字幕列表 影片播放 列印英文字幕 We all live in a modern world—a world full of technologies that looked completely futuristic just a generation ago. Those modern, futuristic devices that help get us through the day all use energy, and to supply all of that energy, we need fuel. Today, the technology around generating clean renewable energy is evolving about as fast as the rest of our modern world. And among the most versatile examples is in fuel cell technology. Fuel cells provide critical energy backup for many large facilities, and they provide primary energy for some remote locations. Fuel cells are even being used to power vehicles and homes. How does it work? A fuel cell is sort of like a battery. It generates electricity from the simple and abundant hydrogen and oxygen found in chemical compounds all around us. And here's the cool thing: a hydrogen fuel cell's exhaust is nothing but water. There are several different types of fuel cell technologies. All are designed for specific applications, but essentially they all work on the same principles. Have a look at this. Hydrogen gas is fed into one side of the fuel cell, and air, which contains oxygen, is fed into the other. Hydrogen passes through the layers of the fuel cell, and as this happens, it induces a positive and a negative charge, which generates an electrical current. Finally, the hydrogen is combined with the oxygen and reacts to form H2O, better known as water. Individual fuel cells can be stacked to provide more power. The taller the stack, the more power it generates. Because of this stackability, fuel cells can be manufactured to scale for a variety of power needs. One important thing to keep in mind about hydrogen: it's not an energy source itself—hydrogen is what's called an energy carrier. That means energy from another source can be used to generate hydrogen. Hydrogen then stores the energy from that original source until it's used to power a fuel cell. One common way to extract hydrogen is through a process called splitting water, where hydrogen is separated from oxygen using an electrical current. Hydrogen can also be extracted from natural gas in a process called reforming. Although each of these methods requires some energy themselves, once extracted, hydrogen can generate electricity without any combustion—in other words, a clean energy source. One of the things that fuel cells are used for today is as backup power sources for industrial applications, like factories and universities. If the power grid should go down, then these fuel cells can be powered up to produce electricity with no harmful emissions. Today, hydrogen fuel cell test vehicles are already on the road. A local fueling station like this one contains hydrogen that then can be used by a fuel-cell-powered vehicle to run an electric motor. The result is an electric car with no emissions except water. In the future, we could see fuel cells powering even more homes, offices, industries, and vehicles, supplied by a reliable hydrogen infrastructure and supporting our nation's clean energy economy. Fuel cell technology: a long-term, sustainable solution to help meet the world's need for clean and reliable energy.