North America currently uses between 20 and 25 million barrels of oil per day.
2/3 is used for transportation fuel
1 barrel of oil yields roughly 20 gallons of gasoline.
The US uses just under 800,000 megawatts of power every day.
We burn about 20 trillion cubic feet of natural gas annually.
Breakdown of US energy usage
What are the current energy sources?
Fossil Fuels (coal, oil, natural gas)
Coal is mined from the earth’s crust.
a readily combustible black or brownish-black sedimentary rock.
Formed in ecosystems where plant remains were preserved by water and mud from oxidation and biodegradation.
Comprised primarily of carbon and hydrogen, and varying amounts of sulfur.
The Chinese mined coalstone for fuel 10,000 years ago at the time of the New Stone Age, or Neolithic Era.
Outcrop coal was used in Britain during the Bronze Age (2000-3000 years BC),
However, there is no evidence that the product was of great importance in Britain before the High Middle Ages, after about AD 1000.
The price of coal has gone up from around $30 per short ton in 2000 to around $123.50 per short ton as June 25th, 2008
World coal consumption is about 6.2 billion tons annually
about 75% is used for the production of electricity.
The environmental drawbacks to mining and burning coal.
release of carbon dioxide and methane
waste products including uranium, thorium, and other heavy metals
interference with groundwater and water table levels
subsidence above tunnels, sometimes damaging infrastructure
rendering land unfit for other uses.
coal-fired power plants without effective fly ash capture are one of the largest sources of human-caused background radiation exposure.
A naturally occurring, flammable liquid found in rock formations in the Earth consisting of a complex mixture of hydrocarbons of various molecular weights, plus other organic compounds.
Crude oil varies greatly in appearance - usually black or dark brown
Usually found in association with natural gas, and saline water
Crude oil may also be found in semi-solid form mixed with sand
Athabasca Oil Sands in Canada
84% by volume of the hydrocarbons present in petroleum is converted into energy-rich fuels (petroleum-based fuels)
gasoline, diesel, jet, heating, and other fuel oils
Due to its high energy density, easy transportability and relative abundance, it has become the world's most important source of energy since the mid-1950s.
The 16% not used for energy production is the raw material for many chemical products, including pharmaceuticals, solvents, fertilizers, pesticides, and plastics
Known reserves of petroleum are typically estimated at around 190 km3 (1.2 trillion barrels) without oil sands
Consumption is currently around 84 million barrels (13.4×106 m3) per day
At current consumption levels, known recoverable reserves would be gone around 2039
Estimate varies greatly
depending on source
Oil is formed from the preserved remains of prehistoric zooplankton and algea which have settled to the sea (or lake) bottom in large quantities under anoxic conditions.
Over geologic time this organic matter, mixed with mud, is buried under heavy layers of sediment.
High levels of heat and pressure cause the organic matter to chemically change during diagenesis,
first into a waxy material known as kerogen
then with more heat into liquid and gaseous hydrocarbons in a process known as catagenesis.
The presence of oil has significant social and environmental impacts
from accidents and routine activities such as seismic exploration, drilling, and generation of polluting wastes not produced by other alternative energies
Burning oil releases carbon dioxide (CO2) into the atmosphere
which is credited with contributing to global warming
Per joule, oil produces 15% less CO2 than coal, but 30% more than natural gas.
Natural gas is a gaseous fossil fuel consisting primarily of methane but including significant quantities of ethane, propane, butane, and pentane
as well as carbon dioxide, nitrogen, helium and hydrogen sulfide
In the United States, retail sales are often in units of therms (th)
1 therm = 100,000 BTU
It is found in oil fields or isolated in natural gas fields and in coal beds
When methane-rich gases are produced by the anaerobic of non-fossil organic material, these are referred to as biogas
Sources of biogas include swamps and landfills or sewage sludge and manure
Natural gas is a major source of electricity generation through the use of gas turbines and steam turbines.
Natural gas can be used to produce hydrogen
Natural gas is supplied to homes, where it is used for such purposes as in natural gas-powered ranges and/or ovens, clothes dryers, and heating/cooling
Natural gas is a major feedstock for the production of ammonia for use in fertilizer production
Natural gas also contains and is the primary market source of helium
Wind power is the conversion of wind energy into a useful form, such as electricity, using wind turbines.
The earliest historical reference describes a windmill used to power an organ in the 1st century AD.
Windmills were used extensively in Northwestern Europe to grind flour beginning in the 1180s, and many Dutch windmills still exist.
In the United States, the development of the "water-pumping windmill" was the major factor in allowing the farming and ranching of vast areas of North America, which were otherwise devoid of readily accessible water.
The origin of wind is complex.
The Earth is unevenly heated by the sun
the poles receiving less energy from the sun than the equator does.
the dry land heats up (and cools down) more quickly than the seas do.
