英语听力：自然百科 智能电网（上）（在线收听）

The United States has started the largest infrastructure project in human history, a complete top-to-bottom overhaul of our entire electrical supply grid, retrofitting new intelligent devices at every step from the power company's generators to the devices in our homes and making sure every component is secure from attack, while also adding in control of water, gas and sewage systems. And this total makeover must happen while the whole system is operating online at peak capacity, while it's growing in fact. In short, we've begun building a smarter power grid, one that works pretty much like the internet. You could call it, the InterGrid.

Our aging power grid system is starting to fail. We've seen more blackouts and brownouts, and it runs inefficiently, wasting carbon into the air. New clean sources like wind and solar which make power only part of the time need intelligent pathways to get to consumers, and the Americans prefer the power they use to have been produced by Americans. Right now, our fragile, less-than-smart power grid, interconnect nearly 10,000 utility plants, that's well over a million megawatts of generating capacity, about half of it comes from burning coal. At least one third of the United States’ carbon output, maybe more, comes from power generation. Almost one fifth of our power steams onto the grid from the boiling water, heated by the nation's 104 nuclear reactors. Nearly six percent of the electricity used in the US comes from flowing or falling water, hydroelectric power generated at river dams.

But the same six percent of all the electric power that's produced gets lost before it gets where it's supposed to go. It either melts away as heat as it travels long more than a quarter million miles of metallic wire, or it simply

shots the grid, undetected somewhere within the constant maintenance headache of the decaying patchwork of cable towers and poles.

Reclaiming just that six percent would be the equivalent of taking 55 million cars off the world in terms of the petroleum saved and greenhouse gases prevented. For the past quarter century, the peak demand for power has been outpacing investment in new transmission lines and power regulation systems that can only react when something goes wrong.

They are not good at spotting problems before they happen. The old grid flies perilously close to the breaking point, every hot day in sunlight cities.

According the Department of Energy, US businesses lose over a hundred billion dollars a year to blackouts and brownouts. The power that does arrive has to be used as soon as it gets there. But up until now, there hasn't been a good way for consumers to tell the power company how much power they might want to purchase. To keep our electric grid from grinding to a halt, the new InterGrid will work on a principle known as 'prices to devices'.

If you knew that electric grids were going to spike very high this afternoon, you might decide to leave your home air conditioner off while you are out ofthe house. Well, suppose your air conditioner, in fact your entire home, knew it before you. What if those devices, your thermostats, washers, driers, refrigerators, Jacuzzis could make decisions about how much energy to purchase according to your preset preference and telling the utility company what you are willing to pay. And that's truly speaking truth to power.