Solar heating is the usage of solar energy to provide process, space or water heating. See also Solar thermal energy. The heating of water is covered in solar hot water. Solar heating design is divided into two groups:

• Active solar heating uses pumps which move air or a liquid from the solar collector into the building or storage area.

• Passive solar heating does not require electrical or mechanical equipment, and may rely on the design and structure of the house to collect, store and distribute heat throughout the building (passive solar building design).

Wind power is the conversion of wind energy into a useful form, such as electricity, using wind turbines. At the end of 2007, worldwide capacity of wind-powered generators was 94.1 gigawatts. Although wind currently produces about 1% of world-wide electricity use,  it accounts for approximately 19% of electricity production in Denmark, 9% in Spain and Portugal, and 6% in Germany and the Republic of Ireland (2007 data). Globally, wind power generation increased more than fivefold between 2000 and 2007.^[1]

Most wind power is generated in the form of electricity. Large scale wind farms are connected to electrical grids. Individual turbines can provide electricity to isolated locations. In windmills, wind energy is used directly as mechanical energy for pumping water or grinding grain.

Wind energy is plentiful, renewable, widely distributed, clean, and reduces greenhouse gas emissions when it displaces fossil-fuel-derived electricity. The intermittency of wind seldom creates problems when using wind power to supply a low proportion of total demand. Where wind is to be used for a moderate fraction of demand, additional costs for compensation of intermittency are considered to be modest.

 

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, though other methods include nuclear fusion and radioactive decay. All utility-scale reactors ^[1] heat water to produce steam, which is then converted into mechanical work for the purpose of generating electricity or propulsion. Today, more than 15% of the world's electricity comes from nuclear power, more than 150 nuclear-powered naval vessels have been built, and a few radioisotope rockets have been produced.
 

Use

See also: Nuclear power by country and List of nuclear reactors

As of 2005, nuclear power provided 6.3% of the world's energy and 15% of the world's electricity, with the U.S., France, and Japan together accounting for 56.5% of nuclear generated electricity. As of 2007, the IAEA reported there are 439 nuclear power reactors in operation in the world, operating in 31 countries.

The United States produces the most nuclear energy, with nuclear power providing 19% of the electricity it consumes, while France produces the highest percentage of its electrical energy from nuclear reactors—78% as of 2006. In the European Union as a whole, nuclear energy provides 30% of the electricity. Nuclear energy policy differs between European Union countries, and some, such as Austria and Ireland, have no active nuclear power stations. In comparison, France has a large number of these plants, with 16 multi-unit stations in current use.

Many military and some civilian (such as some icebreaker) ships use nuclear marine propulsion, a form of nuclear propulsion. A few space vehicles have been launched using full-fledged nuclear reactors: the Soviet RORSAT series and the American SNAP-10A.

International research is continuing into safety improvements such as passively safe plants,^[9] the use of nuclear fusion, and additional uses of process heat such as hydrogen production (in support of a hydrogen economy), for desalinating sea water, and for use in district heating systems.

History

Origins

Nuclear fission was first experimentally achieved by Enrico Fermi in 1934 when his team bombarded uranium with neutrons. In 1938, German chemists Otto Hahn and Fritz Strassmann, along with Austrian physicists Lise Meitner and Meitner's nephew, Otto Robert Frisch, conducted experiments with the products of neutron-bombarded uranium. They determined that the relatively tiny neutron split the nucleus of the massive uranium atoms into two roughly equal pieces, which was a surprising result. Numerous scientists, including Leo Szilard who was one of the first, recognized that if fission reactions released additional neutrons, a self-sustaining nuclear chain reaction could result. This spurred scientists in many countries (including the United States, the United Kingdom, France, Germany, and the Soviet Union) to petition their government for support of nuclear fission research.

In the United States, where Fermi and Szilard had both emigrated, this led to the creation of the first man-made reactor, known as Chicago Pile-1, which achieved criticality on December 2, 1942. This work became part of the Manhattan Project, which built large reactors at the Hanford Site (formerly the town of Hanford, Washington) to breed plutonium for use in the first nuclear weapons. A parallel uranium enrichment effort also was pursued.

After World War II, the fear that reactor research would encourage the rapid spread of nuclear weapons and technology, combined with what many scientists thought would be a long road of development, created a situation in which reactor research was kept under strict government control and classification. In addition, most reactor research centered on purely military purposes.

Electricity was generated for the first time by a nuclear reactor on December 20, 1951 at the EBR-I experimental station near Arco, Idaho, which initially produced about 100 kW (the Arco Reactor was also the first to experience partial meltdown, in 1955). In 1952, a report by the Paley Commission (The President's Materials Policy Commission) for President Harry Truman made a "relatively pessimistic" assessment of nuclear power, and called for "aggressive research in the whole field of solar energy." A December 1953 speech by President Dwight Eisenhower, "Atoms for Peace," emphasized the useful harnessing of the atom and set the U.S. on a course of strong government support for international use of nuclear power.

Early years

In 1954, Lewis Strauss, then chairman of the United States Atomic Energy Commission (forerunner of the U.S. Nuclear Regulatory Commission and the United States Department of Energy) spoke of electricity in the future being "too cheap to meter." While few doubt he was thinking of atomic energy when he made the statement, he may have been referring to hydrogen fusion, rather than uranium fission.^[Actually, the consensus of government and business at the time was that nuclear (fission) power might eventually become merely economically competitive with conventional power sources.

On June 27, 1954, the USSRs Obninsk Nuclear Power Plant became the world's first nuclear power plant to generate electricity for a power grid, and produced around 5 megawatts electric power.

In 1955 the United Nations' "First Geneva Conference", then the world's largest gathering of scientists and engineers, met to explore the technology. In 1957 EURATOM was launched alongside the European Economic Community (the latter is now the European Union). The same year also saw the launch of the International Atomic Energy Agency (IAEA).

The world's first commercial nuclear power station, Calder Hall in Sellafield, England was opened in 1956 with an initial capacity of 50 MW (later 200 MW). The first commercial nuclear generator to become operational in the United States was the Shippingport Reactor (Pennsylvania, December, 1957).

One of the first organizations to develop nuclear power was the U.S. Navy, for the purpose of propelling submarines and aircraft carriers. It has a good record in nuclear safety, perhaps because of the stringent demands of Admiral Hyman G. Rickover, who was the driving force behind nuclear marine propulsion as well as the Shippingport Reactor. The U.S. Navy has operated more nuclear reactors than any other entity, including the Soviet Navy,^{[citation needed][dubious – discuss]} with no publicly known major incidents. The first nuclear-powered submarine, USS Nautilus (SSN-571), was put to sea in December 1954. Two U.S. nuclear submarines, USS Scorpion and USS Thresher, have been lost at sea. These vessels were both lost due to malfunctions in systems not related to the reactor plants. Also, the sites are monitored and no known leakage has occurred from the onboard reactors.

Enrico Fermi and Leó Szilárd in 1955 shared U.S. Patent 2,708,656  for the nuclear reactor, belatedly granted for the work they had done during the Manhattan Project.

Development

Installed nuclear capacity initially rose relatively quickly, rising from less than 1 gigawatt (GW) in 1960 to 100 GW in the late 1970s, and 300 GW in the late 1980s. Since the late 1980s worldwide capacity has risen much more slowly, reaching 366 GW in 2005. Between around 1970 and 1990, more than 50 GW of capacity was under construction (peaking at over 150 GW in the late 70s and early 80s) — in 2005, around 25 GW of new capacity was planned. More than two-thirds of all nuclear plants ordered after January 1970 were eventually cancelled.

During the 1970s and 1980s rising economic costs (related to extended construction times largely due to regulatory changes and pressure-group litigation) and falling fossil fuel prices made nuclear power plants then under construction less attractive. In the 1980s (U.S.) and 1990s (Europe), flat load growth and electricity liberalization also made the addition of large new baseload capacity unattractive.

The 1973 oil crisis had a significant effect on countries, such as France and Japan, which had relied more heavily on oil for electric generation (39% and 73% respectively) to invest in nuclear power. Today, nuclear power supplies about 80% and 30% of the electricity in those countries, respectively.

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, nuclear proliferation, and on the opposition to nuclear waste production, transport and final storage. Perceived risks on the citizens' health and safety, the 1979 accident at Three Mile Island and the 1986 Chernobyl disaster played a part in stopping new plant construction in many countries, although the public policy organization Brookings Institution suggests that new nuclear units have not been ordered in the U.S. because the Institution's research concludes they cost 15–30% more over their lifetime than conventional coal and natural gas fired plants.

Unlike the Three Mile Island accident, the much more serious Chernobyl accident did not increase regulations affecting Western reactors since the Chernobyl reactors were of the problematic RBMK design only used in the Soviet Union, for example lacking "robust" containment buildings. Many of these reactors are still in use today. However, changes were made in both the reactors themselves (use of low enriched uranium) and in the control system (prevention of disabling safety systems) to prevent the possibility of a duplicate accident.

An international organization to promote safety awareness and professional development on operators in nuclear facilities was created: WANO; World Association of Nuclear Operators.

Opposition in Ireland, New Zealand and Poland prevented nuclear programs there, while Austria (1978), Sweden (1980) and Italy (1987) (influenced by Chernobyl) voted in referendums to oppose or phase out nuclear power.

Future of the industry

See also: Nuclear energy policy, Mitigation of global warming, and Economics of new nuclear power plants

As of 2007, Watts Bar 1, which came on-line in 7 February 1996, was the last U.S. commercial nuclear reactor to go on-line. This is often quoted as evidence of a successful worldwide campaign for nuclear power phase-out. However, political resistance to nuclear power has only ever been successful in New Zealand, and parts of Europe and the Philippines. Even in the U.S. and throughout Europe, investment in research and in the nuclear fuel cycle has continued, and some experts predict that electricity shortages, fossil fuel price increases, global warming and heavy metal emissions from fossil fuel use, new technology such as passively safe plants, and national energy security will renew the demand for nuclear power plants.

Many countries remain active in developing nuclear power, including Japan, China and India, all actively developing both fast and thermal technology, South Korea and the United States, developing thermal technology only, and South Africa and China, developing versions of the Pebble Bed Modular Reactor (PBMR). Several EU member states actively pursue nuclear programs, while some other member states continue to have a ban for the nuclear energy use. Japan has an active nuclear construction program with new units brought on-line in 2005. In the U.S., three consortia responded in 2004 to the U.S. Department of Energy's solicitation under the Nuclear Power 2010 Program and were awarded matching funds—the Energy Policy Act of 2005 authorized loan guarantees for up to six new reactors, and authorized the Department of Energy to build a reactor based on the Generation IV Very-High-Temperature Reactor concept to produce both electricity and hydrogen. As of the early 21st century, nuclear power is of particular interest to both China and India to serve their rapidly growing economies—both are developing fast breeder reactors. See also energy development. In the energy policy of the United Kingdom it is recognized that there is a likely future energy supply shortfall, which may have to be filled by either new nuclear plant construction or maintaining existing plants beyond their programmed lifetime.

