From Envirowiki

Coal is a fossil fuel mined from the earth for consumption in power plants for the generation of energy. It is most often converted to electricity by way of burning the coal which produces heat. Water can be heated at this point, creating steam which generates electricity through causing the movement of turbines. In general, coal is seen as a highly polluting form of energy generation, as it emits copious amounts of carbon dioxide and many other pollutants such as carbon monoxide and sulfur dioxide, depending on the chemical composition of the coal involved.

[edit] Flavours

Coal comes in a few different flavours, none of which taste any good.

• Black coal, or anthracite - the most carbon-pure, and economically valuable coal. This coal has been in the ground under serious pressure for the longest time.
• Bituminous coal, and sub-bituminous coal.
• Brown coal - Also known as lignite, usually has a high sulphur content. The most polluting coal per megawatt of energy produced. Hazelwood power station in Victoria burns brown coal at the source, and is the developed world's most polluting powerstation^{[reference needed]}.

[edit] Consequences

The obvious first consequence of coal use is vast amounts of cheap energy (although definitely not infinite, see #Coal reserves below.). This now appears to be offset by the massive amount of negative impacts from the practice.

[edit] of Burning Coal

• the Carbon dioxide added to the atmosphere though coal burning adds to the Greenhouse Effect, increasing the impact of Global Warming or Climate Change
• Acid Rain: sulphur and other elements combine during combustion (an exo-thermic chemical reaction) producing new compounds. These compounds can have extra hydrogen atoms making them acidic. Acid rain can kill plants, erode rock and poison water.
• Smoke and smog: The obvious visual effect of burning. Coal fired power stations in Australia are fitted with scrubbers which filter most of the particles from the gaseous waste.
• Aromatic Coal Tars: Burning coal produces a wide variety of organic chemicals which include esthers. Like benzene, these organic chemicals cause cancer. Old city gas works and blast furnaces for the production of steel are highly contaminated with aromatic coal tars and are unfit for agriculture or domestic habitation. The organic chemicals found in coal tar find their way into the water table making ground water poisonous and carcinogenic.

[edit] of Mining Coal

Coal mining is undertaken by two broad methods. Undergound: involves tunnelling to the coal seam and extracting the coal back out the tunnel. Longwall mining is a method of underground coal mining.

Open Cut mining: All the top soil and rock above the coal seam is quarried out making a hole. The coal seam is exposed at the bottom of the hole, blasted and transported out with massive earth moving equipment.

• The local environment surrounding the sites where coal mining has occurred takes many years to regenerate back to a normal state. Both physical disruption and chemical contamination from coal mining inhibit the reclamation of the land by its natural species.
• Open cut coal mines produce dust and noise. The dust is detrimental to agricultural production downwind of the mine. Vineyard owners in the Hunter Valley, Australia have raised objections to new open cut mines being developed near their vineyards^{[reference needed]}.
• Transporting coal via road causes noise, strong vibration, coal dust and degrades the road due to heavy axle loads. Residents along a coal haulage route complain because of these negative consequences.
• Mine Subsidence: Underground coal mines do not replace the coal they extract with another material that will support the roof of the cavity they create. Typically the roof is allowed to cave behind the machines performing the extraction. The caving in of the mine roof can cause structural damage to roads and buildings above the mine.
• Earthquakes: Changing the mass of material pressing on the layers of rock underneath can cause movement. Seismic activity is increased as the geological structures adjust to changed forces. Coal mining was a significant contributing factor of the Newcastle earthquake of 1989^[1][2][3][4]
• Leaching of contaminants such as sulfuric acid can lead to the pollution of groundwater and deaths of exposed plants and animals.
• Both the mining of coal and the deserted mine release methane, which is another culprit in global climate change.
• Mining coal can result in the polluting of surrounding area with radioactive contaminants.

[edit] Carbon Capture and Storage

Main article: Carbon capture and storage

Carbon Capture and Storage are a number of technologies aimed at taking the carbon dioxide output of coal-fired power production, and burying it in secure sites. It has a number of problems.

[edit] Coal reserves

The Energy Watch Group have predicted that global coal production will peak at around 2025^[5].

[edit] Economics

Coal extraction is an extremely profitable undertaking (high gain for low input^{[reference needed]}), and has a reasonably safe marketplace, due to the huge demand for coal worldwide.

Coal currently sells for around US$50/tonne (AU$80). current prices can be tracked at http://www.globalcoal.com/

Royalty rates in Australia vary depending on the method of extraction. Open cut is 7% of the value of the coal^[6], making it worth a little over $3.50/tonne at current rates.

[edit] Coal Use

[edit] United States

Coal use remains a primary source of energy in the United States, accounting for over half of the nation’s annual generation of power. Many believe that coal will play an increasingly larger role in the American energy sector as the United States has vast coal reserves within its borders and such utilization will allow greater energy independence. Relative to other forms of energy generation, its pricing will be rather stable. In that the U.S. will have to rely less upon imported energy, they will eliminate many of the political and security related concerns regarding the importation of energy, especially from countries with which they may have tenuous relationships^[7].

Utility companies may lean toward a greater reliance on coal because they have a greater degree of familiarity and may be more comfortable with the status quo regarding its usage.

The lack of stringent regulations on the types of coal-fired power plants will most likely lead to the construction of more conventional power plants, as there aren’t enough incentives for utilities to focus on building more modern (more expensive) sites.

The more emissions standards go up in the United States, the more our relationship with coal is going to have to change. The U.S. will either have to reduce its use within our national energy portfolio, or will have to find and implement cleaner ways of consuming coal.

Unless the United States goes through a major shift in its attitude toward nuclear power, its support of renewable energy, or in its energy consumption patterns, coal will become an even greater part of the energy sector^[7].

[edit] China

China is poised to become an enormous consumer of coal within the coming decades, as their growing population and economy require progressively greater amounts of energy inputs. The nation has plans to install many more coal power plants to exploit the vast resources of coal within their borders to meet this growing need. As it is, coal is one of the main, if not primary, source of energy for the Chinese, and the current movement toward greater coal use within China has been an issue of much concern for environmentalists. Furthermore, the impacts on public health in China are a subject of discussion and concern.

the volume of Chinese Coal use is often used as a way to excuse Australia's emissions - i.e. "if we stop emitting, china will make it worse anyway"

[edit] Sources

1. ↑ Human-Made Earth Quakes - a Serious Geo-Economic Factor, Christian Klose, Columbia University
2. ↑ Mining triggered Newcastle quake, says US academic, ABC News Online, Tuesday, January 9, 2007. 10:08am (AEDT)
3. ↑ Coal Mining Causing Earthquakes, Study Says, Richard A. Lovett, National Geographic News, January 3, 2007
4. ↑ Coalmining set off Newcastle earthquake: researchers, Wendy Frew, January 9, 2007, Sydney Morning Herald
5. ↑ Zitte, Dr. Werner; Jörg Schindler (2007-07-10) Coal: Resources and Future Production . Ottobrunn: Energy Watch Group, 47. Report. Retrieved on 2008-06-26.
6. ↑ http://www.dpi.nsw.gov.au/minerals/resources/royalty/royalty-rates
7. ↑ ^{7.0 7.1} Fields, S: "Coal: Poised for a Comeback?", page 890. Environmental Health Perspectives, 2004