Cheap, powerful, and available almost everywhere—solar energy is a truly great thing. With these 10 sun-powered projects, you can turn a sunny day off into some brag-worthy, possibly money-saving backyard tech.


Photo by david.nikonvscanon.


Leave them alone long enough, and nearly every kid will investigate, or at least hear about, the devastating effects of magnifying glasses and clear, sunny weather on insects. Route that fascination with concentrated sunlight into some wood engraving. Aluminum foil (or, preferably, foil tape), sunglasses, a razor blade, and a magnifying glass are all you need to get creative with an old piece of wood or other dark objects. You'll need to provide supervision, lest bad aim turn into a kindling incident, but it's a great project for kids, as well as a unique way to leave your mark with style. (Original post)



Engrave wood with a sun laser The always creative Instructables has come up with a way to engrave stuff onto wood using only… Read more


It's not an efficient way to keep your hot tub filled, but the kind of solar-powered water heater detailed at the Instructables link above can get a big batch of water up to 170F without requiring any work from your water heater, and the kit costs around $5 with the right parts suppliers. Even if you pay a bit more, think about how often the backyard grill, deck, or pool could use a little cleaning with some hot, soapy water. This project gets you a free source of ever-ready cleaning water, and at a pretty neat price. (Original post)




This little project is the most reliant on a strong bit of sunlight, but totally worth the effort when you pull it off. The chocolate polishes the bottom of a soda can, which better focuses and intensifies sunlight reflections, creating a cone of fire-starting power that leaves your fellow campers impressed—or the other attendees at the park picnic grateful you were there when they forgot the matches. (Original post)





If you've got a small-ish lawn, a battery-powered mower is much easier on your and your neighbors' ears, and it saves you the hassle and cost of gas refills. Take those eco-benefits to the next level by converting a gas-guzzling push mower to use a solar-charged battery. Appropedia's version is a definite weekend project for an older model, but if you've got a newer battery mower, it's not too hard to simply start charging it with a solar panel instead of your wall socket, and this guide will help get you there. (Original post)




A solar-powered house sounds like a neat idea in abstract, but how would you know if your house's roof could really sustain worthwhile energy? Luckily, a big search company has overhead images of just about every house out there, and mashup tool RoofRay can use that image, plus your location's average sunlight and some roof details, to get a starting estimate on whether you can use the sun to push back on your power meter a bit. (Original post)





Probably the least practical and most expensive of the projects listed here, the solar-powered Wi-Fi extender is definitely the most rewarding from a geek cred and green power perspective. Popular Science explains in great detail how to solder and network together a semi-standard Linksys Wi-Fi router, range extender, solar panel, battery, and higher-powered antenna, and then set it up to grab Wi-Fi from your household's main network and expand it to the great outdoors—or, at least, the outdoors behind your house. That leaves you with regular web access anywhere around your property, without having to worry about running cables across the lawn. (Original post)





There's an entire realm of recipes and cookbooks that purport to help you get cooking done in the summer without turning on your oven. Skip the gazpacho and the house-warming heat with an oven built from aluminum foil, construction paper, plastic, and a few other household items, including a firm cardboard box. It's great for saving energy, saving time, and feeling like you really made the most of a warm, sunny day. Want to get a bit more efficient and physics-y with your outdoor oven? Try a parabolic solar cooker. Photo by thescarletmanuka. (Original post)



DIY Cardboard Box Solar Oven Eco-friendly weblog The Daily Green details how to turn a cardboard box into a DIY solar oven for a Read more



If you're lucky enough to live where plants and food grow all year, you already know the power of photosynthesis. For those who could use a little more prep time for their seedlings, a longer growing season, or just a buffer against the occasional plant-punching dry spell, The Door Garden explains how to take some light construction materials—$50 if you happen to have most of it lying around, about $150 purchased new—and build a greenhouse that will withstand most winters and thrive in every other season. Just got a few plants you want to get started with condensed solar power? Try the mini-greenhouse made from a window. (Original post)





We're big fans of the MintyBoost DIY USB charger kit, a great project for electronic beginners and pros alike. It was only a matter of time, then, until someone switched the power source from AA batteries in an Altoids case to a lithium-ion battery with solar charging capabilities. Completing the modified kit isn't a great leap more difficult than the original, and once you do, you'll be glad to get a lot more use out of your windowsills, and hand over a lot less money at the grocery store every few weeks. It's not necessarily the most effective method of charging, but it's undeniably cool. (Original post)



DIY battery-powered USB charger Instructables has a step-by-step for building your very own Altoids tin USB charger (dubbed the… Read more



The solar-powered outdoor lights they sell at your local garden/home improvement store can be subtle or original-looking—if you want to pay a premium. Otherwise, you're stuck with painted plastic and models that hold a pretty weak charge. The sun jars constructed by our own Jason, on the other hand, cost only about $11 each—less if you have jars or batteries on hand—and give off a pretty neat glow, powered entirely by solar energy from earlier that day.

What sun-powered projects are in your mental queue for some sunny weekend? What great solar hacks have you pulled off already? Tell us all about them in the comments.