There is a possible impediment to production of nuclear power plants, due to a backlog at Japan Steel Works, the only factory in the world able to manufacture the central part of a nuclear reactor's containment vessel in a single piece, which reduces the risk of a radiation leak. The company can only make four per year of the steel forgings. It will double its capacity in the next two years, but still will not be able to meet current global demand alone. Utilities across the world are submitting orders years in advance of any actual need. Other manufacturers are examining various options, including making the component themselves, or finding ways to make a similar item using alternate methods. Other solutions include using designs that do not require single piece forged pressure vessles such as Canada's Advanced CANDU Reactors or Sodium-cooled Fast Reactors.

Other companies able to make the large forgings required for reactor pressure vessels include: Russia's OMZ, which is upgrading to be able to manufacture three or four pressure vessels per year; South Korea's Doosan Heavy Industries; and Mitsubishi Heavy Industries, which is doubling capacity for reactor pressure vessels and other large nuclear components. The UK's Sheffield Forgemasters is evaluating the benefit of tooling-up for nuclear forging work.

A 2007 status report from the anti-nuclear European Greens claimed that, "even if Finland and France build a European Pressurized water Reactor (EPR), China started an additional 20 plants and Japan, Korea or Eastern Europe added one or the other plant, the overall global trend for nuclear power capacity will most likely be downwards over the next two or three decades. With extremely long lead times of 10 years and more [for plant construction], it is practically impossible to maintain or even increase the number of operating nuclear power plants over the next 20 years, unless operating lifetimes would be substantially increased beyond 40 years on average." In fact, China plans to build more than 100 plants, while in the US the licenses of almost half its reactors have already been extended to 60 years, and plans to build more than 30 new ones are under consideration.

Nuclear reactor technology

Main article: Nuclear reactor technology

Conventional thermal power plants all have a fuel source to provide heat. Examples are gas, coal, or oil. For a nuclear power plant, this 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, and so on. 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. While a nuclear power plant uses the same fuel, uranium-235 or plutonium-239, a nuclear explosive involves an uncontrolled chain reaction, and the rate of fission in a reactor is not capable of reaching sufficient levels to trigger a nuclear explosion because commercial reactor grade nuclear fuel is not enriched to a high enough level. Naturally found uranium contains 0.711% U-235 by mass, the rest being U-238 and trace amounts of other isotopes. Most reactor fuel is enriched to only 3–4%, but some designs use natural uranium or highly enriched uranium. Reactors for nuclear submarines and large naval surface ships, such as aircraft carriers, commonly use highly enriched uranium. Although highly enriched uranium is more expensive, it reduces the frequency of refueling, which is very useful for military vessels. CANDU reactors are able to use unenriched uranium because the heavy water they use as a moderator and coolant does not absorb neutrons like light water does.

The chain reaction is controlled through the use of materials that absorb and moderate neutrons. In uranium-fueled reactors, neutrons must be moderated (slowed down) because slow neutrons are more likely to cause fission when colliding with a uranium-235 nucleus. Light water reactors use ordinary water to moderate and cool the reactors. When at operating temperatures if the temperature of the water increases, its density drops, and fewer neutrons passing through it are slowed enough to trigger further reactions. That negative feedback stabilizes the reaction rate.

The current types of plants (and their common components) are discussed in the article nuclear reactor technology.

A number of other designs for nuclear power generation, the Generation IV reactors, are the subject of active research and may be used for practical power generation in the future. A number of the advanced nuclear reactor designs could also make critical fission reactors much cleaner, much safer and/or much less of a risk to the proliferation of nuclear weapons.

It should be noted that such Generation IV reactors are not necessarily fuel by uranium but by thorium, a more abundant fertile material that decays into U233 after being exposed to neutrons. Such reactors use about 1/300 the amount of fuel to power them. The Liquid Fluoride Reactor is one such example of this.

For the future, design changes are being pursued to lessen the risks of fission reactors; in particular, passively safe plants (such as the ESBWR) are available to be built and inherently safe designs are being pursued. Fusion reactors, which may be viable in the future, have no risk of explosive radiation-releasing accidents, and even smaller risks than the already extremely small risks associated with nuclear fission. Whilst fusion power reactors will produce a very small amount of reasonably short lived, intermediate-level radioactive waste at decommissioning time, as a result of neutron activation of the reactor vessel, they will not produce any high-level, long-lived materials comparable to those produced in a fission reactor. Even this small radioactive waste aspect can be mitigated through the use of low-activation steel alloys for the tokamak vessel.

Life cycle

The Nuclear Fuel Cycle begins when uranium is mined, enriched, and manufactured into nuclear fuel, (1) which is delivered to a nuclear power plant. After usage in the power plant, the spent fuel is delivered to a reprocessing plant  or to a final repository  for geological disposition. In reprocessing 95% of spent fuel can be recycled to be returned to usage in a power plant. Main article: Nuclear fuel cycle

 United States of America

Main article: Nuclear power in the United States

Power station reactors

 NRC Region One (Northeast)

• Beaver Valley, Pennsylvania
• Calvert Cliffs, Maryland
• Connecticut Yankee, Connecticut (Decommissioned)
• FitzPatrick, New York
• Bear Creek, New York
• Hope Creek, New Jersey
• Indian Point, New York
• Limerick, Pennsylvania
• Maine Yankee, Maine (Decommissioned)
• Millstone, Connecticut
• Nine Mile Point, New York
• Oyster Creek, New Jersey
• Peach Bottom, Pennsylvania
• Pilgrim, Massachusetts
• Salem, New Jersey
• Saxton, Pennsylvania (Decommissioned)
• Seabrook, New Hampshire
• Shippingport, Pennsylvania (Decommissioned)
• Shoreham, New York (Decommissioned)
• Susquehanna, Pennsylvania
• Three Mile Island, Pennsylvania
• Vermont Yankee, Vermont
• Yankee Rowe, Massachusetts (Decommissioned)

 NRC Region Two (South)

• Bellefonte, Alabama (Unfinished)
• Browns Ferry, Alabama
• Brunswick, North Carolina
• Carolinas-Virginia Tube Reactor, South Carolina (decommissioned)
• Catawba, South Carolina
• Crystal River 3, Florida
• Farley (Joseph M. Farley), Alabama
• Grand Gulf Nuclear Generating Station, Mississippi
• Hatch (Edwin I. Hatch), Georgia
• McGuire, North Carolina
• North Anna, Virginia
• Oconee, South Carolina
• Virgil C. Summer, South Carolina
• Plant Vogtle, Georgia
• H.B. Robinson, South Carolina
• Sequoyah, Tennessee
• Shearon Harris, North Carolina
• St. Lucie, Florida
• Surry, Virginia
• Turkey Point, Florida (hit by Hurricane Andrew)
• Watts Bar, Tennessee

 NRC Region Three (Midwest)

• Byron, Illinois
• Braidwood, Illinois
• Clinton, Illinois
• Davis-Besse, Ohio
• Donald C. Cook, Michigan
• Dresden, Illinois
• Duane Arnold, Iowa
• Elk River, Minnesota (Decommissioned)
• Enrico Fermi, Michigan
• Kewaunee, Wisconsin
• La Crosse, Wisconsin (Decommissioned)
• LaSalle County, Illinois
• Marble Hill, Indiana (Unfinished)
• Monticello, Minnesota
• Palisades, Michigan
• Perry, Ohio
• Piqua, Ohio (Decommissioned)
• Point Beach, Wisconsin
• Prairie Island, Minnesota
• Quad Cities, Illinois
• Zion, Illinois (Decommissioned)

NRC Region Four (West)

• Arkansas Nuclear One, Arkansas
• Callaway, Missouri
• Columbia, Washington - formerly WNP-2
• Comanche Peak, Texas
• Cooper, Nebraska
• Diablo Canyon, California
• Fort Calhoun, Nebraska
• Fort Saint Vrain, Colorado (Decommissioned)
• Grand Gulf, Mississippi
• Hallam, Nebraska (Decommissioned)
• Hanford N Reactor, Washington (Retired - see Plutonium Production Reactors below)
• Humboldt Bay, California (Decommissioned)
• Palo Verde, Arizona
• Pathfinder, South Dakota (Decommissioned)
• Rancho Seco, California (Decommissioned)
• River Bend, Louisiana
• San Onofre, California
• Santa Susana, California (Closed 1957)
• South Texas, Texas
• Trojan, Rainier, Oregon (Decommissioned)
• UMR, Missouri
• Vallecitos, California (idle research center)
• Waterford, Louisiana
• Wolf Creek, Kansas

Plutonium production reactors

• Hanford Site, Washington
  • B-Reactor (Pile) - Preserved as a Museum
  • F-Reactor (Pile) - Cocooned
  • D-Reactor (Pile) - Cocooned
  • H-Reactor (Pile) - Being Cocooned
  • DR-Reactor (Pile) - Cocooned
  • C-Reactor (Pile) - Cocooned
  • KE-Reactor (Pile) - Being Cocooned
  • KW-Reactor (Pile) - Being Cocooned
  • N-Reactor - Being Cocooned
• Savannah River Site, South Carolina
  • R-Reactor (Heavy Water) - S&M Mode
  • P-Reactor (Heavy Water) - S&M Mode
  • L-Reactor (Heavy Water) - S&M Mode
  • K-Reactor (Heavy Water) - S&M Mode
  • C-Reactor (Heavy Water) - S&M Mode

