Bifacial solar energy modules at Solar Energy PV Plant in Atacama Desert.

What Is A Solar Tracker? A Homeowner’s Guide

Oct 3, 2022

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Homeowners with solar panels want to get as much sunlight on them as possible, and solar trackers offer a way to make that happen. Let’s explore this option to see when solar trackers are a good idea for residential photovoltaic (PV) arrays.

What Is A Solar Tracker?

A solar tracker is mounting hardware that allows solar panels to move along with the sun. This can ensure that a PV array soaks up as much solar radiation as possible and turns it into renewable energy to power a home, a business or an electrical grid.

Because the sun moves throughout the day, the best angle for solar panels to capture sunlight changes for most installations. Other factors such as shadows from trees or other buildings can also cause solar modules to receive less of the sun’s rays.

If your property isn’t perfectly suited for a PV array, a solar tracker can minimize this problem by changing the orientation or angle of the modules.

Typically, solar trackers are used for ground-mount solar modules. They may put too much strain on a home’s roof, both from weight and the panels moving in heavy winds.

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Types Of Solar Panel Tracking Systems

A number of options are available for solar trackers, ranging from manual to motorized and single axis to multiple axes. Let’s break down some of the options.

Active Solar Trackers

An active solar tracker uses a motor to move or tilt the PV panel. With the motor comes complexity and cost, so active trackers are typically found in commercial installations.

Single-Axis Solar Trackers

A single-axis tracking system follows the sun by rotating in a single arc. It can move east to west, either by rotating or rolling. Just this single axis can improve power output by 25% – 35%. Single-axis trackers are commonly used for utility-scale PV installations.

Dual-Axis Solar Trackers

With a dual-axis solar tracking system, a module can have a 45% higher increase in energy production than if it’s stationary. Dual-axis tracking can help generate the maximum amount of exposure in a minimum amount of space.

By using software algorithms and sensors, dual-axis trackers track the sun’s position by season. The two axes are often best suited for rooftops on large commercial buildings.

Passive Solar Trackers

A passive solar tracker uses solar radiation to heat a gas, which expands and moves solar panels. When the sun sets and temperatures cool, the gas cools, contracts and allows the panels to move to their original position. Passive trackers are less precise than active systems and not as suited for cold temperatures.

Manual Trackers

Manual trackers allow for a small range of motion. Rather than following the sun throughout the day, they’re intended to maximize the position of solar panels on a seasonal basis. They might be able to add 5% – 15% to your system production.

They’re not very common on residential solar arrays because they require owners to physically tend to the panels.

Are Solar Panels That Follow The Sun Worth The Cost?

Depending on your needs and system size, each tracking module ranges in costs vastly, averaging $500 – $1,000 per module before applying any government and utility company incentives. If you’re researching solar panel system prices, EnergySage suggests adding solar trackers can add 40% – 100% to the cost of a system. That also means potentially doubling the payback period of your solar panels.

For example, the average 6-kilowatt (kW) PV system costs $16,620 before government and utility incentives. To add single-axis solar tracking, let’s assume it was possible to mount three solar panels on one tracker. That might require up to five trackers, which would add $2,500 – $5,000 to the system cost. The extra cost could be even higher if you need a tracker for each individual module.

Your roof would also need to accommodate the weight of the array, or you’d need to have enough space for a ground-mounted system.

For large-scale solar projects on commercial or government properties, tracking systems can pay off. For a homeowner, though, adding energy storage or additional modules to their array might produce a better ROI than trackers to improve solar production.

Pros And Cons Of A Solar Tracker System

The ability of solar trackers to produce so much more energy makes them sound appealing. They offer the potential to generate more power than a fixed solar array with the same number of modules – or to use a smaller array to produce the same amount of power as a static solar installation.

Solar trackers present some major barriers for homeowners, however. These systems could potentially double the cost of installing a PV array, and they may need maintenance. They may also be too heavy to mount on a home’s roof.

Solar trackers also tend to be affected by wind when mounted on roofs. During heavy gusts, they can capture more wind because they’re mounted high above the roof line, causing extra strain on the roof. Below are the advantages and disadvantages of solar trackers.

Pros

Cons

Capture more sunlight than a static array.

More expensive than stationary panels.

May allow you to buy fewer panels.

Require more maintenance and its associated costs.

 

Best suited for ground-mounted solar panels or large commercial rooftop arrays.

 

May require more planning and preparation.


Can You Put A Solar Tracker On A Home’s Roof?

For most homeowners, the expense and difficulty of putting solar trackers on a roof isn’t worth the cost. Solar trackers are more complex systems that cost more to purchase, install and maintain than traditional stationary solar panels.

Even homes with a ground-mounted array might find it more cost-effective to simply orient the array to the south. Adding more solar panels to your array is more likely to produce more energy dollar-for-dollar than establishing a tracking system.

The Bottom Line: Sun-Tracking Solar Panels Aren’t The Solution For Most Homeowners

For most homeowners, solar tracking systems are too great of an expense. They also might be too heavy for a home roof and have extra moving parts. The better route to a faster payback time is to use standard racking on a roof-mounted system. Any extra funds you’d like to put into a roof-mounted system might be better applied to energy storage.

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