The Idaho couple who created an innovative road surface made of solar panels is back with a prototype, and they're looking to Indiegogo for additional funding.

Scott and Julie Brusaw want to replace traditional asphalt and concrete with impact-resistant solar panels that do double duty as a road surface and an energy source. When the solar roadway concept debuted in 2010, it caught the interest of futurists and government officials. Now the Brusaws have a working prototype covering a 12- by 36-foot parking lot outside the couple's electronics lab in Idaho.

The new panels look quite different from the prototype we saw almost four years ago. The latest design is hexagonal, which allows for better coverage on curves and hills. They're also heated for easier snow and ice removal, and include LEDs that can display road markings or even messages.

According to the Brusaws, the new glass-covered panels have been tested for traction and impact resistance, and can sustain a 250,000-pound load. They've even got a – video of a tractor driving over the parking lot prototype. This is also the first time the panels have been subjected to real-world road conditions, and the parking lot includes a dedicated channel for drainage and utilities.

Up until this point, the project has been financed through a $50,000 private grant and two phases of funding from the Federal Highway Administration. Now, the Brusaws have launched an Indiegogo campaign to raise $1 million for commercialization of their prototypes.

It's an interesting concept. Individually, small solar parking lots and crosswalks can power signs and street lamps. Deployed across a whole town, a network of solar roads could act as a decentralized electric grid, sending power to homes and businesses.

There's no word yet on how much the prototype installation cost—those numbers are being worked up and should be ready in July—but the Brusaws say a commercialized solar roadway will provide enough power to pay for itself over its lifespan.