Army Nuclear Power Program

Main article: Army Nuclear Power Program

• SM-1
• SM-1A
• PM-2A
• PM-1
• PM-3A
• MH-1A
• SL-1
• ML-1

 United States Naval reactors

Main article: List of United States Naval reactors

Research reactors

• Arkansas
  • SEFOR - Shut Down
• Argonne National Laboratory, Illinois (and Idaho)
  • CP-1 - Chicago Pile 1 - Shut Down
  • CP-2 - Chicago Pile 2 - Shut Down
  • CP-3 - Chicago Pile 3 - Shut Down
  • CP-5 - Chicago Pile 5 - Shut Down (1979)
  • EBWR - Experimental Boiling Water Reactor - Shut Down
  • LMFBR - Liquid Metal Fast Breeder Reactor - Shut Down
  • Janus reactor - Shut Down (1992)
  • JUGGERNAUT - Shut Down
  • IFR - Integral Fast Reactor - Never Operated (?)
• Brookhaven National Laboratory, Upton, New York
  • High Flux Beam Reactor - Shut Down (1999)
  • Medical Research Reactor - Shut Down (2000)
  • Brookhaven Graphite Research Reactor - Shut Down (1968)
• Hanford Site, Washington
  • Fast Flux Test Facility - currently in cold standby Core drilled
• Idaho National Laboratory, Idaho
  • ARMF-I - Shut Down
  • AMRF-II - Shut Down
  • ATR - Operating
  • ATRC - Operating
  • AFSR - Shut Down
  • BORAX-I - Shut Down
  • BORAX-II - Shut Down
  • BORAX-III - Shut Down
  • BORAX-IV - Shut Down
  • BORAX-V - Shut Down (1964)
  • CRCE - Shut Down
  • CFRMF - Shut Down
  • CET - Shut Down
  • ETR - Shut Down
  • ETRC - Shut Down
  • EBOR - Never Operated
  • EBR-I - Experimental Breeder Reactor I (originally CP-4) - Shut Down
  • EBR-II - Experimental Breeder Reactor II - Shut Down
  • ECOR - Never Operated
  • 710 - Shut Down
  • GCRE - Gas Cooled Reactor Experiment - Shut Down
  • HTRE-1 - Heat Transfer Reactor Experiment 1 - Shut Down
  • HTRE-2 - Heat Transfer Reactor Experiment 2 - Shut Down
  • HTRE-3 - Heat Transfer Reactor Experiment 3 - Shut Down
  • 603-A - Shut Down
  • HOTCE - Shut Down
  • A1W-A - Shut Down
  • A1W-B - Shut Down
  • LOFT - Shut Down
  • MTR - Shut Down
  • ML-1 - Mobil Low Power Plant - Shut Down
  • S5G - Shut Down
  • NRAD - Operating
  • FRAN - Shut Down
  • OMRE - Shut Down
  • PBF - Shut Down
  • RMF - Shut Down
  • SUSIE - Operational
  • SPERT-I - Shut Down
  • SPERT-II - Shut Down
  • SPERT-III - Shut Down
  • SPERT-IV - Shut Down
  • SCRCE - Shut Down
  • SL-1/ALPR - Stationary Low Power Plant - Shut Down
  • S1W/STR - Shut Down
  • SNAPTRAN-1 - Shut Down
  • SNAPTRAN-2 - Shut Down
  • SNAPTRAN-3 - Shut Down
  • THRITS - Shut Down
  • TREAT - Shut Down
  • ZPPR - Zero Power Physics Reactor (formerly Zero Power Plutonium Reactor) - Standby
  • ZPR-III - Shut Down
• Nevada Test Site, Nevada
  • BREN Tower
• Oak Ridge National Laboratory
  • X-10 Graphite Reactor - Shut Down
  • Oak Ridge Research Reactor - Shut Down
  • Bulk Shielding Reactor - Shut Down
  • Tower Shielding Reactor - Shut Down
  • Molten-Salt Reactor Experiment - Shut Down
  • High Flux Isotope Reactor - Operational
• Savannah River Site
  • HWCTR - Heavy Water Components Test Reactor - Partial Decommissioning

Civilian Research and Test Reactors Licensed To Operate

Operator	Location	Reactor	Power	Operational
Aerotest Operations Inc.	San Ramon, California	TRIGA Mark I	250 kW
Armed Forces Radiobiology Research Institute	Bethesda, Maryland	TRIGA Mark F	1 MW
Cornell University	Ithaca, New York	TRIGA Mark II	500 kW
Dow Chemical Company	Midland, Michigan	TRIGA Mark I	300 kW
General Electric Company	Sunol, California	"Nuclear Test"	100 kW
Idaho State University	Pocatello, Idaho	AGN-201 #103	50 W	1967
Kansas State University	Manhattan, Kansas	TRIGA Mark II	1250 kW	1962
Massachusetts Institute of Technology	Cambridge, Massachusetts	Tank Type HWR Reflected (MITR-II)	5 MW	1958 -
Missouri University of Science and Technology	Rolla, Missouri	Pool	200 kW	1961 -
National Institute of Standards and Technology	Gaithersburg, Maryland	TRIGA Mark I	20 MW
North Carolina State University	Raleigh, North Carolina	Pulstar	1 MW	1973 -
Ohio State University	Columbus, Ohio	Pool (modified Lockheed) [13]	500 kW	1961
Oregon State University	Corvallis, Oregon	TRIGA Mark II (OSTR)	1.1 MW	1967 -
Penn State University	University Park, Pennsylvania	TRIGA BNR Reactor	1.1 MW	1955 -
Purdue University	West Lafayette, Indiana	Lockheed	1 kW	1962
Reed College	Portland, OR	TRIGA Mark I (RRR)	250 kW	1968 -
Rensselaer Polytechnic Institute	Troy, New York	Critical Assembly
Rhode Island Atomic Energy Commission	Narragansett, Rhode Island	GE Pool	2 MW
Texas A&M University	College Station, TX	AGN-201M #106 - TRIGA Mark I (two reactors)	5 W, 1 MW
University of Arizona	Tucson, AZ	TRIGA Mark I	110 kW	1958
University of California-Berkeley	Berkeley, California	TRIGA Mark III (Shut Down)
University of California-Davis	Sacramento, California	TRIGA Mark II, McClellan Nuclear Radiation Center	2.3 MW	August 13, 1998 -
University of California, Irvine	Irvine, California	TRIGA Mark I	250 kW	1969
University of Florida	Gainesville, Florida	Argonaut (UFTR)	100 kW	1959 -
University of Maryland, College Park	College Park, Maryland	TRIGA Mark I	250 kW
University of Massachusetts Lowell	Lowell, Massachusetts	Pool	1 MW
University of Michigan	Ann Arbor, Michigan	Pool, Ford Nuclear Reactor (FNR)	2 MW	1957 - 2003
University of Missouri	Columbia, Missouri	General Electric tank type UMRR	10 MW	1966 -
University of New Mexico	Albuquerque, New Mexico	AGN-201M $112
University of Texas at Austin	Austin, Texas	TRIGA Mark II	1.1 MW
University of Utah	Salt Lake City, Utah	TRIGA Mark I	100 kW
University of Wisconsin-Madison	Madison, Wisconsin	TRIGA Mark I
U.S. Geological Survey	Denver, Colorado	TRIGA Mark I	1 MW
U.S. Veterans Administration	Omaha, Nebraska	TRIGA Mark I	20 kW
Washington State University	Pullman, Washington	TRIGA Mark I	1.3 MW	March 13, 1961 -
Worcester Polytechnic Institute	Worcester, Massachusetts	GE	10 kW

 Research and Test Reactors Under Decommission Orders or License Amendments

(These research and test reactors are authorized to decontaminate and dismantle their facility to prepare for final survey and license termination.)

• CBS Corporation, Waltz Mill, Pennsylvania
• General Atomics, San Diego, California (two reactors)
• Georgia Institute of Technology, Atlanta, Georgia
• Iowa State University, Ames, Iowa
• Manhattan College, Riverdale, New York
• National Aeronautics and Space Administration, Sandusky, Ohio (two reactors)
• Saxton Nuclear Experimental Corporation, Saxton, Pennsylvania (one power reactor)
• University of Illinois at Urbana-Champaign, Urbana, Illinois
• University of Washington, Seattle, Washington
• University of Virginia, Charlottesville, Virginia (two reactors)
• Westinghouse Electric Company, Waltz Mill, Pennsylvania

Research and Test Reactors With Possession-Only Licenses

(These research and test reactors are not authorized to operate the reactor, only to possess the nuclear material on-hand. They are permanently shut down.)

• Cornell University Zero Power Reactor, Ithaca, New York
• General Electric Company, Sunol, California (two research and test reactors, one power reactor)
• Nuclear Ship Savannah, James River Reserve Fleet, Virginia (one power reactor)
• University at Buffalo

 External links

• DoE list
• ICJT list—includes the defunct

Hydropower or hydraulic power is power that is derived from the force or energy of moving water, which may be harnessed for useful purposes.

Prior to the widespread availability of commercial electric power, hydropower was used for irrigation, and operation of various machines, such as watermills, textile machines, and sawmills. A trompe produces compressed air from falling water, which could then be used to power other machinery at a distance from the water.

History

Hydropower has been used for hundreds of years. In India, water wheels and watermills were built; in Imperial Rome, water powered mills produced flour from grain, and were also used for sawing timber and stone. The power of a wave of water released from a tank was used for extraction of metal ores in a method known as hushing. Hushing was widely used in Britain in the Medieval and later periods to extract lead and tin ores. It later evolved into hydraulic mining when used during the California gold rush.

In China and the rest of the Far East, hydraulically operated "pot wheel" pumps raised water into irrigation canals. In the 1830s, at the peak of the canal-building era, hydropower was used to transport barge traffic up and down steep hills using inclined plane railroads. Direct mechanical power transmission required that industries using hydropower had to locate near the waterfall. For example, during the last half of the 19th century, many grist mills were built at Saint Anthony Falls, utilizing the 50 foot (15 metre) drop in the Mississippi River. The mills contributed to the growth of Minneapolis. Hydraulic power networks also existed, using pipes carrying pressurized liquid to transmit mechanical power from a power source, such as a pump, to end users.

Today the largest use of hydropower is for the creation of hydroelectricity, which allows low cost energy to be used at long distances from the water source.

Natural manifestations

In hydrology, hydropower is manifested in the force of the water on the riverbed and banks of a river. It is particularly powerful when the river is in flood. The force of the water results in the removal of sediment and other materials from the riverbed and banks of the river, causing erosion and other alterations.

Types

There are several forms of water power:

• Waterwheels, used for hundreds of years to power mills and machinery
• Hydroelectricity, usually referring to hydroelectric dams, or run-of-the-river setups (eg hydroelectric-powered watermills).
• Damless hydro, which captures the kinetic energy in rivers, streams and oceans.
• Tidal power, which captures energy from the tides in horizontal direction
• Tidal stream power, which does the same vertically
• Vortex power, which creates vortices which can then be tapped for energy
• Wave power, which uses the energy in waves

Hydroelectric power

Main article: Hydroelectricity

Hydroelectric power now supplies about 715,000 MWe or 19% of world electricity (16% in 2003)^{[citation needed]}. Large dams are still being designed. The world's largest is the Three Gorges Dam on the third longest river in the world, the Yangtzi River. Apart from a few countries with an abundance of hydro power, this energy source is normally applied to peak load demand, because it is readily stopped and started. It also provides a high-capacity, low-cost means of energy storage, known as "pumped storage".

Resources in the United States

There is a common misconception that economically developed nations have harnessed all of their available hydropower resources. In the United States, according to the US Department of Energy, "previous assessments have focused on potential projects having a capacity of 1 MW and above". This may partly explain the discrepancy. More recently, in 2004, an extensive survey was conducted by the US-DOE which counted sources under 1 MW (mean annual average), and found that only 40% of the total hydropower potential had been developed. A total of 170 GW (mean annual average) remains available for development. Of this, 34% is within the operating envelope of conventional turbines, 50% is within the operating envelope of microhydro technologies (defined as less than 100 kW), and 16% is within the operating envelope of unconventional systems. ^[1] In 2005, the US generated 10¹² kilo-watt hours of electricity. The total undeveloped hydropower resource is equivalent to about one-third of total US electricity generation in 2005. Developed hydropower accounted for 6.4% of total US electricity generated in 2005.

Hydropower produces essentially no carbon dioxide or other harmful emissions, in contrast to burning fossil fuels, and is not a significant contributor to global warming through CO₂.

Hydroelectric power can be far less expensive than electricity generated from fossil fuels or nuclear energy. Areas with abundant hydroelectric power attract industry. Environmental concerns about the effects of reservoirs may prohibit development of economic hydropower sources.

