As the world develops and becomes more technologically advanced, energy sources will become increasingly important. No matter how advanced we become, if we don't have the energy sources to support our activities, they won't happen. In the past, we have relied heavily upon fossil fuels like coal, oil, and natural gas to support our energy needs. As fossil fuels run out, we will be looking to employ different energy sources such as renewable sources and nuclear sources, the technology for which is currently being developed.
The United States Department of Energy (DOE) publication ANNUAL ENERGY OUTLOOK 1995 projects that between now and the year 2010, world energy consumption will increase by approximately 19 percent from 1993. One goal will be to provide reliable energy sources for developing countries while protecting the environment. The DOE predicts that oil and coal will provide a smaller portion of the world's energy, while natural gas, solar, hydroelectric, biomass, and geothermal will provide a larger percentage. The major source of renewable energy for electricity generation is hydroelectric power, but because all our potential sites have already been developed, this cannot be expanded much in the United States. Nuclear energy use will grow at a much slower rate than the other energy sources due to concerns such as cost, safety, and radioactive waste. The use of nuclear energy by the United States to generate electricity past the year 2020 is uncertain because no new nuclear power plants have been built in the last ten years. Nuclear fusion is also a possible source of energy in the distant future. It is predicted that commercial production of energy by fusion will not occur for at least 30 years.