The differential heating drives a global atmospheric convection system reaching from the Earth's surface to the stratosphere which acts as a virtual ceiling.
Electricity generated from wind power can be highly variable at several different timescales
from hour to hour, daily, and seasonally
this variability can present substantial challenges to incorporating large amounts of wind power into a grid system
Peak wind speeds may not coincide with peak demand for electrical power
Pumped storage hydroelectricity is a type of hydroelectric power generation used by some power plants for load balancing .
The method stores energy in the form of water, pumped from a lower elevation reservoir to a higher elevation.
Low-cost off-peak electric power is used to run the pumps.
During periods of high electrical demand, the stored water is released through turbines.
Although the losses of the pumping process makes the plant a net consumer of energy overall, the system increases revenue by selling more electricity during periods of peak demand , when electricity prices are highest .
In 2006 the United States produced/used 26.3 TWh
We consumed/produced a total of 4105 TWh in 2006
Had a total capacity of producing 11,603 MWh in 2006
The US has added more wind energy to its grid than any other country
Wind power capacity grew by 45% to 16.8 GW in 2007
Texas has become the largest wind energy producing state
Wind power consumes no fuel for continuing operation, and has no emissions directly related to electricity production.
Operation does not produce carbon dioxide, sulfur dioxide, mercury, particulates, or any other type of air pollution, as do fossil fuel power sources.
Wind power plants consume resources in manufacturing and construction.
During manufacture of the wind turbine, steel, concrete, aluminum and other materials will have to be made and transported using energy-intensive processes
Solar energy is the heat and light radiated from the Sun that powers Earth's climate and supports life
Solar power refers specifically to the conversion of sunlight into electricity by photovoltaics
The absorption of solar energy by atmospheric convection and evaporation and condensation of water vapor powers the water cycle and drives the winds.
Peak wind speeds may not coincide with peak demand for electrical power 174 PW coming in 10 PW reflected by Atmosphere 35 PW reflected by clouds 7 PW reflected by Earth’s surface 33 PW absorbed by Atmosphere 111 PW radiated to space by Atmosphere 10 PW radiated from earth to space 26 PW absorbed by Atmosphere 40 PW latent heat in water vapor 12 PW Conduction & rising air
A solar cell (or photovoltaic cell) is a device that converts light into direct current using the photoelectric effect
The photoelectric effect is a quantum electronic phenomenon in which electrons are emitted from matter after the absorption of energy from electromagnetic radiation such as x-rays or visible light
Photovoltaic cells became invaluable during the “space race” and made possible several significant satellites
Storage is an important issue in the development of solar energy
modern energy systems usually assume continuous availability of energy
Solar energy is not available at night, and the performance of solar power systems is affected by unpredictable weather patterns
storage media or back-up power systems must be used
Hydroelectricity is a form of hydropower
is the most widely used form of renewable energy
Hydroelectricity now supplies about 715,000 MWe or 19% of world electricity
Most hydroelectric power comes from the potential energy of dammed water driving a water turbine and generator.
The US creates 291.2 TW annually
The major advantage of hydroelectricity is elimination of the cost of fuel.
Since hydroelectric dams do not burn fossil fuels, they do not directly produce carbon dioxide
some carbon dioxide is produced during manufacture and construction of the project
Hydroelectric projects can be disruptive to surrounding aquatic ecosystems both upstream and downstream of the plant site
For instance, studies have shown that dams along the Atlantic and Pacific coasts of North American have reduced salmon populations
Water exiting a turbine usually contains very little suspended sediment, which can lead to scouring of river beds and loss of riverbanks
A further concern is the impact of major schemes on birds
Another disadvantage of hydroelectric dams is the need to relocate the people living where the reservoirs are planned
Failures of large dams, while rare, are potentially serious
Geothermal energy is heat from within the earth
We can use the steam and hot water produced inside the earth to heat buildings or generate electricity
Geothermal energy is a renewable energy source because the water is replenished by rainfall and the heat is continuously produced inside the earth
Geothermal energy is generated in the earth's core, about 4,000 miles below the surface
Temperatures hotter than the sun's surface are continuously produced inside the earth by the slow decay of radioactive particles
Geothermal energy can sometimes find its way to the surface in the form of:
volcanoes and fumaroles
holes where volcanic gases are released)
hot springs and
The three main uses of geothermal energy are:
Direct Use and District Heating Systems which use hot water from springs or reservoirs near the surface.
Electricity generation in a power plant requires water or steam at very high temperature
Geothermal power plants are generally built where geothermal reservoirs are located within a mile or two of the surface.
Geothermal heat pumps use stable ground or water temperatures near the earth's surface to control building temperatures above ground.
The direct use of hot water as an energy source has been happening since ancient times
After bathing, the most common direct use of geothermal energy is for heating buildings through district heating systems
Hot water near the earth's surface can be piped directly into buildings and industries for heat.