The chief advantage of hydroelectric dams is their ability to handle seasonal (as well as daily) high peak loads. When the electricity demands drop, the dam simply stores more water (which provides more flow when it releases). Some electricity generators use water dams to store excess energy (often during the night), by using the electricity to pump water up into a basin. Electricity can be generated when demand increases. In practice the utilization of stored water in river dams is sometimes complicated by demands for irrigation which may occur out of phase with peak electrical demands.

Not all hydroelectric power requires a dam; a run-of-river project only uses part of the stream flow and is a characteristic of small hydropower projects. A developing technology example is the Gorlov helical turbine.

Tidal power

Main article: Tidal power

Harnessing the tides in a bay or estuary has been achieved in France (since 1966), Canada and Russia, and could be achieved in other areas with a large tidal range. The trapped water turns turbines as it is released through the tidal barrage in either direction. A possible fault is that the system would generate electricity most efficiently in bursts every six hours (once every tide). This limits the applications of tidal energy; tidal power is highly predictable but not able to follow changing electrical demand.

Tidal stream power

A relatively new technology, tidal stream generators draw energy from currents in much the same way that wind generators do. The higher density of water means that a single generator can provide significant power. This technology is at the early stages of development and will require more research before it becomes a significant contributor.

Several prototypes have shown promise. In the UK in 2003, a 300 kW Periodflow marine current propeller type turbine was tested off the coast of Devon, and a 150 kW oscillating hydroplane device, the Stingray, was tested off the Scottish coast. Another British device, the Hydro Venturi, is to be tested in San Francisco Bay.

The Canadian company Blue Energy has plans for installing very large arrays tidal current devices mounted in what they call a 'tidal fence' in various locations around the world, based on a vertical axis turbine design.

Wave power

Main article: Wave power

Harnessing power from ocean surface wave motion might yield much more energy than tides. The feasibility of this has been investigated, particularly in Scotland in the UK. Generators either coupled to floating devices or turned by air displaced by waves in a hollow concrete structure would produce electricity. Numerous technical problems have frustrated progress.

A prototype shore based wave power generator is being constructed at Port Kembla in Australia and is expected to generate up to 500 MWh annually. The Wave Energy Converter has been constructed (as of July 2005) and initial results have exceeded expectations of energy production during times of low wave energy. Wave energy is captured by an air driven generator and converted to electricity. For countries with large coastlines and rough sea conditions, the energy of waves offers the possibility of generating electricity in utility volumes. Excess power during rough seas could be used to produce hydrogen.

Physics

A hydropower resource can be measured according to the amount of available power, or energy per unit time. In large reservoirs, the available power is generally only a function of the hydraulic head and rate of fluid flow. In a reservoir, the head is the height of water in the reservoir relative to its height after discharge. Each unit of water can do an amount of work equal to its weight times the head.

The amount of energy released by lowering an object of mass by a height in a gravitational field is

where is the acceleration due to gravity.

The energy available to hydroelectric dams is the energy that can be liberated by lowering water in a controlled way. In these situations, the power is related to the mass flow rate.

Substituting for and expressing in terms of the volume of liquid moved per unit time (the rate of fluid flow ) and the density of water, we arrive at the usual form of this expression:

For in watts, is measured in kg/m³, is measured in m³/s, (standard gravity) is measured in m/s², and is measured in metres.

Some hydropower systems such as water wheels can draw power from the flow of a body of water without necessarily changing its height. In this case, the available power is the kinetic energy of the flowing water.

where is the velocity of the water,

or with where A is the area through which the water passes, also

Over-shot water wheels can efficiently capture both types of energy.

Small scale hydro power

Small scale hydro or micro-hydro power has been increasingly used as an alternative energy source, especially in remote areas where other power sources are not viable. Small scale hydro power systems can be installed in small rivers or streams with little or no discernible environmental effect on things such as fish migration. Most small scale hydro power systems make no use of a dam or major water diversion, but rather use water wheels.

There are some considerations in a micro-hydro system installation. The amount of water flow available on a consistent basis, since lack of rain can affect plant operation. Head, or the amount of drop between the intake and the exit. The more head, the more power that can be generated. There can be legal and regulatory issues, since most countries, cities, and states have regulations about water rights and easements.

Over the last few years, the U.S. Government has increased support for alternative power generation. Many resources such as grants, loans, and tax benefits are available for small scale hydro systems.

In poor areas, many remote communities have no electricity. Micro hydro power, with a capacity of 100 kW or less, allows communities to generate electricity¹. This form of power is supported by various organizations such as the UK's Practical Action.

Micro-hydro power can be used directly as "shaft power" for many industrial applications. Alternatively, the preferred option for domestic energy supply is to generate electricity with a generator or a reversed electric motor which, while less efficient, is likely to be available locally and cheaply.

See also

• Blue energy
• Damless hydro
• Deep lake water cooling
• Micro hydro
• Ocean thermal energy conversion
• Pico hydro
• Renewable energy
• Trompe

From Wikipedia, the free encyclopedia

Renewable energy

Biofuel can be broadly defined as solid, liquid, or gas fuel derived from recently dead biological material.This distinguishes it from fossil fuels, which are derived from long dead biological material. Biofuel can be theoretically produced from any (biological) carbon source, though the most common by far is photosynthetic plants. Many different plants and plant-derived materials are used for biofuel manufacture. Biofuels are used globally, most commonly to power vehicles and cooking stoves. Biofuel industries are expanding in Europe, Asia and the Americas.

Biofuels offer the possibility of producing energy without a net increase of carbon into the atmosphere because the plants used in to produce the fuel have removed CO₂ from the atmosphere, unlike fossil fuels which return carbon which was stored beneath the surface for millions of years into the air. Biofuel is therefore more nearly carbon neutral and less likely increase atmospheric concentrations of greenhouse gases (though doubts have been raised as to whether this benefit can be achieved in practice, see below). The use of biofuels also reduces dependence on petroleum and enhances energy security.

There are two common strategies of producing biofuels. One is to grow crops high in either sugar (sugar cane, sugar beet, and sweet sorghum) or starch (corn/maize), and then use yeast fermentation to produce ethyl alcohol (ethanol). The second is to grow plants that contain high amounts of vegetable oil, such as oil palm, soybean, algae, or jatropha. When these oils are heated, their viscosity is reduced, and they can be burned directly in a diesel engine, or the oils can be chemically processed to produce fuels such as biodiesel. Wood and its byproducts can also be converted into biofuels such as woodgas, methanol or ethanol fuel. It is also possible to make cellulosic ethanol from non-edible plant parts, but this can be difficult to accomplish economically.

Biofuels are discussed as having significant roles in a variety of international issues, including: mitigation of carbon emissions levels and oil prices, the "food vs fuel" debate, deforestation and soil erosion, impact on water resources, and energy balance and efficiency.

 History and policy

Humans have used biomass fuels in the form of solid biofuels for heating and cooking since the discovery of fire. Following the discovery of electricity, it became possible to use biofuels to generate electrical power as well. However, the discovery and use of fossil fuels: coal, gas and oil, have dramatically reduced the amount of biomass fuel used in the developed world for transport, heat and power. biofuels-p2.html National Geographic, Green Dreams, Oct 2007]  However, when large supplies of crude oil were discovered in Pennsylvania and Texas, petroleum based fuels became inexpensive, and soon were widely used. Cars and trucks began using fuels derived from mineral oil/petroleum: gasoline/petrol or diesel.

Nevertheless, before World War II, and during the high demand wartime period, biofuels were valued as a strategic alternative to imported oil. Wartime Germany experienced extreme oil shortages, and many energy innovations resulted. This includes the powering of some of its vehicles using a blend of gasoline with alcohol fermented from potatoes, called Monopolin.^{[citation needed]} In Britain, grain alcohol was blended with petrol by the Distillers Company Limited under the name Discol, and marketed through Esso's affiliate Cleveland.^{[citation needed]}

During the peacetime post-war period, inexpensive oil from the Middle East contributed in part to the lessened economic and geopolitical interest in biofuels. Then in 1973 and 1979, geopolitical conflict in the Middle East caused OPEC to cut exports, and non-OPEC nations experienced a very large decrease in their oil supply. This "energy crisis" resulted in severe shortages, and a sharp increase in the prices of high demand oil-based products, notably petrol/gasoline. There was also increased interest from governments and academics in energy issues and biofuels. Throughout history, the fluctuations of supply and demand, energy policy, military conflict, and the environmental impacts, have all contributed to a highly complex and volatile market for energy and fuel.

In the year 2000 and beyond, renewed interest in biofuels has been seen. The drivers for biofuel research and development include rising oil prices, concerns over the potential oil peak, greenhouse gas emissions (causing global warming and climate change), rural development interests, and instability in the Middle East.

Biomass

Main article: Biomass

Biomass is material derived from recently living organisms. This includes plants, animals and their by-products. For example, manure, garden waste and crop residues are all sources of biomass. It is a renewable energy source based on the carbon cycle, unlike other natural resources such as petroleum, coal, and nuclear fuels.

Animal waste is a persistent and unavoidable pollutant produced primarily by the animals housed in industrial sized farms. Researchers from Washington University have figured out a way to turn manure into biomass. In April 2008 with the help of imaging technology they noticed that vigorous mixing helps microorganisms turn farm waste into alternative energy, providing farmers with a simple way to treat their waste and convert it into energy.

There are also agricultural products specifically grown for biofuel production include corn, switchgrass, and soybeans, primarily in the United States; rapeseed, wheat and sugar beet primarily in Europe; sugar cane in Brazil; palm oil and miscanthus in South-East Asia; sorghum and cassava in China; and jatropha in India. Hemp has also been proven to work as a biofuel. Biodegradable outputs from industry, agriculture, forestry and households can be used for biofuel production, either using anaerobic digestion to produce biogas, or using second generation biofuels; examples include straw, timber, manure, rice husks, sewage, and food waste. The use of biomass fuels can therefore contribute to waste management as well as fuel security and help to prevent climate change, though alone they are not a comprehensive solution to these problems.

Bio energy from waste

Using waste biomass to produce energy can reduce the use of fossil fuels, reduce greenhouse gas emissions and reduce pollution and waste management problems. A recent publication by the European Union highlighted the potential for waste-derived bioenergy to contribute to the reduction of global warming. The report concluded that 19 million tons of oil equivalent is available from biomass by 2020, 46% from bio-wastes: municipal solid waste (MSW), agricultural residues, farm waste and other biodegradable waste streams.

Landfill sites generate gases as the waste buried in them undergoes anaerobic digestion. These gases are known collectively as landfill gas (LFG). This can be burned and is considered a source of renewable energy, even though landfill disposal are often non-sustainable. Landfill gas can be burned either directly for heat or to generate electricity for public consumption. Landfill gas contains approximately 50% methane, the same gas that is found in natural gas.

