[Dr. Scott W. Tinker] So here's what you need to know about wind. It's the fastest growing renewal. Why? First, it's simple. Wind turns the blades, which turns the generator, and that makes electricity. Then, it's modular. You can put up a few wind turbines to help power a village or put up a lot and you've got a wind farm. And you can do it fast. A wind farm can be built in a few years, and in the world of energy that's very fast. Then, wind is available. Most countries have usable wind. And some of the biggest power consumers, like the U.S. and China, have a lot of it. But wind's most important benefit is that it's affordable. Wind power is about the same price as natural gas power, and that means people will build it. And of course, once it's built, there are zero emissions, carbon or anything else. That's a pretty good deal. But wind has a few downsides. Some people don't want to look at all the turbines, and the closer they are the less people want to look at them. So you can put them offshore, but this makes wind power several times as expensive. Or you can put them far away, like in the great plains, but then you've got to build long distance transmission, and it turns out that's much more of a challenge than building the wind farm itself. Wind has environmental impacts. It kills birds and bats, requires mining for metals, and disposal once the blades wear out. Finally, the biggest challenge is that wind is intermittent. It only makes power when the wind is blowing. So it may not be there when we need it most like on a hot summer day when everyone is running their air conditioner. That means we have to back up wind with another fast starting power source, ready to jump in when the wind dies. That's usually natural gas. So wind is a new clean power source that is affordable unless building transmission and backup generation make it unaffordable. Which goes to show that every energy source is a trade off of pros and cons and that a successful energy transition will require the right balance of many energy sources. In the film we discover what that mix is.