US Sources & Uses Of Energy
The chart at the left shows the 2013 total energy use in the US by its source. All data in this section comes from the Energy Information Administration (EIA) which is part of the Department Of Energy (DOE). The raw data is available in great detail. During 2013 there was very little change from 2012. Renewables increased by about a half of one percent and petroleum dropped about a half of one percent. Renewables can be further broken down as follows: Bio-mass - 4.7%, Hydro-electric Power - 2.6%, Wind - 1.6%, Solar - 0.3%, and Geo-thermal - 0.2%.
In 2013 the United States was the world leader in the production of petroleum, followed by Saudi Arabia and then Russia. However, we were also the largest consumer of petroleum (followed by China as a distant second) which has the negative consequence of being the largest contributor of carbon dioxide to greenhouse gases. U.S. total crude oil production, which averaged 7.4 million barrels per day (bbl/d ) in 2013, is expected to average 8.4 million bbl/d in 2014 and 9.3 million bbl/d in 2015. The 2015 forecast represents the highest annual level of oil production since the 1970s. The record U.S. production level was 9.6 million barrels per day in 1970.
Motor gasoline consumption grew by 90,000 barrels/day (1.1%) in 2013, the largest increase since 2006. Motor gasoline consumption is projected to grow another 30,000 barrels per day in 2014, but to decline by 10,000 barrels per day in 2015. The projected decline in 2015 is due to new vehicle fuel economy which offsets highway travel growth.
Natural gas production grew modestly in 2013 despite a 35% year over year increase in gas prices. Natural gas production grew from 65.7 billion cubic feet per day (Bcf/d) in 2012 to 66.5 Bcf/d in 2013, a 1% increase and the lowest annual growth since 2005. This production growth rate was essentially flat when compared to the 5% growth in 2012 and the 7% growth in 2011. In 2013 domestic natural gas consumption made up 96% of total U.S. gas production, the balance being exported.
The United States holds the world's largest reserves of coal and is a net exporter of coal. In 2013 U.S. coal mines produced just under one billion short tons of coal, the lowest output level since 1993. More than 90% of this coal was used by U.S. power plants to generate electricity.
Between 2000 and 2012, about 5% of the coal produced in the United States was exported to other countries. In 2013, the share of U.S. coal production that was exported increased to 12%, totaling 117.7 million short tons. However, the overall volume of coal exports declined by 6% from 125.7 million short tons in 2012.
There are currently 104 operational commercial nuclear reactors at 65 nuclear power plants. Since 1990, the share of the nation's total electricity provided by nuclear power has averaged about 20%, with increases in nuclear generation that roughly track the growth in total electricity output. Top
US Electricity By Source
While coal has been the largest source of electricity generation in the United States for over 60 years, its share of total generation has declined from 50% in 2007 to 39% in 2013. Although coal-fired generation is still number one, its use has declined due to slow growth in electricity demand, strong price competition from natural gas, increased use of renewable energies, and in particular new environmental regulations. There are currently no new coal-fired plants being built or planned.
In 2013 total natural gas consumption increased by 2% despite a decrease in consumption for electricity generation. Natural gas used for electrical power was 2.6 billion cubic feet per day below 2012 levels as coal regained some market share because of higher natural gas prices. Cooler summer temperatures in 2013 reduced total electric generation demand. However, increased natural gas winter heating demand due to cold weather offset the decline in summer electricity power, leading to the 2% net increase in consumption for the year.
The 1% use of oil for electricity generation occurs mainly in Hawaii because most of its energy must be imported.
The largest share of electricity generated by "renewable" sources in 2013 came from hydroelectric power (52%), followed by wind (32%), biomass wood (8%), biomass waste (4%), geothermal (3%), and solar (2%). Nearly all hydroelectric capacity was built before the mid-1970s, and most of it is at dams that are operated by federal agencies.
Biomass waste is mostly municipal solid waste that is burned in waste-to-energy power plants. Most electricity generation from wood biomass occurs at lumber and paper mills. These facilities use wood waste to provide much of their own steam and electricity needs.
The amount of electricity generated by wind has increased substantially in the past decade. This increase is largely attributed to the availability of federal financial incentives and renewable energy goals mandated by many state governments.
Unlike other sources of renewable electricity generation, solar generated a significant amount of power at small-scale installations. According to the EIA, these small solar installations (often located on private rooftops) are estimated to have generated about 10 billion kilowatt hours of electricity in 2013.
Approximately 27% of the energy used for electricity in the US is lost due to power production and grid transmission. The grid in the United States needs two major upgrades in the long run. First, we must switch all of our long distance transmission lines to high voltage which are much more efficient. Second, as more energy is derived from renewable sources, the grid must be able to store energy from the sun and wind. It has to have the intelligence to understand that excess energy from the sun and wind needs to be stored for night time use or for cloudy days. These are difficult problems, but they beg for solutions. Top
World Electricity By Source
Shown at the left is a projection by the EIA of world wide electricity generation. Liquids, mainly oil, are not an important source of fuel for electricity and remain in low usage over the next 25 years, decreasing about 12% (bright blue on the bottom of the bars in the chart at the left).
Coal, on the other hand, is currently the main source of fuel for electricity and will continue to be for the foreseeable future. In the industrial countries of the west, the use of coal will probably shrink a bit. However, in fast developing countries, like China and India, coal will increase as a source of fuel. However, both countries are making an effort to reduce their dependance on coal and are moving forward with renewables.
Renewables (solar, wind, hydro, and biomass) show the most increase - 130%. But sun and wind are variable and must be backed up by quick changes in generation which can only be natural gas. Natural gas is up 78% in the forecast and is the back up source of choice for renewables.
Nuclear is up 74% reflecting its low emissions profile and its ability to be available 90% of the time day or night. However, after the Japanese problems at Fukushima, many countries (lead by Germany) are re-thinking their nuclear strategies. EIA forecasts in the future will most likely show less growth for nuclear. Top
Sun And Wind Are Complementary
The chart at the left shows the sun and wind energy centers in the United States. The southwest is strong in solar and the Midwest is strong in wind. Also, solar energy is a daylight phenomenon whereas wind energy in the plains is strongest at night. Solar is stronger in the summer; winds are stronger in the winter.
Ken Zweibel of George Washington University has suggested building "super electrical highways" analogous to the interstate road system to supply electricity on high voltage transmission lines from the sources of sun and wind to far away places like Maine and the East Coast.
Electricity could be sent from Arizona to Maine with transmission losses of only 11% along these super electrical highways. Top
Solar Power Is Our Most Abundant Resource
The sun is our best source of energy by far. It dwarfs all other sources of power. The sun's total energy falling through the atmosphere to the earth in one year is approximately 4,000 times the current yearly energy usage by all of mankind. All the energy stored in the earth's reserves of coal, uranium, petroleum, and natural gas is equivalent to the energy from just 20 days of sunshine. Averaged over the entire surface of the earth, 24 hours per day for a year, each square meter collects the approximate energy equivalent of a barrel of oil each year. This converts to 4.2 kilowatt-hours of energy every day.
This average figure varies by location, season and weather patterns. Deserts, with very dry air and little cloud cover, average the most sun - more than 6 kilowatt-hours per day per square meter. Northern climes such as that of Boston, receive about 3.6 kilowatt-hours, which is 15% less than average. Sunlight varies by season and location as well, with some areas receiving very little sunshine in the winter. Seattle in December for example, receives only about 0.7 kilowatt-hours per day.