Biomass can come from waste plant material. If landfill gas is not harvested, it escapes into the atmosphere: this is not desirable because methane is a greenhouse gas, with more global warming potential than carbon dioxide. Over a time span of 100 years, methane has a global warming potential of 23 relative to CO₂. Therefore, during this time, one ton of methane produces the same greenhouse gas (GHG) effect as 23 tons of CO₂.^{[citation needed]} When methane burns the formula is CH₄ + 2O₂ = CO₂ + 2H₂O So by harvesting and burning landfill gas, its global warming potential is reduced a factor of 23, in addition to providing energy for heat and power.

Frank Keppler and Thomas Rockmann discovered that living plants also produce methane CH₄. The amount of methane produced by living plants is 10 to 100 times greater than that produced by dead plants (in an aerobic environment) but does not increase global warming because of the carbon cycle.

Anaerobic digestion can be used as a distinct waste management strategy to reduce the amount of waste sent to landfill and generate methane, or biogas. Any form of biomass can be used in anaerobic digestion and will break down to produce methane, which can be harvested and burned to generate heat, power or to power certain automotive vehicles.

A 3 MW landfill power plant would power 1,900 homes. It would eliminate 6,000 tons per year of methane from getting into the environment.^. It would eliminate 18,000 tons per year of CO₂ from fossil fuel replacement.^. This is the same as removing 25,000 cars from the road, or planting 36,000 acres (146 km²) of forest, or not using 305,000 barrels (48,500 m³) of oil per year.

Liquid fuels for transportation

Most transportation fuels are liquids, because vehicles usually require high energy density, as occurs in liquids and solids. Vehicles usually need high power density as can be provided most inexpensively by an internal combustion engine. These engines require clean burning fuels, in order to keep the engine clean and minimize air pollution. The fuels that are easier to burn cleanly are typically liquids and gases. Thus liquids (and gases that can be stored in liquid form) meet the requirements of being both portable and clean burning. Also, liquids and gases can be pumped, which means handling is easily mechanized, and thus less laborious.

Types of biofuels

 First generation biofuels

'First-generation biofuels' refer to biofuels made from sugar, starch, vegetable oil, or animal fats using conventional technology. The basic feedstocks for the production of first generation biofuels are often seeds or grains such as wheat, which yields starch that is fermented into bioethanol, or sunflower seeds, which are pressed to yield vegetable oil that can be used in biodiesel. These feedstocks could also enter the animal or human food chain, and as the global population has risen their use in producing biofuels has been criticised for diverting food away from the human food chain, leading to food shortages and price rises.

The most common first generation biofuels are listed below.

Vegetable oil

Main article: Vegetable oil used as fuel

Edible vegetable oil is generally not used as fuel, but lower quality oil can be used for this purpose. Used vegetable oil is increasingly being processed into biodiesel, or (less frequently) cleaned of water and particulates and used as a fuel. To ensure that the fuel injectors atomize the fuel in the correct pattern for efficient combustion, vegetable oil fuel must be heated to reduce its viscosity to that of diesel, either by electric coils or heat exchangers. This is easier in warm or temperate climates. MAN B&W Diesel, Wartsila and Deutz AG offer engines that are compatible with straight vegetable oil, without the need for after market modifications. Vegetable oil can also be used in many older diesel engines that do not use common rail or unit injection electronic diesel injection systems. Due to the design of the combustion chambers in indirect injection engines, these are the best engines for use with vegetable oil. This system allows the relatively larger oil molecules more time to burn. However, a number of drivers have successfully experimented with earlier pre- "pumpe duse" VW TDI engines and other similar engines with direct injection.

Biodiesel

Main articles: Biodiesel and Biodiesel around the world

Biodiesel is the most common biofuel in Europe. It is produced from oils or fats using transesterification and is a liquid similar in composition to fossil/mineral diesel. Its chemical name is fatty acid methyl (or ethyl) ester (FAME). Oils are mixed with sodium hydroxide and methanol (or ethanol) and the chemical reaction produces biodiesel (FAME) and glycerol. One part glycerol is produced for every 10 parts biodiesel. Feedstocks for biodiesel include animal fats, vegetable oils, soy, rapeseed, jatropha, mahua, mustard, flax, sunflower, palm oil, hemp, field pennycress, and algae. Pure biodiesel (B100) is by far the lowest emission diesel fuel. Although liquefied petroleum gas and hydrogen have cleaner combustion, they are used to fuel much less efficient petrol engines and are not as widely available.

Biodiesel can be used in any diesel engine when mixed with mineral diesel. The majority of vehicle manufacturers limit their recommendations to 15% biodiesel blended with mineral diesel. In some countries manufacturers cover their diesel engines under warranty for B100 use, although Volkswagen of Germany, for example, asks drivers to make a telephone check with the VW environmental services department before switching to B100. B100 may become more viscous at lower temperatures, depending on the feedstock used, requiring vehicles to have fuel line heaters. In most cases biodiesel is compatible with diesel engines from 1994 onwards, which use 'Viton' (by DuPont) synthetic rubber in their mechanical injection systems. Electronically controlled 'common rail' and 'pump duse' type systems from the late 90s onwards (whose finely metered and atomized multi-stage injection systems are very sensitive to the viscosity of the fuel), may only use biodiesel blended with conventional diesel fuel. Many of the current generation of diesel engines are made so that they can run on B100 without altering the engine itself, although this can be dependent on the fuel rail design.

Since biodiesel is an effective solvent and cleans residues deposited by mineral diesel, engine filters may need to be replaced more often as the biofuel dissolves old deposits in the fuel tank and pipes. It also effectively cleans the engine combustion chamber of carbon deposits, helping to maintain efficiency. In many European countries, a 5% biodiesel blend is widely used and is available at thousands of gas stations. Biodiesel is also an oxygenated fuel, meaning that it contains a reduced amount of carbon and higher hydrogen and oxygen content than fossil diesel. This improves the combustion of fossil diesel and reduces the particulate emissions from un-burnt carbon.

In the USA, more than 80% of commercial trucks and city buses run on diesel. Therefore there is an emerging U.S. biodiesel market, estimated to have grown 200 percent from 2004 to 2005. "By the end of 2006 biodiesel production was estimated to increase fourfold [from 2004] to more than 1 billion gallons,".

Bioalcohols

Main article: Alcohol fuel

Biologically produced alcohols, most commonly ethanol, and less commonly propanol and butanol, are produced by the action of microorganisms and enzymes through the fermentation of sugars or starches (easiest), or cellulose (which is more difficult). Biobutanol (also called biogasoline) is often claimed to provide a direct replacement for gasoline, because it can be used directly in a gasoline engine (in a similar way to biodiesel in diesel engines).

Butanol is formed by ABE fermentation (acetone, butanol, ethanol) and experimental modifications of the process show potentially high net energy gains with butanol as the only liquid product. Butanol will produce more energy and allegedly can be burned "straight" in existing gasoline engines (without modification to the engine or car), and is less corrosive and less water soluble than ethanol, and could be distributed via existing infrastructures. DuPont and BP are working together to help develop Butanol.

Ethanol fuel is the most common biofuel worldwide, particularly in Brazil. Alcohol fuels are produced by fermentation of sugars derived from wheat, corn, sugar beets, sugar cane, molasses and any sugar or starch that alcoholic beverages can be made from (like potato and fruit waste, etc.). The ethanol production methods used are enzyme digestion (to release sugars from stored starches, fermentation of the sugars, distillation and drying. The distillation process requires significant energy input for heat (often unsustainable natural gas fossil fuel, but cellulosic biomass such as bagasse, the waste left after sugar cane is pressed to extract its juice, can also be used more sustainably).

Ethanol can be used in petrol engines as a replacement for gasoline; it can be mixed with gasoline to any percentage. Most existing automobile petrol engines can run on blends of up to 15% bioethanol with petroleum/gasoline. Gasoline with ethanol added has higher octane, which means that your engine can typically burn hotter and more efficiently. In high altitude (thin air) locations, some states mandate a mix of gasoline and ethanol as a winter oxidizer to reduce atmospheric pollution emissions.

Ethanol fuel has less BTU energy content, which means it takes more fuel (volume and mass) to go the same distance. More-expensive premium fuels contain less, or no, ethanol. In high-compression engines, less ethanol, slower-burning premium fuel is required to avoid harmful pre-ignition (knocking). Very-expensive aviation gasoline (Avgas) is 100 octane made from 100% petroleum. The high price of zero-ethanol Avgas does not include federal-and-state road-use taxes.

Ethanol is very corrosive to fuel systems, rubber hoses-and-gaskets, aluminum, and combustion chambers. It is therefore illegal to use fuels containing alcohol in aircraft (although at least one model of ethanol-powered aircraft has been developed, the Embraer EMB 202 Ipanema). Ethanol is incompatible with marine fiberglass fuel tanks (it makes them leak). For higher ethanol percentage blends, and 100% ethanol vehicles, engine modifications are required.

Corrosive ethanol cannot be transported in petroleum pipelines, so more-expensive over-the-road stainless-steel tank trucks increase the cost and energy consumption required to deliver ethanol to the customer at the pump.

In the current alcohol-from-corn production model in the United States, considering the total energy consumed by farm equipment, cultivation, planting, fertilizers, pesticides, herbicides, and fungicides made from petroleum, irrigation systems, harvesting, transport of feedstock to processing plants, fermentation, distillation, drying, transport to fuel terminals and retail pumps, and lower ethanol fuel energy content, the net energy content value added and delivered to consumers is very small. And, the net benefit (all things considered) does little to reduce un-sustainable imported oil and fossil fuels required to produce the ethanol.

Many car manufacturers are now producing flexible-fuel vehicles (FFV's), which can safely run on any combination of bioethanol and petrol, up to 100% bioethanol. They dynamically sense exhaust oxygen content, and adjust the engine's computer systems, spark, and fuel injection accordingly. This adds initial cost and ongoing increased vehicle maintenance. Efficiency falls and pollution emissions increase when FFV system maintenance is needed (regardless of the 0%-to-100% ethanol mix being used), but not performed (as with all vehicles). FFV internal combustion engines are becoming increasingly complex, as are multiple-propulsion-system FFV hybrid vehicles, which impacts cost, maintenance, reliability, and useful lifetime longevity

Alcohol mixes with both petroleum and with water, so ethanol fuels are often diluted after the drying process by absorbing environmental moisture from the atmosphere. Water in alcohol-mix fuels reduces efficiency, makes engines harder to start, causes intermittent operation (sputtering), and oxidizes aluminum (carburetors) and steel components (rust).

Even dry ethanol has roughly one-third lower energy content per unit of volume compared to gasoline, so larger / heavier fuel tanks are required to travel the same distance, or more fuel stops are required. With large current un-sustainable, non-scalable subsidies, ethanol fuel still costs much more per unit of distance traveled than current high gasoline prices in the United States.

Methanol is currently produced from natural gas, a non-renewable fossil fuel. It can also be produced from biomass as biomethanol. The methanol economy is an interesting alternative to the hydrogen economy, compared to today's hydrogen produced from natural gas, but not hydrogen production directly from water and state-of-the-art clean solar thermal energy processes.

