Somewhere on the list of the most successful crowdfunding campaigns—wedged between video games, smart watches, and cult movies—you’ll find a project that could change more than just how we spend our leisure time. Last month, the Idaho-based startup Solar Roadways ended its Indiegogo run with $2.2 million in pledges. The only thing more impressive than the money is the idea itself: turn roads into solar panels. Here’s what you need to know about the project—and three more solar technologies like it—that could change the world.

Solar Roadways

The pitch: Replace roads, sidewalks, bike paths, parking lots, and recreational surfaces with smart, sustainable solar panels.

The details: Solar Roadways are composed of three-layered panels with a translucent sheet that provides traction on top of electronics and base layers. The project would generate clean electricity, replace telephone poles with underground passages, and through heated surfaces could keep roads clear of snow. Additionally, production and installation would create thousands of green jobs, and the value of the power created would pay for the roads over time.

The catch: Critics have raised several issues, but the project’s most apparent obstacles are its colossal scope, cost, and timeframe (especially when you consider how long it takes just to get that pothole on your street fixed).

Solar Paint

The pitch: Turn paint into solar panels to allow any exposed wall to generate electricity.

The details: While the materials typically used in solar panels make them flat and awkward, a new approach—using cheap, metal nanoparticles instead of silicon—could solve that problem. Canadian scientists at the University of Alberta are developing spray-on paints that can coat sheets of plastic, converting them into solar cells. A similar process can also turn windows into panels.

The catch: While these “organic” materials are cheaper than traditional solar cells, they’re also much less efficient.

SEE ALSO: The World’s First Country To Get Solar Panel Bike Lanes Is Exactly Who You’d Expect…

“Origami” Solar Panels

The pitch: Use origami-inspired shapes and bends to maximize surface space and minimize weight.

The details: Engineers at Utah’s Brigham Young University are repurposing the principles of the ancient art of origami to maximize the efficiency of outer-space solar arrays. When launched, the arrays are compact and lightweight; when in space, they fold out to ten times their original size to capture the most sunlight possible. The team has also suggested the idea could be used for portable emergency shelters here on earth.

The catch: As the idea is still in its infancy, researchers have only used small-scale models to test the idea so far.

 

Solar Balloons

The pitch: Use sunlight, rather than gas canisters, to lift a hot-air balloon.

The details: The solar balloon—a dark-material aerostat that uses solar radiation to stay afloat—is not a new, or particularly complicated, idea. With roots back to the ’70s, both manned and unmanned solar balloons have been flown successfully on earth and are now primarily considered toys. But two California projects are showing that solar balloons are not merely playthings: They can be used to generate electricity and survey planets like Mars.

The catch: No major issues, though the idea has yet to capture widespread support or attention.