Geothermal plants require high temperature water sources
(300 to 700 degrees Fahrenheit)
hydrothermal resources that may come from either dry steam wells or hot water wells
We can use these resources by drilling wells into the earth and piping the steam or hot water to the surface
Geothermal wells are one to two miles deep
Geothermal heat pumps use the Earth's constant temperatures to heat and cool buildings
temperatures above ground change a lot from day to day and season to season
temperatures in the upper 10 feet of the Earth's surface hold nearly constant between 50 and 60 degrees Fahrenheit.
soil temperatures are usually warmer than the air in winter and cooler than the air in summer
They transfer heat from the ground (or water) into buildings in winter and reverse the process in the summer
Biomass refers to the burning or refining of plant materials to generate heat (directly) or electricity (indirectly)
Examples of biomass include:
Biomass currently supplies approximately 1,700 MW of power to the grid
0.5 percent of the U.S. electricity supply.
This level of biomass power generation avoids approximately 11 million tons per year of CO2 emissions from fossil fuel combustion
Draw backs to biomass include the release of greenhouse gasses as the fuel is burned
Food vs. Fuel debate
Using food sources as a fuel source
1/3 of the corn gown in the US is exported to other countries as a food source
Water resources needed to convert biomass to liquid fuel
Nuclear power is any nuclear technology designed to extract usable energy from atomic nuclei via controlled nuclear reactions
The most common method today is through nuclear fission
other methods include nuclear fusion and radioactive decay
All methods involve heating water, which is then converted by a turbine into electricity or propulsion
Today, more than 15% of the world's electricity comes from nuclear power
Over 150 nuclear-powered naval vessels have been built
Electricity was generated for the first time by a nuclear reactor on December 20, 1951 at the EBR-I experimental station near Arco, Idaho
initially produced about 100 kW
A general movement against nuclear power arose during the last third of the 20th century
based on the fear of a possible nuclear accident
fears of radiation
opposition to nuclear waste production
transport and final storage
In nuclear power plants the heat is provided by nuclear fission inside the nuclear reactor
When a relatively large fissile atomic nucleus is struck by a neutron it forms two or more smaller nuclei as fission products, releasing energy and neutrons in a process called nuclear fission
The neutrons then trigger further fission creating a chain reaction
When this nuclear chain reaction is controlled, the energy released can be used to heat water, produce steam and drive a turbine that generates electricity
The chain reaction is controlled through the use of materials that absorb and moderate neutrons
While a nuclear power plant uses the same fuel, uranium-235 or plutoniam-239, a nuclear explosive involves an uncontrolled chain reaction
(1) The Nuclear Fuel Cycle begins when uranium is mined, enriched, and manufactured into nuclear fuel
(2) Which is delivered to a nuclear power plant.
(3) After usage in the power plant, the spent fuel is delivered to a reprocessing plant or to a final repository for geological disposition
(4) In reprocessing 95% of spent fuel can be recycled to be returned to usage in a power plant
Spent fuel is highly radioactive and needs to be handled with great care and forethought
Spent fuel rods are stored in shielded basins of water (spent fuel pools), usually located on-site
After a few decades some on-site storage involves moving the fuel to a dry cask storage
where the fuel is stored in steel and concrete containers until its radioactivity decreases naturally
Nuclear power drastically reduces harmful emissions over fossil fuel based power plants
It is the most efficient power source we currently have
However, the potential for disaster is very high
The waste is very difficult to manage
Tidal power , sometimes called tidal energy , is a form of hydropower that converts the energy of tides into electricity or other useful forms of power
Tides are more predictable than wind energy and solar power
Tidal power can be classified into two main types:
Tidal stream systems make use of the kinetic energy of moving water to power turbines, in a similar way to windmills that use moving air
This method is gaining in popularity because of the lower cost and lower ecological impact compared to barrages.
Barrages make use of the potential energy in the difference in height between high and low tides
Barrages suffer from very high civil infrastructure costs, a worldwide shortage of viable sites, and environmental issues
Wave power refers to the energy of ocean surface waves and the capture of that energy to do useful work
Wave energy is produced when electricity generators are placed on the surface of the ocean.
The energy provided is most often used in desalination plants, power plants and water pumps.
Energy output is determined by wave height, wave speed, wavelength, and water density.
To date there are only a handful of experimental wave generator plants in operation around the world.
Portugal has built the world's first commercial wave farm
Made from corn oil, palm oil, soybean oil
Made from sugar cane, corn, miscanthus
Derived from landfills and animal waste
Brings up many issues
Food vs fuel
Using food supplies to generate energy
The need to develop abilities to create ethanol from cellulose
While biofuels reduce greenhouse gas emissions, they do not eliminate them