Energy today and in the future is likely to come from numerous sources. Efforts to develop those sources are under way in Indian Country and on private land, and hundreds of thousands of jobs are likely to be created over the next decade by the development. Here is a brief look at some sources under development:

Solar

Solar power is delivered in three primary ways – small solar-thermal units for hot water, rooftop photovoltaic units and large power plants that generate electricity.

Solar development faces challenges. Because the sun sets at night and can be intermittent during the day, better systems for storing and delivering captured energy are needed. Production costs also are higher than for efficient coal plants.

Biofuel/Biomass

These energies are produced from living organisms or organic and food-waste products.

Algae and bacteria are among the many newly emerging biofuel sources because they do not require large land areas and provide constant and intense energy supply. Forest, lumber, paper mill, crop, landfill and sewage wastes can be used for biomass and biofuel energies, providing electricity and transportation fuels while reducing environmental burdens.

Among the promising development projects around the country are efforts by Solix Biofuels, in which the Southern Ute Indian Tribe is a key investor and owner. Also promising in the field is the development of Helioculture, which is a process that has the possibility of producing a hydrocarbon-based fuel using brackish water, nutrients, photosynthetic organisms, carbon dioxide and sunlight. The process could produce 20,000 gallons of fuel per acre. And turning trash to gas, or energy treasure, has become part of this renewable-energy category, Countless efforts are under way to sequester gas emitted by decomposing trash in America’s landfills. About 90 percent of America’s purchases reportedly land in a landfill within six months.

Wind

Wind power is the most developed of the renewable-energy sources. It has been used in its current form for more than two decades.

Wind energy is an intermittent source, so energy-storage technologies or supplements are necessary.

Further development could create more than 50,000 jobs nationwide, particularly for trade workers and displaced manufacturing workers. Wind power is expected to grow to more than 6 percent of the nation’s energy mix by 2030.

The cost of wind-power production is higher than that of efficient coal plants, but turbines in recent years have become more compact and efficient. Further efficiency also could be reaped with offshore wind farms, because larger turbines that produce more energy can be used.

Geothermal

Geothermal energy generates a reliable and constant supply of electricity from high-grade underground hydrothermal resources in seven Western states. The United States is the global leader in geothermal generating capacity.

Energy production costs for new geothermal plants are comparable to existing hydro, nuclear and coal plants. And the power source is constant.

Geothermal energy production is expected to grow significantly in the next 50 years but is likely to account for less than 5 percent of the nation’s energy mix in the long run.

Coal

Coal is the most abundant domestic fossil fuel worldwide and more than 1 billion tons are produced annually in the United States. More than half of the nation’s energy comes from coal and 90 percent of the mined resources stay in this country.

Coal is one of the cheapest forms of energy and is the largest source of electricity in the country but has drawn critics because of negative impacts its extraction and use can have on the environment.

Coal mining employs about 130,000 people with an estimated three additional jobs created elsewhere in the economy for every direct mining job.

There are about 600 coal-fired power plants and 1,100 coal-fired manufacturing plants in the nation.

Natural Gas

Natural gas development in the United States has the potential to become a leading energy option as new technologies continue to allow extraction from unconventional reservoirs with hydraulic fracturing, or fracking.

Fracking has faced controversy across the country in recent years, with critics voicing concerns over the types of chemicals and amounts of water used in the extraction process, as well as complaints about emissions from production and potential land, air and water contamination. But carbon emissions linked to natural gas are nearly half that of coal.

Nuclear

Nuclear power harnesses the heat of radioactive materials to produce steam for power generation. The technology provides about 20 percent of the nation’s power through 100 generation units in the United States, but that figure is expected to decline as old plants are retired. Nuclear plants use large quantities of water and must be shut down every 18 to 24 months to remove and replace used uranium fuel rods. In 2008, U.S. uranium ore reserves were estimated at more than one billion pounds, with the reserves located primarily in Wyoming and New Mexico.

Sources: U.S. Energy Policy Coalition, naturalgas.org, U.S. Department of Energy, American Coalition for Clean Coal Electricity, National Mining Association, Dave Nulton, American Wind Energy Association, Union of Concerned Scientists, U.S. Environmental Protection Agency.