In the past, solar was exclusive to satellites and swimming pools. No longer. Today, America has become a growing market for rooftop solar cells, and 100,000 Americans are employed in the sector. Every time the deployment of solar photovoltaic cells doubles worldwide, the price drops by 18 percent. Solar is expected to become cost-competitive with grid electricity in many regions of the country over the next 5 years.
The Earth produces more internal energy, in the form of heat, than humans can possibly use. Like solar, the use of geothermal energy is only limited by technology and the associated costs. The United States has the most installed capacity of geothermal energy in the world, about 3,102 megawatts across nine states. Thanks to investments from the Recovery Act, there are nearly 200 more projects, totaling more than 5,000 megawatts, in development across the United States.
Biomass power generators use plant and other organic matter to produce electricity. Biomass available for electricity generation includes residues from forests, mills, and agriculture, as well as dedicated energy crops and urban wood wastes. One example of a state using its biomass resources for electricity is Maine, where biomass generates a quarter of the state's electricity. Biomass can be used as the sole fuel source for power plants, or it can be used in conventional power plants to substitute for a portion of the traditional fuel, typically coal, in a process called co-firing.
Federal land ownership began when the original 13 states ceded land they controlled between the Appalachian Mountains and the Mississippi River to the federal government in the late 18th century. The Federal government acquired lands further west, beginning with the Louisiana Purchase and culminating in the purchase of Alaska in 1867. Today, the American people own approximately 653 million acres, or about one third of the acreage in the United States, predominantly located in 11 western states.
Beginning with establishment of the world’s first national park, Yellowstone, in 1872, the National Park System has grown to include nearly 400 units covering roughly 84 million acres. The System includes over 20 different kinds of units, including national parks, historic sites, monuments, rivers, trails and battlefields. The largest unit is Wrangell-St. Elias National Park and Preserve in Alaska, covering more than 13.2 million acres; the smallest unit is Thaddeus Kosciuszko National Memorial in Pennsylvania at .02 acres. More than 275 million people visit the National Park System each year.
The United States holds approximately 55 million acres of land in trust for tribes and individual Indians across the United States, ranging in size from 16 million acres on the Navajo Nation Reservation in Arizona, New Mexico, and Utah to the 1.32 acre Pit River Tribe parcel in California. Native Lands represent 5% of the U.S. land base and are rich in renewable energy resources including solar, wind, geothermal, hydroelectric and biomass, as well as other energy resources including coal and natural gas. There are approximately 4.5 million Native Americans in the United States, many of whom reside on their tribal territories.