: the type of solar tracker, where it’s located, and the size of the solar panel system it is operating.

Is there a solar panel that follows the sun?

Solar panels don’t follow the sun on their own, but with the addition of a solar tracker, you can optimize your system to follow the sun and obtain maximum power output.

What is a disadvantage of using a tracking solar panel?

The biggest disadvantage to solar trackers is the cost. The initial cost can be expensive, and the maintenance costs can also add up. For many commercial builds, though, this is an acceptable cost given that solar trackers can make solar panels up to 45% more efficient. 

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.

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