BioGas

Main article: biogas

Biogas is produced by the process of anaerobic digestion of organic material by anaerobes. It can be produced either from biodegradable waste materials or by the use of energy crops fed into anaerobic digesters to supplement gas yields. The solid byproduct, digestate, can be used as a biofuel or a fertilizer. In the UK, the National Coal Board experimented with microorganisms that digested coal in situ converting it directly to gases such as methane.

Biogas contains methane and can be recovered from industrial anaerobic digesters and mechanical biological treatment systems. Landfill gas is a less clean form of biogas which is produced in landfills through naturally occurring anaerobic digestion. If it escapes into the atmosphere it is a potent greenhouse gas.

Oils and gases can be produced from various biological wastes:

• Thermal depolymerization of waste can extract methane and other oils similar to petroleum.
• GreenFuel Technologies Corporation developed a patented bioreactor system that uses nontoxic photosynthetic algae to take in smokestacks flue gases and produce biofuels such as biodiesel, biogas and a dry fuel comparable to coal.

Solid biofuels

Examples include wood, grass cuttings, domestic refuse, charcoal, and dried manure.

Syngas

Main article: Gasification

Syngas is produced by the combined processes of pyrolysis, combustion, and gasification. Biofuel is converted into carbon monoxide and energy by pyrolysis. A limited supply of oxygen is introduced to support combustion. Gasification converts further organic material to hydrogen and additional carbon monoxide.

The resulting gas mixture, syngas, is itself a fuel. Using the syngas is more efficient than direct combustion of the original biofuel; more of the energy contained in the fuel is extracted.

Syngas may be burned directly in internal combustion engines. The wood gas generator is a wood-fueled gasification reactor mounted on an internal combustion engine. Syngas can be used to produce methanol and hydrogen, or converted via the Fischer-Tropsch process to produce a synthetic petroleum substitute. Gasification normally relies on temperatures >700°C. Lower temperature gasification is desirable when co-producing biochar.

Second generation biofuels

Main article: Second generation biofuels

Supporters of biofuels claim that a more viable solution is to increase political and industrial support for, and rapidity of, second-generation biofuel implementation from non food crops, including cellulosic biofuels.^[18] Second-generation biofuel production processes can use a variety of non food crops. These include waste biomass, the stalks of wheat, corn, wood, and special-energy-or-biomass crops (e.g. Miscanthus). Second generation (2G) biofuels use biomass to liquid technology, including cellulosic biofuels from non food crops.^[19] Many second generation biofuels are under development such as biohydrogen, biomethanol, DMF, Bio-DME, Fischer-Tropsch diesel, biohydrogen diesel, mixed alcohols and wood diesel.

Cellulosic ethanol production uses non food crops or inedible waste products and does not divert food away from the animal or human food chain. Lignocellulose is the "woody" structural material of plants. This feedstock is abundant and diverse, and in some cases (like citrus peels or sawdust) it is a significant disposal problem.

Producing ethanol from cellulose is a difficult technical problem to solve. In nature, Ruminant livestock (like cattle) eat grass and then use slow enzymatic digestive processes to break it into glucose (sugar). In cellulosic ethanol laboratories, various experimental processes are being developed to do the same thing, and then the sugars released can be fermented to make ethanol fuel.

Scientists also work on experimental recombinant DNA genetic engineering organisms that could increase biofuel potential.

 Third generation biofuels

Main article: Algae fuel

Algae fuel, also called oilgae or third generation biofuel, is a biofuel from algae. Algae are low-input/high-yield (30 times more energy per acre than land) feedstocks to produce biofuels and algae fuel are biodegradable:

• With the higher prices of fossil fuels (petroleum), there is much interest in algaculture (farming algae).

• One advantage of many biofuels over most other fuel types is that they are biodegradable, and so relatively harmless to the environment if spilled.

• The United States Department of Energy estimates that if algae fuel replaced all the petroleum fuel in the United States, it would require 15,000 square miles (38,849 square kilometers), which is roughly the size of Maryland.

Second and third generation biofuels are also called advanced biofuels.

On the other hand, an appearing fourth generation is based in the conversion of vegoil and biodiesel into gasoline.

Fourth generation biofuels

Craig Venter's company Synthetic Genomics is genetically engineering microorganisms to produce fuel directly from carbon dioxide on an industrial scale.

Biofuels by country

Recognizing the importance of implementing bioenergy, there are international organizations such as IEA Bioenergy, established in 1978 by the OECD International Energy Agency (IEA), with the aim of improving cooperation and information exchange between countries that have national programs in bioenergy research, development and deployment. The U.N. International Biofuels Forum is formed by Brazil, China, India, South Africa, the United States and the European Commission. The world leaders in biofuel development and use are Brazil, United States, France, Sweden and Germany.

See also: Biodiesel around the world

Israel

IC Green Energy, a subsidiary of Israel Corp., aims by 2012 to process 4-5% of the global biofuel market (~4 million tons). It is focused solely on non-edible feedstock such as Jatropha, Castor, cellulosic biomass and algae. In June 2008, Tel Aviv-based Seambiotic and Seattle-based Inventure Chemical announced a joint venture to use CO2 emissions-fed algae to make ethanol and biodiesel at a biofuel plant in Israel.

China

In China, the government is making E10 blends mandatory in five provinces that account for 16% of the nation's passenger cars. In Southeast Asia, Thailand has mandated an ambitious 10% ethanol mix in gasoline starting in 2007. For similar reasons, the palm oil industry plans to supply an increasing portion of national diesel fuel requirements in Malaysia and Indonesia.  In Canada, the government aims for 45% of the country’s gasoline consumption to contain 10% ethanol by 2010.

India

Main article: Biofuels in India

In India, a bioethanol program calls for E5 blends throughout most of the country targeting to raise this requirement to E10 and then E20.

Europe

The European Union in its biofuels directive (updated 2006) has set the goal that for 2010 that each member state should achieve at least 5.75% biofuel usage of all used traffic fuel. By 2020 the figure should be 10%. As of January 2008 these aims are being reconsidered in light of certain environmental and social concerns associated with biofuels such as rising food prices and deforestation.

France

France is the second largest biofuel consumer among the EU States in 2006. According to the Ministry of Industry, France's consumption increased by 62.7% to reach 682,000 toe (i.e. 1.6% of French fuel consumption). Biodiesel represents the largest share of this (78%, far ahead of bioethanol with 22%). The unquestionable biodiesel leader in Europe is the French company Diester Industrie. In bioethanol, the French agro-industrial group Téréos is increasing its production capacities. Germany itself remained the largest European biofuel consumer, with a consumption estimate of 2.8 million tons of biodiesel (equivalent to 2,408,000 toe), 0.71 million ton of vegetable oil (628.492 toe) and 0.48 million ton of bioethanol (307,200 toe).

 Germany

The biggest biodiesel German company is ADM Ölmühle Hamburg AG, which is a subsidiary of the American group Archer Daniels Midland Company. Among the other large German producers, MUW (Mitteldeutsche Umesterungswerke GmbH & Co KG) and EOP Biodiesel AG. A major contender in terms of bioethanol production is the German sugar corporation, Südzucker.

Spain

The Spanish group Abengoa, via its American subsidiary Abengoa Bioenergy, is the European leader in production of bioethanol.

Sweden

Main article: Biofuel in Sweden

The government in Sweden has together with BIL Sweden, the national association for the automobile industry, that are the automakers in Sweden started the work to end oil dependency. One-fifth of cars in Stockholm can run on alternative fuels, mostly ethanol fuel. Also Stockholm will introduce a fleet of Swedish-made hybrid ethanol-electric buses. In 2005, oil phase-out in Sweden by 2020 was announced.

United Kingdom

In the United Kingdom the Renewable Transport Fuel Obligation (RTFO) (announced 2005) is the requirement that by 2010 5% of all road vehicle fuel is renewable. In 2008 a critical report by the Royal Society stated that biofuels risk failing to deliver significant reductions in greenhouse gas emissions from transport and could even be environmentally damaging unless the Government puts the right policies in place.

Brazil

Main article: Biofuel in Brazil

In Brazil, the government hopes to build on the success of the Proálcool ethanol program by expanding the production of biodiesel which must contain 2% biodiesel by 2008, increasing to 5% by 2013.

Colombia

Colombia mandates the use of 10% ethanol in all gasoline sold in cities with populations exceeding 500,000. In Venezuela, the state oil company is supporting the construction of 15 sugar cane distilleries over the next five years, as the government introduces a E10 (10% ethanol) blending mandate.

USA

Main article: Biofuel in the United States

In 2006, the United States president George W. Bush said in a State of the Union speech that the US is "addicted to oil" and should replace 75% of imported oil by 2025 by alternative sources of energy including biofuels.

Essentially all of the ethanol fuel in the US is produced from corn. Corn is a very energy intensive crop, which requires one unit of fossil-fuel energy to create just 0.9 to 1.3 energy units of ethanol.^[36] A senior member of the House Energy and Commerce Committee Congressman Fred Upton has introduced legislation to use at least E10 fuel by 2012 in all cars in the USA.

The 2007-12-19 U.S. Energy Independence and Security Act of 2007 requires American “fuel producers to use at least 36 billion gallons of biofuel in 2022. This is nearly a fivefold increase over current levels.”^[37] This is causing a significant agricultural resource shift away from food production to biofuels. American food exports have decreased (increasing grain prices worldwide), and US food imports have increased significantly.

Most biofuels are not currently cost-effective without significant subsidies. "America's ethanol program is a product of government subsidies. There are more than 200 different kinds, as well as a 54 cents-a-gallon tariff on imported ethanol. This prices Brazilian ethanol out of an otherwise competitive market. Brazil makes ethanol from sugarcane rather than corn (maize), which has a better EROEI. Federal subsidies alone cost $7 billion a year (equal to around $1.90 a gallon)."

General Motors is starting a project to produce E85 fuel from cellulose ethanol for a projected cost of $1 a gallon. This is optimistic however, because $1/gal equates to $10/MBTU which is comparable to woodchips at $7/MBTU or cord wood at $6-$12/MBTU, and this does not account for conversion losses and plant operating and capital costs which are significant. The raw materials can be as simple as corn stalks and scrap petroleum-based vehicle tires, but used tires are an expensive feedstock with other more-valuable uses. GM has over 4 million E85 cars on the road now, and by 2012 half of the production cars for the U.S. will be capable of running on E85 fuel, however by 2012 the supply of ethanol will not even be close to supplying this much E85. Coskata Inc. is building two new plants for the ethanol fuel. Theoretically, the process is claimed to be five times more energy efficient than corn based ethanol, however it is still in development and has not been proven to be cost effective in a free market.

The greenhouse gas emissions are reduced by 86% for cellulose compared to corn’s 29% reduction.

Biofuels in developing countries

Biofuel industries are becoming established in many developing countries. Many developing countries have extensive biomass resources that are becoming more valuable as demand for biomass and biofuels increases. The approaches to biofuel development in different parts of the world varies. Countries such as India and China are developing both bioethanol and biodiesel programs. India is extending plantations of jatropha, an oil-producing tree that is used in biodiesel production. The Indian sugar ethanol program sets a target of 5% bioethanol incorporation into transport fuel China is a major bioethanol producer and aims to incorporate 15% bioethanol into transport fuels by 2010. Costs of biofuel promotion programs can be very high, though.

