Could solar panels eventually replace asphalt and concrete?

Courtesy of Dan Walden

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As the world focuses on renewable energy, scientists are looking more and more to a source of power than has kept mankind warm and alive for as long as we've been around: our sun.

These days, we can find solar panels -- also known as photovoltaic cells -- just about everywhere. They're on the roofs of our homes, bringing down the cost of electricity. The all-new 2010 Toyota Prius hybrid even has them on its roof, powering an electric air conditioner to keep the interior cool so the gasoline-powered engine doesn't have to work so hard [source: Carney].

The applications for solar panels are growing exponentially. Photovoltaic cells work by using semiconductors to absorb light and create a flow of electrons, which can power any number of electrical devices. Just as one simple example, it's probably safe to assume that most everyone has used a solar-powered calculator at one point or another.

Some have even theorized that if we were to lay down a gigantic amount of solar panels over a wide area, we could absorb enough sunlight to power entire cities, effectively ending our energy crisis. The problem is, there's nowhere to put them -- we can't exactly stick panels across the entire countryside.

Or can we? We have a network of roads all over the country, and now we even have cars being manufactured with solar panels on them. Put the two together and you get a unique solution: solar panels on our highways.

This could mean that the panels could be placed along our roadways as sound barriers, or an even more extreme idea -- that the roads themselves will be made of solar panels.

In this article, we'll examine the pros, cons and feasibility of these ideas and see if solar cells could be the asphalt of the 21st century.