[ASSURAS] Come fly a kite with us. This is "energyNOW!"

Hello, I'm Thalia Assuras. Welcome to "energyNOW!", a weekly look at America's energy challenges and what we're doing about them. Today, we're going to focus on the complex challenges facing wind energy. Sure, it's an abundant, renewable source of power, but it only works when the wind blows, making it less reliable than nuclear- and fossil-fueled power plants. Even so, America's use of wind power is growing and it's one of the oldest energy sources we have.

[NARRATOR, DEPARTMENT OF ENERGY FILM] The idea of windmills was brought here by early European settlers and used in many ways.

[ASSURAS] Wind energy has come a long way since then. It's now a multi-billion-dollar industry, employing more than 75,000 people in 42 states. Even so, wind supplied only about 2% of the nation's electricity last year. But its supporters see wind playing a much larger role.

[BARACK OBAMA, APRIL 27, 2010] Wind power isn't a silver bullet, it's not going to solve all our energy challenges. The key is to understand that this is a key component, a key part of a comprehensive strategy.

[ASSURAS] This year, Iowa is getting 18% of its electricity from wind, more than any other state. And the Department of Energy says by 2030, wind has the potential to produce 20% of our electricity nationwide.

[ANNOUNCER, VESTAS COMMERCIAL] We will not rest until wind is on a par with oil and gas.

[ASSURAS] But to get there, wind farms like this aren't enough. About one in five new turbines would need to be offshore, where the wind is faster and more consistent. That's already happening in Europe. But here? Still on the drawing board.

[MAN] We need wind power -- not there!

[ASSURAS] Take Cape Wind, a controversial project off Cape Cod, Massachusetts, that took nine years for federal permits, hit another snag in October, after an appeals court ruled the federal government failed to properly study how the turbines will impact aircraft.

But there are other offshore wind projects taking shape off the coasts of Rhode Island, Delaware, and New Jersey. Offshore or on, all new wind projects could be in jeopardy if federal production tax credits expire as scheduled at the end of 2012. The Energy Information Administration says those tax credits and other federal wind subsidies totaled almost $5 billion in 2010. But the wind industry says renewable energy sources are still getting less than 10% of the support received by oil, natural gas, and nuclear in their initial stages.

Besides the money, another big challenge for wind energy -- if there's no wind blowing, there's no energy created. Turbines send electricity to the grid about half as often as the average coal plant, and even when the wind blows, if the electricity isn't used right away, it's lost. Too difficult to store.

But now there's something that could enhance the reliability and viability of wind -- battery storage. And you can find it in the heart of coal country -- West Virginia. More from Patty Kim in this "energyNOW!" Spotlight.

[REPORTER, 1969] We have a liftoff.

[KIM] We've put a man on the Moon...

[ARMSTRONG] One giant leap for mankind.

[KIM] ...built planes that fly faster than the speed of sound... and created the Worldwide Web. But we haven't come up with an efficient way to store electricity on a large scale, until now.

This is one of the largest energy storage systems of its kind in the entire world. Now, it's pretty unique, but it may not be for long.

[PRAVEEN KATHPAL, AES] Projects like these are the beginning of a long wave of energy-storage projects to come.

[KIM] This is the beginning of something big. And is that exciting to you, personally?

[KATHPAL] Very personally exciting for me.

[KIM] Praveen Kathpal is with AES, the firm behind this storage system and this new wind farm in West Virginia, Laurel Mountain. The farm generates enough power to run well over 20,000 homes. Spanning over a dozen miles are more than 60 turbines. These wind turbines -- which are about as tall as the U.S. Capitol building, if you can believe it -- feed energy into one of the largest power markets in the world, stretching across the American northeast and midwest -- that's about 50 million people.

And the key to keeping their lights on with cleaner, more reliable electricity may lie inside these shipping containers.

Wow! It's like we're going inside a bank vault.

[KATHPAL] Yeah, come on in.

[KIM] Check this out.

Here, you'll find over a million lithium ion batteries.

[KATHPAL] They're about the size of a C or a D cell.

[KIM] Really?

The batteries do something called "frequency regulation," making sure that, at any given time, supply and demand on the grid are perfectly matched so things run smoothly and blackouts don't happen.

So these guys are really the army, if you will, on the front lines.

[KATHPAL] Exactly.

[KIM] Batteries get their marching orders from the power grid operator every four seconds. A signal tells them either to send electricity to the grid or store any excess for later use, when the wind isn't blowing.

[KATHPAL] It's a level of control over power that we haven't seen.

[KIM] When it comes to power, some say we've been doing things the hard way.

[KATHPAL] It just shoots on to the wires and it has to be produced and consumed in real time. When you go to Whole Foods, and everyone else is there at 7:00 in the evening doing their grocery run, and everyone is demanding milk, right now, it's as if people have to be out there milking cows in real time to provide that amount of milk.

[KIM] So you really control the world right here at your fingertips.

[KATHPAL] Just a few batteries in the world, not the whole world.

[KIM] Okay, so world domination, it isn't. At least, not yet. The goal is to build even larger storage systems, ones that could hold oodles of clean energy and supply a steady stream of power at peak times, when electricity demand and prices are the highest.

[KATHPAL] The power plants we're using at peak are the most expensive and inefficient cows you could be milking.

[KIM] With a bigger battery backup, having more clean energy that's more reliable than ever could be a breeze.

[KIM] In Elkins, West Virginia, Patty Kim, "energyNOW!"

[ASSURAS] The battery you just saw is designed to store and release fairly small amounts of electricity to help keep the grid stable. But in theory, it holds enough electricity in a single charge to power roughly 5,000 homes for 15 minutes. AES now wants to build a larger battery project, about three times bigger, for a utility company in west Texas.