Chief Joseph Dam in Washington state is the second-largest hydropower producing dam in the United States.
On Christmas Eve 1968, the astronauts of Apollo 8 took a photo from space that changed the way the world saw itself. It was the first-ever photo of Earth, revealing “a glowing marble of blue oceans, and green forests, and brown mountains brushed with white clouds.” President Obama recently invoked that event in a June speech announcing his new Climate Action Plan, which calls for the U.S. to dramatically increase its use of renewable energies. “Over the past four years, we’ve doubled the electricity that we generate from zero-carbon wind and solar power,” the president said. “So the plan I’m announcing today will help us double again our energy from wind and sun.” What the president didn’t mention in his speech was America’s—and the world’s, for that matter—largest renewable energy source: water. That marble of blue that dominates the view of Earth from space and accounts for more than 60 percent of all renewable power in the U.S. rarely, it seems, gets the same billing as wind and solar. For a power source that is clean and renewable—it doesn’t pollute the air because no fuels are burned and it’s renewable because it uses the Earth’s water cycle to generate electricity—one would think hydropower would get as much attention and investment as other noncarbon sources of energy. But in general, hydropower is not even considered a renewable energy in most states or, for the most part, by the federal government. So it begs the question, is hydropower a renewable energy or not? The answer to that is key since it underlies policies states develop in fulfilling ambitious renewable energy goals. Read the rest of this month's magazine issue. Hydropower is more than 100 years old in the U.S. The first dam to use hydraulic reaction turbines to generate electricity here was in 1882 on the Fox River in Appleton, Wis. It was revolutionary at the time and the results were so impressive that it kicked off a dam-building spree: From 1905 through the 1930s, several large, iconic dams, including the famous Hoover and Roosevelt dams in the West, were constructed. During that time, nearly 40 percent of the nation’s electricity came from hydropower. By mid-century, the growth of hydroelectric power through dams was on the wane as other forms of power generation—nuclear, natural gas, coal—gained momentum. Today, hydropower makes up only about 6 percent of the U.S. electric supply, with the largest hydropower producers in the West: Washington, California and Oregon. Outside the U.S., hydropower accounts for 16 percent of global electricity production. There are several types of hydroelectric facilities, but all are powered by the kinetic energy of flowing water as it moves downstream. Turbines and generators capture and convert that energy into electricity, which is then fed into the electrical grid. The water itself is not reduced or used up in the process, and because it is an endless, constantly recharging system, hydropower is defined as a renewable energy by the Environmental Protection Agency. But it’s not considered renewable by everyone. It comes with some “pretty significant environmental baggage,” says John Seebach, senior director of federal river management with the conservation group American Rivers. “The reluctance to call hydropower a renewable energy is based on the impact of dams on fisheries and water flows.” Several large dams block migrating fish from reaching their spawning grounds. Dam reservoirs impact flows, temperatures and silt loads of rivers and streams. Over the years, these factors have drastically reduced fish populations. At one time, the Klamath River in Oregon and California had salmon runs in the millions. The construction of four dams along the river reduced the fish runs to a fraction of that. That’s why hydropower doesn’t count toward utilities’ renewable energy mandates in most states—that, and the fact that there is already so much hydro out there. More than 30 states have renewable portfolio standards (RPS) that require utilities to generate a percentage of their power from renewable sources. Counting all hydropower would significantly lessen the impact of these standards, particularly in states where hydropower already provides a substantial amount of electricity. In those states, experts say, counting it would discourage the development of new renewable sources. Similarly, if hydropower were classified as renewable, some states would have to reset their targets and those might end up unrealistically high. Want more energy & environmental news? Click here.
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