[Dr. Scott W. Tinker] Here's the short story on biofuels. We've been making them for more than a century, but they're still not quite there yet. Biofuels are basically sugar, fermented into alcohol. And on a much smaller scale, plant oil, or even algae turned into diesel. Brazil has been the most successful with biofuels making ethanol that's cheaper than gasoline. But everywhere else it's still more expensive. And mostly they're made from food crops, grown on farm land with lots of water, fertilizer and energy required. Many challenges. But there's a new biofuel process that breaks down the cellulose of the plant, it's woody structure into sugars that can be fermented. This means that the whole plant, any plant, grown anywhere can be used. The most promising have been perennial grasses that can be planted once, then harvested for many years. It can grow on land that may not be suitable for food crops with less water and fertilizer. In colder climates, fast growing shrubs and trees are well-suited, and the ability to use lumber and food waste make this technology very promising. But so far, cellulosic fuel is experimental. It's been hard to scale up into pilot plants like this one. And there are no commercial plants anywhere in the world. This is largely because cellulosic ethanol is currently three times as costly as Brazil's sugarcane ethanol. Some predict that in a few decades, it could be the cheapest liquid fuel anywhere. If so, the sheer acreage required to fuel global transportation would be the limiting factor. So that's what you need to know about biofuels. They're a regional supplement that may play an expanding role, depending on technology, cost, and ultimately, land use. You can see more on cellulosic biofuels in other parts of this project.