[LeBleu]

$6,900 per panel adds up to about $3 million per lane-mile.

Typical rural highway costs for new highway are $3 - $9 million per lane-mile, with urban highways costing $5 - $20 million per lane-mile. (per http://www.railstotrails.org/resources/documents/whatwedo/po...)

The estimated 7.6 kwh per day per panel mentioned in the article, if you assume it gets that every day, adds up to 3.344 mwh per lane-mile, which at average US retail electric rates, adds up to $120,000 per lane-mile per year. According to their website, these panels will supposedly be designed to last 21 years, vs. the 7 typical for asphalt roadways. That would bring the lifetime electricity production per lane-mile up to $2.5 million. (not accounting for inflation nor electric price changes over 21 years)

Frankly, I find their 21 year projected life absurd, but then again I live in a state with yearly freeze-thaw cycles shortening the life of roadways. Other than that, it seems like if they could meet their claims, it would be financially feasible to build roads using this stuff.