Environmental design Environmental design is the process of addressing surrounding environmental parameters when devising plans, programs, policies, buildings, or products. It seeks to create spaces that will enhance the natural, social, cultural and physical environm ...

is an emerging topic in

railroad Rail transport (also known as train transport) is a means of transport using wheeled vehicles running in railway track, tracks, which usually consist of two parallel steel railway track, rails. Rail transport is one of the two primary means of ...

technology. From the 1980s to 2009,

fuel efficiency Fuel efficiency (or fuel economy) is a form of thermal efficiency, meaning the ratio of effort to result of a process that converts chemical energy, chemical potential energy contained in a carrier (fuel) into kinetic energy or Mechanical work, w ...

in diesel locomotives in the USA has increased 85%, allowing these trains to go farther and move more freight while using less fuel. New low-impact

electric Electricity is the set of physical phenomena associated with the presence and motion of matter possessing an electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by Maxwel ...

and hybrid trains reduce overall carbon emissions. Also, train manufacturers have started utilizing hydrogen technology for propulsion, with carbon emissions only coming from the manufacturing of the hydrogen itself.

Increasing efficiency while lowering emissions

Diesel trains

Diesel trains replaced the steam engine in the late 1920s as a cleaner more efficient way of moving people and goods. Since 1980, the amount of freight being hauled by Diesel Trains has nearly doubled, yet the fuel consumption of trains has virtually stayed the same. Estimates have shown that about of fuel have been saved by increasing the efficiency in diesel trains. US Department of Energy reported that commercial airline energy intensity was , automobiles were , while commuter rail energy intensity was just , which indicates that rail transportation is the most energy efficient of the three. The Union Pacific Rail Road has implemented a particle filter on their diesel engines. Silicon carbide blocks trap particles from the exhaust as they leave the engine, greatly reducing emissions.

Electric trains

Electric trains have always had no direct carbon emissions because they are run entirely by internal electric motors. However, the means of generating the electricity used to power these motors was predominately by burning fossil fuels or coal, both of which produce a large amount of carbon emissions. With the emergence of 'clean energy' generation, electrical trains actually run with very low environmental impact. For example, the proposal for the high-speed rail line between

San Francisco San Francisco, officially the City and County of San Francisco, is a commercial, Financial District, San Francisco, financial, and Culture of San Francisco, cultural center of Northern California. With a population of 827,526 residents as of ...

and

Los Angeles Los Angeles, often referred to by its initials L.A., is the List of municipalities in California, most populous city in the U.S. state of California, and the commercial, Financial District, Los Angeles, financial, and Culture of Los Angeles, ...

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

has the potential for zero

greenhouse gas emissions Greenhouse gas (GHG) emissions from human activities intensify the greenhouse effect. This contributes to climate change. Carbon dioxide (), from burning fossil fuels such as coal, petroleum, oil, and natural gas, is the main cause of climate chan ...

, with the 3,350 GWh each year being generated by California's extensive infrastructure of renewable energy sources.

Hybrid trains

Since 1986, engineers have been developing electric-diesel "hybrid" trains. One type of hybrid train implements battery power when the train is idling and at low speed movement, and a diesel engine at higher speeds. To recharge the batteries, power from the diesel motor, charge utilizing

regenerative braking Regenerative braking is an energy recovery mechanism that slows down a moving vehicle or object by converting its kinetic energy or potential energy into a form that can be either used immediately or stored until needed. Typically, regenerativ ...

, or a combination of both is used. According to the

Institute of Electrical and Electronics Engineers The Institute of Electrical and Electronics Engineers (IEEE) is an American 501(c)(3) public charity professional organization for electrical engineering, electronics engineering, and other related disciplines. The IEEE has a corporate office ...

, hybrid trains reduce the carbon emissions of Diesel Trains by 19%. Another type of hybrid train, such as the RailPower Technologies Green Goat, uses a large battery, and a small set of generators ("genset") for power. The genset is run at a constant speed and is attached to a generator to replenish the battery.

Hydrail

Hydrogen propulsion is an emerging technology, and is currently being implemented in locomotives. Hydrogen-powered trains dubbed "

Hydrail In transportation, the original (2003) generic term "hydrail" includes hydrogen trains, zero-emission multiple units, or ZEMUs—generic terms describing rail vehicles, large or small, which use on-board hydrogen fuel as a source of energy to po ...

" emit only water as a by product of combustion, and have a zero direct greenhouse gas emission. However, the process used to generate hydrogen in a form useful to power trains does produce a small amount of greenhouse gases. By using wind energy and electrolysis, 6.85 grams of greenhouse gases per MJ of LHV are produced, which is an insignificant amount compared to the 22 pounds of greenhouse gas emissions from one gallon of gasoline. Trains are prime targets for hydrogen propulsion due to their ability to store massive tanks of hydrogen.

Emissions comparison

Rail transportation emits about 0.2 pounds of greenhouse gases per passenger mile () when each car is filled with 50 passengers. This figure increases to about 0.5 pounds per passenger mile (140 g/km) when only filled with half that amount. These numbers are still much lower than those of jet transportation, about 1 pound per passenger mile (280 g/km), and that of a solo car driver, about 1.15 pounds per passenger mile (325 g/km). Even the fuel efficient

Prius The is a Compact car, compact/small family car, small family liftback (supermini/subcompact sedan (car), sedan until 2003) produced by Toyota. The Prius has a Hybrid vehicle drivetrain, hybrid drivetrain, combined with an internal combustion ...

emits more greenhouse gases per passenger mile. Estimates have shown that if just 10% of long-distance freight that is currently moving by truck were to be moved instead by diesel trains, the resulting carbon emission reduction would be the equivalent of taking 2 million cars off the road. The results are more dramatic when the diesel train figures are replaced by hybrid and electric train figures.

References

External links

* * * {{DEFAULTSORT:Environmental Design In Rail Transportation Rail technologies Sustainable transport