VOA常速英语:抽水蓄能发电可减少碳排放

California promises to use 60 percent renewable energy sources for power generation by 2030 and all zero emission sources by 2045.At Castaic Lake, north of Los Angeles, a power plant with a double reservoir may help them do that. It’s one of 40 pumped storage facilities around the United States that is used for large-scale energy storage. A smaller site helps San Diego meet its power requirements and more are planned. The idea is simple. When you have excess energy during the day, you pump the water up a hill, and it stays there. At the end of the day, you’re able to bring that generating unit online and then supply the energy back to the grid. Producing power without burning fossil fuels, most utilities scale power is stored this way, using water. A smaller amount is stored with batteries, the kind used in electric vehicles and modern devices, in our cell phones, you know, laptop computers, but they are expensive.

So the challenge is to make them larger for transportation and power system application and make it cost-effective. He foresees a future when electric vehicles are tapped for power when not in use. Solutions where these vehicles energy could be delivered to the grid, we call it V2G. That’s vehicle to grid, but it’s a long way in the future. For now, water is used to store large amounts of energy, and Los Angeles power officials hope to build a major project at Lake Mead near Las Vegas where the Hoover Dam already generates hydroelectric power. If you could add some pumps and pipelines after it goes through the dam at some point downriver, pump it back upstream back into Lake Mead and just recirculate it, then you could actually increase the efficiency and optimize that asset, creating a pump storage component to the existing power plant, further reducing carbon emissions in the region.
Mike O Sullivan, VOA News, Los Angeles.