Powering the Future: A Scientist’s Guide to Energy Independence

4. Water power

Roll on, Columbia, roll on,Roll on, Columbia, roll on,Your power is turning our darkness to dawn.So roll on, Columbia, roll on.

—Woody Guthrie

Figure 4.1 Edwards Dam on the Kennebec River, at Augusta, ME, just before it was breached. (© AP Images)¹

Key facts

• Water power provides about 10% of the electricity in the United States, at least half of the electricity used in about one-third of the countries of the world, and more than 90% of the electricity in 24 countries, including Brazil and Norway. Large dams generate 19% of the world’s electricity.

• The U.S. has about 80,000 dams more than 6-feet tall, many built to provide ...