Amongst rural populations in developing countries, biomass provides the majority of fuel for heat and cooking. Wood, animal dung and crop residues are commonly burned. Figures from the International Energy Agency show that biomass energy provides around 30% of the total primary energy supply in developing countries; over 2 billion people depend on biomass fuels as their primary energy source.

The use of biomass fuels for cooking indoors is a source of health problems and pollution. 1.3 million deaths were attributed to the use of biomass fuels with inadequate ventilation by the International Energy Agency in its World Energy Outlook 2006. Proposed solutions include improved stoves and alternative fuels. However, fuels are easily damaged, and alternative fuels tend to be expensive. Very low cost, fuel efficient, low pollution biomass stove designs have existed since 1980 or earlier.^[43] Issues are a lack of education, distribution, excess corruption, and very low levels of foreign aid. People in developing countries are often unable to afford these solutions without assistance or financing such as microloans. Organizations such as Intermediate Technology Development Group work to make improved facilities for biofuel use and better alternatives accessible to those who cannot get them.

Current issues in biofuel production and use

Biofuels are proposed as having such benefits as: reduction of greenhouse gas emissions, reduction of fossil fuel use, increased national energy security, increased rural development and a sustainable fuel supply for the future.

However, biofuel production is questioned from a number of angles. The chairman of the International Panel on Climate Change, Rajendra Pachauri, notably observed in March 2008 that questions arise on the emissions implications of that route, and that biofuel production has clearly raised prices of corn, with an overall implication for food security.

Biofuels are also seen as having limitations. The feedstocks for biofuel production must be replaced rapidly and biofuel production processes must be designed and implemented so as to supply the maximum amount of fuel at the cheapest cost, while providing maximum environmental benefits. Broadly speaking, first generation biofuel production processes cannot supply us with more than a few percent of our energy requirements sustainably. The reasons for this are described below. Second generation processes can supply us with more biofuel, with better environmental gains. The major barrier to the development of second generation biofuel processes is their capital cost: establishing second generation biodiesel plants has been estimated at €500million.

Recently, an inflexion point about advantages/disadvantages of biofuels seems to be gaining momentum. The March 27, 2008 TIME magazine cover features the subject under the title "The Clean Energy Myth":

Politicians and Big Business are pushing biofuels like corn-based ethanol as alternatives to oil. All they’re really doing is driving up world food prices, helping to destroy the Amazon jungle, and making global warming worse.

In the June, 2008 issue of the journal Conservation Biology, scientists argue that because such large amounts of energy are required to grow corn and convert it to ethanol, the net energy gain of the resulting fuel is modest. Using a crop such as switchgrass, common forage for cattle, would require much less energy to produce the fuel, and using algae would require even less. Changing direction to biofuels based on switchgrass or algae would require significant policy changes, since the technologies to produce such fuels are not fully developed.

Oil price moderation

The International Energy Agency's World Energy Outlook 2006 concludes that rising oil demand, if left unchecked, would accentuate the consuming countries' vulnerability to a severe supply disruption and resulting price shock. The report suggested that biofuels may one day offer a viable alternative, but also that "the implications of the use of biofuels for global security as well as for economic, environmental, and public health need to be further evaluated".

Economists disagree on the extent that biofuel production affects crude oil prices. According to the Francisco Blanch, a commodity strategist for Merrill Lynch, crude oil would be trading 15 per cent higher and gasoline would be as much as 25 per cent more expensive, if it were not for biofuels. Gordon Quaiattini, president of the Canadian Renewable Fuels Association, argued that a healthy supply of alternative energy sources will help to combat gasoline price spikes. However, the Federal Reserve Bank of Dallas concluded that "Biofuels are too limited in scale and currently too costly to make much difference to crude oil pricing."

Rising food prices — the "food vs. fuel" debate

Main article: food vs fuel

This topic is internationally controversial. There are those, such as the National Corn Growers Association, who say biofuel is not the main cause. Some say the problem is a result of government actions to support biofuels. Others say it is just due to oil price increases. The impact of food price increases is greatest on poorer countries. Some have called for a freeze on biofuels. Some have called for more funding of second generation biofuels which should not compete with food production so much. In May 2008 Olivier de Schutter, the United Nations food adviser, called for a halt on biofuel investment. In an interview in Le Monde he stated: "The ambitious goals for biofuel production set by the United States and the European Union are irresponsible. I am calling for a freeze on all investment in this sector." 100 million people are currently at risk due to the food price increases.

Carbon emissions

Biofuels and other forms of renewable energy aim to be carbon neutral or even carbon negative. Carbon neutral means that the carbon released during the use of the fuel, e.g. through burning to power transport or generate electricity, is reabsorbed and balanced by the carbon absorbed by new plant growth. These plants are then harvested to make the next batch of fuel. Carbon neutral fuels lead to no net increases in human contributions to atmospheric carbon dioxide levels, reducing the human contributions to global warming. A carbon negative aim is achieved when a portion of the biomass is used for carbon sequestration. Calculating exactly how much greenhouse gas (GHG) is produced in burning biofuels is a complex and inexact process, which depends very much on the method by which the fuel is produced and other assumptions made in the calculation.

Carbon emissions have been increasing ever since the industrial revolution. Prior to the industrial revolution, our atmosphere contained about 280 parts per million of carbon dioxide. After burning coal, gas, and oil to power our lives, the concentration had risen to 315 parts per million. Today, it is at the 380 level and still increasing by approximately two parts per million annually. During this time frame, the global average temperature has risen by more than 1°F since carbon dioxide traps heat near the Earth’s surface. Scientists believe that if the level goes beyond 450 parts per million, the temperature jump will be so great that we will be faced with an enormous rise in sea level due to the melting of Greenland and West Antarctic ice sheets.

The carbon emissions (Carbon footprint) produced by biofuels are calculated using a technique called Life Cycle Analysis (LCA). This uses a "cradle to grave" or "well to wheels" approach to calculate the total amount of carbon dioxide and other greenhouse gases emitted during biofuel production, from putting seed in the ground to using the fuel in cars and trucks. Many different LCAs have been done for different biofuels, with widely differing results. The majority of LCA studies show that biofuels provide significant greenhouse gas emissions savings when compared to fossil fuels such as petroleum and diesel.^{[citation needed]} Therefore, using biofuels to replace a proportion of the fossil fuels that are burned for transportation can reduce overall greenhouse gas emissions. The well-to-wheel analysis for biofuels has shown that first generation biofuels can save up to 60% carbon emission and second generation biofuels can save up to 80% as opposed to using fossil fuels. However these studies do not take into account emissions from nitrogen fixation, deforestation, land use, or any indirect emissions.

In October 2007, a study was published by scientists from Britain, U.S., Germany and Austria, including Professor Paul Crutzen, who won a Nobel Prize for his work on ozone. They reported that the burning of biofuels derived from rapeseed and corn (maize) can contribute as much or more to global warming by nitrous oxide emissions than cooling by fossil fuel savings. Nitrous oxide is both a potent greenhouse gas and a destroyer of atmospheric ozone. But they also reported that crops with lower requirements for nitrogen fertilizers, such as grasses and woody coppicing will result in a net absorption of greenhouse gases.

In February 2008, two articles were published in Science which investigated the GHG emissions effects of the large amount of natural land that is being converted to cropland globally to support biofuels development. The first of these studies, conducted at the University of Minnesota, found that:

...converting rainforests, peatlands, savannas, or grasslands to produce food-based biofuels in Brazil, Southeast Asia, and the United States creates a ‘biofuel carbon debt’ by releasing 17 to 420 times more CO₂ than the annual greenhouse gas (GHG) reductions these biofuels provide by displacing fossil fuels.

This study not only takes into account removal of the original vegetation (as timber or by burning) but also the biomass present in the soil, for example roots, which is released on continued plowing. It also pointed out that:

...biofuels made from waste biomass or from biomass grown on degraded and abandoned agricultural lands planted with perennials incur little or no carbon debt and can offer immediate and sustained GHG advantages.

The second study, conducted at Princeton University, used a worldwide agricultural model to show that:

...corn-based ethanol, instead of producing a 20% savings, nearly doubles greenhouse emissions over 30 years and increases greenhouse gases for 167 years.

Both of the Science studies highlight the need for sustainable biofuels, using feedstocks that minimize competition for prime croplands. These include farm, forest and municipal waste streams; energy crops grown on marginal lands, and algaes. These second generation biofuels feedstocks "are expected to dramatically reduce GHGs compared to first generation biofuels such as corn ethanol". In short, biofuels done unsustainably could make the climate problem worse, while biofuels done sustainably could play a leading role in solving the carbon challenge.

Sustainable biofuel production

Main article: Sustainable biofuel

Responsible policies and economic instruments would help to ensure that biofuel commercialization, including the development of new cellulosic technologies, is sustainable. Sustainable biofuel production practices would not hamper food and fibre production, nor cause water or environmental problems, and would actually enhance soil fertitlity. Responsible commercialization of biofuels represents an opportunity to enhance sustainable economic prospects in Africa, Latin America and impoverished Asia.

Soil erosion, deforestation, and biodiversity

It is important to note that carbon compounds in waste biomass that is left on the ground are consumed by other microorganisms. They break down biomass in the soil to produce valuable nutrients that are necessary for future crops. On a larger scale, plant biomass waste provides small wildlife habitat, which in turn ripples up through the food chain. The widespread human use of biomass (which would normally compost the field) would threaten these organisms and natural habitats. When cellulosic ethanol is produced from feedstock like switchgrass and saw grass, the nutrients that were required to grow the lignocellulose are removed and cannot be processed by microorganisms to replenish the soil nutrients. The soil is then of poorer quality. Loss of ground cover root structures accelerates unsustainable soil erosion.

Significant areas of native Amazon rainforest have been cleared by slash and burn techniques to make room for sugar cane production, which is used in large part for ethanol fuel in Brazil, and growing ethanol exports. Large-scale deforestation of mature trees (which help remove CO₂ through photosynthesis — much better than does sugar cane or most other biofuel feedstock crops do) contributes to un-sustainable global warming atmospheric greenhouse gas levels, loss of habitat, and a reduction of valuable biodiversity. Demand for biofuel has led to clearing land for Palm Oil plantations.

A portion of the biomass should be retained onsite to support the soil resource. Normally this will be in the form of raw biomass, but processed biomass is also an option. If the exported biomass is used to produce syngas, the process can be used to co-produce biochar, a low-temperature charcoal used as a soil amendment to increase soil organic matter to a degree not practical with less recalcitrant forms of organic carbon. For co-production of biochar to be widely adopted, the soil amendment and carbon sequestration value of co-produced charcoal must exceed its net value as a source of energy.

Impact on water resources

Increased use of biofuels puts increasing pressure on water resources in at least two ways: water use for the irrigation of crops used as feedstocks for biodiesel production; and water use in the production of biofuels in refineries, mostly for boiling and cooling.

