字幕列表 影片播放 列印英文字幕 We all need fuel to get around. And as America takes steps to improve our energy security, homegrown fuel sources are more important than ever. The Energy Department is researching one of the fuel sources of the future found here: in algae. Have a look at this algae farm. These large, man-made ponds are called raceways, and they cultivate a new crop of algae every few weeks. You see, algae, or more correctly, microalgae, are very small aquatic organisms that convert sunlight into energy. Some of these algae store energy in the form of natural oils. Under the right conditions, algae can make a lot of oil that can be converted into biofuels. Algae could potentially produce up to 60 times more oil per acre than land-based plants. Extract that oil, and you have the raw materials to make fuel for cars, trucks, trains, and planes. In the future, anything that runs on gasoline and diesel could also use biofuel from algae. The oil is extracted by breaking down the cell structure of the algae. This can be done by using solvents, or sound waves. After the oil is extracted, then it is further processed at an integrated biorefinery or, in the future, at a traditional oil refinery. Another great benefit of algae? Consider this: like plants, algae needs carbon dioxide to grow and that's good for the environment, since it takes CO2 out of the atmosphere, making it a nearly carbon-neutral fuel source. There may even be opportunities to build algae farms next to power plants that use fossil fuels actually using CO2 exhaust to feed algae ponds. There are over 100,000 different strains of algae. Some grow better in different climates, or in freshwater, saltwater, or even wastewater. So, scientists are testing different algae under many different conditions to find the best strains and develop the most efficient farming practices. While commercial production is still a ways off, algae holds great promise to become a reliable, homegrown fuel source to reduce our nation's reliance on foreign oil.