As interest increases in alternative energy, wind power has emerged as one of the best alternatives to fossil fuels. Which is why wind farms are popping up throughout the United States and around the world.

But you can't just set up a wind farm anywhere and expect it to produce enough power. Why? Because some places are windier than others.

What Causes Wind?

Wind happens because when sunlight hits the earth, it warms some spots more than others, creating warmer and cooler areas that fluctuate throughout the year. Because warm air weighs less than cold air, it rises, leaving in its wake an area of low air pressure. Then cooler, higher pressure air whooshes in to replace the warm air.

And that's what we call wind.

Where Is It Windier?

The closer high and low air pressure areas are to one another, the more wind there is. That's why, for example, coastal areas tend to be very windy. During the day, land heats up more quickly than the sea. So when air over land rises, cooler air over the water blows in to fill the gap.

That's why many wind farms are on the coast. The tops of rounded hills, open plains, and gaps in mountains are also good spots.

Wind power isn't a perfect solution, of course. Because even in the windiest places, the wind doesn't always blow. But as long as wind farms are built in places where winds often blow strongly, wind could be an important part of the energy mix.

Read More: Wind Power (darvill)