In many parts of the world supplemental or full irrigation is needed to grow feedstocks. For example, if in the production of corn (maize) half the water needs of crops are met through irrigation and the other half through rainfall, about 860 liters of water are needed to produce one liter of ethanol.

In the United States, the number of ethanol factories has almost tripled from 50 in 2000 to about 140 in 2008. A further 60 or so are under construction, and many more are planned. Projects are being challenged by residents at courts in Missouri (where water is drawn from the Ozark Aquifer), Iowa, Nebraska, Kansas (all of which draw water from the non-renewable Ogallala Aquifer), central Illinois (where water is drawn from the Mahomet Aquifer) and Minnesota.

Aldehydes

Formaldehyde, Acetaldehyde and other Aldehydes are produced when alcohols are oxidized. When only a 10% mixture of ethanol is added to gasoline (as is common in American E10 gasohol and elsewhere), aldehyde emissions increase 40%. Some study results are conflicting on this fact however, and lowering the sulfur content of biofuel mixes lowers the acetaldehyde levels. Burning biodiesel also emits aldehydes and other potentially hazardous aromatic compounds which are not regulated in emissions laws.

Many aldehydes are toxic to living cells. Formaldehyde irreversibly cross-links protein amino acids, which produces the hard flesh of embalmed bodies. At high concentrations in an enclosed space, formaldehyde can be a significant respiratory irritant causing nose bleeds, respiratory distress, lung disease, and persistent headaches. Acetaldehyde, which is produced in the body by alcohol drinkers and found in the mouths of smokers and those with poor oral hygene, is carcinogenic and mutagenic.

The European Union has banned products that contain Formaldehyde, due to its documented carcinogenic characteristics. The U.S. Environmental Protection Agency has labeled Formaldehyde as a probable cause of cancer in humans.

Brazil burns significant amounts of ethanol biofuel. Gas chromatograph studies were performed of ambient air in São Paulo Brazil, and compared to Osaka Japan, which does not burn ethanol fuel. Atmospheric Formaldehyde was 160% higher in Brazil, and Acetaldehyde was 260% higher.

Social and Water impact in Indonesia

In some locations such as Indonesia deforestation for Palm Oil plantations is leading to displacement of Indigenous peoples. Also, extensive use of pesticide for biofuel crops is reducing clean water supplies.

Environmental organizations stance

Some mainstream environmental groups support biofuels as a significant step toward slowing or stopping global climate change.^{[citation needed]} However, biofuel production can threaten the environment if it is not done sustainably. This finding has been backed by reports of the UN, the IPCC, and some other smaller environmental and social groups as the EEB and the Bank Sarasin, which generally remain negative about biofuels.

As a result, governmentaland environmental organisations are turning against biofuels made at a non-sustainable way (hereby preferring certain oil sources as jatropha and lignocellulose over palm oil) and are asking for global support for this. Also, besides supporting these more sustainable biofuels, environmental organisations are redirecting to new technologies that do not use internal combustion engines such as hydrogen and compressed air.

The "Roundtable on Sustainable Biofuels" is an international initiative which brings together farmers, companies, governments, non-governmental organizations, and scientists who are interested in the sustainability of biofuels production and distribution. During 2008, the Roundtable is developing a series of principles and criteria for sustainable biofuels production through meetings, teleconferences, and online discussions.

The increased manufacture of biofuels will require increasing land areas to be used for agriculture. Second and third generation biofuel processes can ease the pressure on land, because they can use waste biomass, and existing (untapped) sources of biomass such as crop residues and potentially even marine algae.

In some regions of the world, a combination of increasing demand for food, and increasing demand for biofuel, is causing deforestation and threats to biodiversity. The best reported example of this is the expansion of oil palm plantations in Malaysia and Indonesia, where rainforest is being destroyed to establish new oil palm plantations. It is an important fact that 90% of the palm oil produced in Malaysia is used by the food industry; therefore biofuels cannot be held solely responsible for this deforestation. There is a pressing need for sustainable palm oil production for the food and fuel industries; palm oil is used in a wide variety of food products. The Roundtable on Sustainable Biofuels is working to define criteria, standards and processes to promote sustainably produced biofuels. Palm oil is also used in the manufacture of detergents, and in electricity and heat generation both in Asia and around the world (the UK burns palm oil in coal-fired power stations to generate electricity).

Significant area is likely to be dedicated to sugar cane in future years as demand for ethanol increases worldwide. The expansion of sugar cane plantations will place pressure on environmentally-sensitive native ecosystems including rainforest in South America. In forest ecosystems, these effects themselves will undermine the climate benefits of alternative fuels, in addition to representing a major threat to global biodiversity.

Although biofuels are generally considered to improve net carbon output, biodiesel and other fuels do produce local air pollution, including nitrogen oxides, the principal cause of smog.

Potential for poverty reduction

Researchers at the Overseas Development Institute have argued that biofuels could help to reduce poverty in the developing world, through increased employment, wider economic growth multipliers and energy price effects. However, this potential is described as 'fragile', and is reduced where feedstock production tends to be large scale, or causes pressure on limited agricultural resources: capital investment, land, water, and the net cost of food for the poor.

With regards to the potential for poverty reduction or exacerbation, biofuels rely on many of the same policy, regulatory or investment shortcomings that impede agriculture as a route to poverty reduction. Since many of these shortcomings require policy improvements at a country level rather than a global one, they argue for a country-by-country analysis of the potential poverty impacts of biofuels. This would consider, among other things, land administration systems, market coordination and prioritising investment in biodiesel, as this 'generates more labour, has lower transportation costs and uses simpler technology'.

 Biofuel prices

Retail, at the pump prices, including U.S. subsidies, Federal and state motor taxes, B2/B5 prices for low-level Biodiesel (B2-B5) are lower than petroleum diesel by about 12 cents, and B20 blends are the same per unit of volume as petrodiesel.

Due to the 1/3 lower energy content of ethanol fuel, even the heavily-subsidized net cost to drive a specific distance in flexible-fuel vehicles is higher than current gasoline prices.

Energy efficiency and energy balance of biofuels

Production of biofuels from raw materials requires energy (for farming, transport and conversion to final product, and the production / application of fertilizers, pesticides, herbicides, and fungicides), and has environmental consequences.

The energy balance of a biofuel is determined by the amount of energy put into the manufacture of fuel compared to the amount of energy released when it is burned in a vehicle. This varies by feedstock and according to the assumptions used. Biodiesel made from sunflowers may produce only 0.46 times the input rate of fuel energy. Biodiesel made from soybeans may produce 3.2 times the input rate of fossil fuels. This compares to 0.805 for gasoline and 0.843 for diesel made from petroleum. Biofuels may require higher energy input per unit of BTU energy content produced than fossil fuels: petroleum can be pumped out of the ground and processed more efficiently than biofuels can be grown and processed. However, this is not necessarily a reason to use oil instead of biofuels, nor does it have an impact on the environmental benefits provided by a given biofuel.

Studies have been done that calculate energy balances for biofuel production. Some of these show large differences depending on the biomass feedstock used and location.

To explain one specific example, a June 17, 2006 editorial in the Wall. St. Journal stated, "The most widely cited research on this subject comes from Cornell's David Pimental and Berkeley's Ted Patzek. They've found that it takes more than a gallon of fossil fuel to make one gallon of ethanol — 29% more. That's because it takes enormous amounts of fossil-fuel energy to grow corn (using fertilizer and irrigation), to transport the crops and then to turn that corn into ethanol."^]

Life cycle assessments of biofuel production show that under certain circumstances, biofuels produce only limited savings in energy and greenhouse gas emissions. Fertiliser inputs and transportation of biomass across large distances can reduce the GHG savings achieved. The location of biofuel processing plants can be planned to minimize the need for transport, and agricultural regimes can be developed to limit the amount of fertiliser used for biomass production. A European study on the greenhouse gas emissions found that well-to-wheel (WTW) CO₂ emissions of biodiesel from seed crops such as rapeseed could be almost as high as fossil diesel. It showed a similar result for bio-ethanol from starch crops, which could have almost as many WTW CO₂ emissions as fossil petrol. This study showed that second generation biofuels have far lower WTW CO₂ emissions.

Other independent LCA studies show that biofuels save around 50% of the CO₂ emissions of the equivalent fossil fuels. This can be increased to 80-90% GHG emissions savings if second generation processes or reduced fertiliser growing regimes are used. Further GHG savings can be achieved by using by-products to provide heat, such as using bagasse to power ethanol production from sugarcane.

Collocation of synergistic processing plants can enhance efficiency. One example is to use the exhaust heat from an industrial process for ethanol production, which can then recycle cooler processing water, instead of evaporating hot water that warms the atmosphere.

Biofuels and solar energy efficiency

Biofuels from plant materials convert energy that was originally captured from solar energy via photosynthesis. A comparison of conversion efficiency from solar to usable energy (taking into account the whole energy budgets) shows that photovoltaics are 100 times more efficient than corn ethanol^[104] and 10 times more efficient than the best biofuel

Centralised vs. decentralised production

There is debate around the best model for production.

One side sees centralised vegetable oil fuel production offering

• efficiency
• greater potential for fuel standardisation
• ease of administrating taxes
• possibility for rapid expansion

The other side of the argument points to

• increased fuel security
• rural job creation
• less of a 'monopolistic' or 'oligopolistic' market due to the increased number of producers
• benefits to local economy as a greater part of any profits stay in the local economy
• decreased transportation and greenhouse gases of feedstock and end product
• consumers close to and able to observe the effects of production

The majority of established biofuel markets have followed the centralised model with a few small or micro producers holding a minor segment of the market. A noticeable exception to this has been the pure plant oil (PPO) market in Germany which grew exponentially until the beginning of 2008 when increasing feedstock prices and the introduction of fuel duty combined to stifle the market. Fuel was produced in hundreds of small oil mills distributed throughout Germany often run as part of farm businesses.

Initially fuel quality could be variable but as the market matured new technologies were developed that made significantly improvements. As the technologies surrounding this fuel improved usage and production rapidly increased with rapeseed oil PPO forming a significant segment of transportation biofuels consumed in 2007.

See also

Category:Biofuel by country Algaculture and algology Anaerobic digestion Biobutanol, a direct biofuel that replaces gasoline. Biodiesel Bioenergy Biofuel in Brazil Biofuel in Sweden Biofuel in the United States Biofuelwatch Biogas and Biogas powerplant Bioheat, a biofuel blended with heating oil. Biohydrogen Biomass to liquid bio-oil Directive on the Promotion of the use of biofuels and other renewable fuels for transport Energy crop Energy density

Energy Policy Act of 2005 Energy security Ecological sanitation and biogas. Energy content of biofuel Ethanol fuel European Biofuels Technology Platform[106] Food, Conservation, and Energy Act of 2008 Gasification Green crude Hybrid vehicle List of emerging technologies List of vegetable oils section on oils used as biodiesel Low-carbon economy Straight vegetable oil United Nations Environment Programme (UNEP) Vegetable oil economy Waste vegetable oil