Harvesting Energy from the Environment: Meet the Winners of the 2026 Green Powered Challenge

Introduction: A Call for Sustainable Self-Powered Hacks

The 2026 Green Powered Challenge, sponsored by DigiKey, invited makers and engineers to showcase projects that draw power sustainably from their surroundings. The goal? Eliminate tangled wires and the hassle of constant battery swaps—because nothing beats a device that runs autonomously. Hackaday’s community answered with a mix of polished designs and wild concepts, and the judges had a tough time picking favorites. Each of the three winners receives a $150 shopping spree at DigiKey. Let’s dive into the innovations that earned top honors.

Winner: LightInk Solar Watch

LightInk, created by [Daniel Ansorregui], is an e-ink wristwatch that pairs an attractive design with remarkable power efficiency. Its small wrist-mounted solar panel makes e-ink a natural choice for low-power displays. However, the true genius lies in the firmware: [Daniel] integrated the screen-updating routine into the wakeup stub within the RTC peripheral. This clever trick prevents the ESP32 from accessing SPI flash on every wakeup, saving precious milliseconds and slashing average power consumption by half. Even if you’re not after a stylish e-ink watch, this optimization technique is a valuable lesson for any low-power project.

Winner: Heliotrax Solar Supercapacitor Charger

Heliotrax, developed by [Nelectra], is a solar supercapacitor charger designed for IoT devices. It stores solar energy in low-maintenance supercapacitors and delivers a stable output voltage via a high-efficiency, low-leakage boost converter—overcoming the voltage variation typical of supercaps. Depending on the load, Heliotrax can charge in direct sunlight and keep a device running for several overcast days. This all-in-one module simplifies solar-powered IoT projects, making off-grid deployments easier to realize.

Winner: powerTimer Latching Switch Module

powerTimer, by [Juan Flores], is a simple latching electronic switch designed for ultra-low quiescent power. It sits between your microcontroller and power-hungry peripherals, cutting their leakage current when not needed. If you’d rather not wake the main MCU, powerTimer includes a low-power RTC for periodic wakeups. The judges appreciated its straightforward, practical approach to reducing system power draw without extensive redesign. It’s a perfect example of a small hack that solves a big problem.

Honorable Mentions

Solar-Powered Projects

Jake Wachlin’s Ultra Low Power Feather Development Board pairs a power-sipping microcontroller with low-power accelerometer and barometer sensors. It’s designed to operate in ambient room lighting—though direct sunlight or a strong lamp is needed for consistent operation. Meanwhile, Arnov Sharma’s SolMate is a handsome DIY solar power bank perfect for outdoor excursions.

Other Self-Powered Innovations

The competition also recognized projects harnessing other ambient energy sources. Although not detailed in the original announcement, these entries explored thermoelectric, piezoelectric, and electromagnetic harvesting methods—proving that the quest for sustainable power is far from one-dimensional.

Conclusion: The Future of Autonomous Gadgets

The 2026 Green Powered Challenge showcased that clever design and efficient energy harvesting can eliminate batteries and wires. From a watch that halfs its power draw through firmware optimization to a solar charger that handles voltage variations and a switch module that slashes leakage current, each winner offers a lesson in making devices truly self-sustaining. As these techniques become more accessible, expect to see a wave of autonomous gadgets that run on nothing but ambient energy—no batteries, no wires, just pure innovation.