Nobody likes power cords, and batteries always need recharging or replacing. What if your device could run on only the power it could gather together by itself from the world around it? It would be almost like free energy, although without breaking the laws of physics.
Hackaday’s 2026 Green-Powered Challenge asks you to show us your devices, contraptions, and hacks that can run on the power they can harvest. Whether it’s heat, light, vibration, or any other source of energy that your device gathers to keep running, we’d like to see it.
The top three entries will receive $150 shopping sprees courtesy of the contest’s sponsor, DigiKey, so get your entry in before April 24, 2026, to be eligible to win.
Honorable Mentions
As always, we have several honorable mention categories to get your creative juices flowing:
- Solar: In terms of self-powered anything, photovoltaic cells are probably the easiest way to go, but yet good light-harvesting designs aren’t exactly trivial either. Let’s see what you can run on just the sun. (Or even room lighting?)
- Anything But PV: Harnessing the light is too easy for you, then? How about piezo-electric power or a heat generator? Show us your best self-powering projects that work even when it’s dark out.
- Least Power: Maybe the smartest way to make your project run forever is to just cut down on the juice. If your project can run on its own primarily because of clever energy savings, it’s eligible for this mention.
- Most Power: How much of a challenge is building a solar-powered desk calculator in 2026? How about pushing it to the other extreme? Let’s see how much power you can consume while still running without batteries or cords. Does your off-grid shack count here? Let’s see it!
Prior Art
We’ve seen a lot of green-powered projects on Hackaday over the years, ranging from a solar-powered web server to a microcontroller powered by a BPW34 photodiode. Will your entry run off the juice harvested by an LED? It’s not inconceivable!
Solar cells only work when the sun shines, though. As long as your body is putting out heat, this Seebeck-effect ring will keep on running. (Matrix vibes notwithstanding!) Or maybe you want to go straight from heat to motion with a Stirling engine. And our favorite environmental-energy-harvester of all has to be the Beverly Clock and its relatives, running on the daily heat cycles and atmospheric pressure changes.
Your Turn
So what’s your energy-harvesting project? Batteries are too easy. Take it to the next level! All you have to do to enter is put your project up on Hackaday.io, pull down the “Submit Project to…” widget on the right, and you’re in. It’s that easy, and we can’t wait to see what you are all up to.
And of course, stay tuned to Hackaday, as we pick from our favorites along the way.
The graphic got me hoping this was going to be a gardening/agriculture challenge.
That would have been nice, actually green. I run my family on organic food grown in my own garden from the power of the sun and that food powers the most powerful computational engines ever known, the well educated human brain.
Oooh. Noted.
Excited for the next one then!
Although this is a great time for a growing project since it’s planting season.
I can see how all those companies doing vertical farming in Philly power local economy quite well. I am quite sure lettuce or tomatoes are not their most profitable plants they grow, just the side gig to make it look different.
(as a side note, any farming sooner or later pivots into breeding local varieties that would be best suited to the environment; I’ve yet to hear of, say, Philly-branded strawberries or Philly-branded onions; actually local vertical farming industry seem to be mostly geared towards bestest/fastest ROI and flipping the investment opportunities, and not towards introducing best varieties of plants grown, which seem to be their tertiary/auxiliary priority; though, I’ll give them credit for growing awesome flowers for the annual Philly Flower Show, which seem to deliver at least something else in addition to w**d).
Are there any rules on professionalism? If I came up with something funny could it still win?
For or against professionalism? This is Hackaday. I think you get extra points for funny.
Awesome. I have an idea
Based on these rules, I could enter 50% of the homes in my state. They run quite a lot on solar :D