How one 13-year-old is helping solve a huge solar panel limitation

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Jason Chang was sick of his mother asking him to adjust the family's solar-powered Christmas lights to get more sun, so he devised a solution with big potential. The 13-year-old seventh grader at Worcester Academy in Massachusetts created a solar tracker that utilizes water and gravity to move a solar panel without the need for a motor, a sunlight sensor or electricity to power the mechanism.

The prototype was less than $25 and generated about 20 percent more voltage than a stationary panel in outdoor tests, CBS Boston reports. The contraption tackles a basic limitation of fixed solar panels: the inability to change position as the sun moves across the sky. This teenager's bright idea is attracting national attention. Here's how it works. 

Chang's invention is similar to a seesaw. A small solar panel is mounted on a rotating wooden structure, with water dripping into a bucket on one side. The frame tilts the panel throughout the day as the bucket fills, increasing its weight. There's no sensor needed to determine the sun's position, and the drip rate is adjusted to keep the panel tilting at approximately the correct speed.

It's not difficult to get the process started. Simply pull the plug to set the water in motion. However, it took a lot more work to get that flow just right. Chang spent over a year refining the project, jotting down his tests in a notebook and using recycled materials for much of the construction. And while gravity is free of cost, trying to make it work on a schedule takes a little engineering.

The reported 20 percent improvement also needs to be examined. In the outdoor comparisons, Chang's setup was able to generate higher voltage, but that doesn't necessarily translate to a 20 percent increase in power or total energy output. To calculate those gains, current readings and energy measurements over time would be required, but were not included in the report. It's a positive outcome for a student prototype, but not a guarantee to save you 20 percent on your electric bill.

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Using water and gravity to follow the sun isn't entirely new. There are commercial trackers on the market that can move with the sun, but they cost more than fixed units. There are also some build-it-yourself designs similar to Chang's concept. Engineering for Change promotes a SunSaluter rotating solar panel kit with a suggested retail price of $50. That cost doesn't include the panel, battery, and other components. Chang's version offers another inexpensive DIY take on the idea, rather than a commercially ready replacement for existing trackers.

There's a practical reason why most rooftop solar panels aren't designed to move around. Trackers can boost energy yields from ground-mounted arrays, but they also add costs and maintenance. It's easy to tilt a small wooden frame, but mounting moving panels on a roof where they have to withstand wind and rain is where it gets complicated. Any extra electricity would have to be worth the investment and maintenance. Another fixed panel might be a lot less hassle for some homeowners.

Sure, motor-free tracking could still appeal to people running small off-grid systems, where every bit of power counts. However, water has its own set of issues. While cold weather can actually boost solar panel efficiency, a mechanism that relies on flowing water has an unwelcome winter issue: ice, which is why Chang is working on a winter version.

CBS did not say how often the water needs to be refilled, how often the tracker needs to be reset, or whether the design has been tested with full-size panels in strong winds. Regardless, Chang's work as a seventh-grader is exceptional. In 2026, he was one of 55 students recognized as National STEM Champions.