It's crazy. It'll never work. They cost too much. They'll crack. They're too delicate. You'll slide off them. Oil companies will never let it happen.

Scott Brusaw, an electrical engineer from Idaho, has heard it all before. Over the past eight years, skeptics (like this one) have been telling him his concept for solar roadways — replacing America's roads with solar panels, creating a power grid where pavement used to be — won't work. But Brusaw suddenly has a reason why it will — actually, 2.2 million of them.

Solar Roadways' crowdfunding campaign, which closed on Monday, raised $2.2 million — more than double what Brusaw was seeking — in just two months. The campaign, the most popular in Indiegogo's history, attracted more than 48,000 backers from all 50 states and 165 countries.

"It's been humbling," Brusaw, 56, told Yahoo News. "Really, really humbling."

The success can be attributed, in part, to a cheeky seven-minute video ("Solar FREAKIN' Roadways!") that has been viewed more than 16 million times on YouTube.

The campaign was also given a lift by celebrity Twitter endorsements from George Takei and Sean Lennon.

Brusaw, who launched Solar Roadways with his wife, Julie, says the funds will be used to open an office, hire staffers and test his prototype in Sandpoint, Idaho, which wants to be the first city to have them.

The concept has also received interest from an Amtrak station and the Sandpoint Airport, but they'll start with sidewalks and parking lots in town next spring, Brusaw says.

"At the end of this year, we'll have a finished product," Brusaw said. "It's not going to happen overnight — there's a learning curve here. Once we're convinced the final product works in a parking lot, we'll try residential roads. Then, eventually, the fast lane of a highway."

According to his calculations, the "smart" solar panels — encased in double-layered, bomb-resistant, bulletproof glass capable of withstanding 250,000 pounds — would, among other things, be able to generate "three times the electricity that we currently use in the United States," prevent accidents by melting snow and ice (and warning drivers of debris in the road with solar-powered LED lights) and even collect storm water. Oh, and cut greenhouse emissions by as much as 75 percent.

Brusaw, a former Marine Corps weapons technician, says he and his wife came up with the idea after watching Al Gore's film "Inconvenient Truth."

Yet despite the obvious environmental benefits, Brusaw says the idea initially received little interest from investors.

"Everybody was interested, but no one was willing to give us research money," he said.

It wasn't until he starting pitching the concept as intelligent infrastructure and a smart grid that it caught fire.

In 2009, Brusaw got $750,000 from the Federal Highway Administration to develop the prototype. "They're interested in infrastructure, and that's what we make," he said.

Grand ideas aside, Brusaw remains realistic.

"Ten years from now, I hope we have a whole lot of parking lots and a whole lot of driveways," he said. "And the fast lane of a highway."