From a Lump of Coal to a Jolt of Electricity Quiz

Answer: At least 50%

The Carboniferous Period lasted from about 359 to 299 million years ago.

Coal is not homogeneous - it has no chemical formula per se. Coal was formed where plants grew. As they died they fell into swamp water. As new plants grew, some died and they too fell into the swamp waters. This cycle was repeated many times. The surface of the earth changed bringing dirt, rock and water. After millions of years many layers had formed. The weight, heat and pressure produced chemical and physical changes leaving rich carbon deposits, which became coal.

Coal is defined as a "readily combustible rock containing more than 50% by weight of carbon". Coal also contains hydrogen, oxygen, nitrogen, ash and sulfur.

Answer: Peat

Peat is accumulation of partially decayed vegetation or organic matter found in bogs or mires, which, when collected and water extracted, makes a form of non-renewable fuel. It is an important source of fuel in Ireland, Finland and Russia.

Lignite is brown coal, which is of a low thermal quality, compared with black coal, largely because of a higher water content.

Of higher quality is black coal. Bituminous coal contains tar-like substance called bitumen or asphalt and as such has a soft feel.

Anthracite is a harder, compact type of coal that has a glossy look. This type of coal has the highest carbon concentration and the fewest impurities which makes it the most efficient coal.

In Australia, where I live, coal is used for domestic power generation or is exported. Australia is the fourth highest producer of coal and is the largest exporter. Australia's coal is much in demand as nearly all exported coal is anthracite.

Answer: To blast the rock above the coal out of the way

Australia mines over 80% of its coal by open cut, while in the USA it is 65% and globally 40%. In open cut mining, the coal seams are closer to the surface than in underground mining but they are still covered by layers of rock and dirt. This is all blasted by explosives. Massive cranes, called drag-lines, then scoop away the rock and dirt until the coal seam is exposed.

The coal is then drilled and fractured and carted by huge trucks (which can carry up to 220 tonnes of coal per load) to the rail head where it is transported to the power stations or to port for export.

Answer: Water is the source of steam needed to generate electricity

To generate electricity in a thermal power station, steam is needed. Coal is the fuel needed to heat the water to form steam. This is the most common world-wide method of creating heat in a power station. Other methods used to convert water into steam are nuclear fission, oil or natural gas.

Answer: Steel manufacture

Metallurgical coal, or coking coal, is used to make coke which is needed for iron and steel-making. Coke is made by heating bituminous coal to very high temperatures in the absence of air to form a porous, hard black rock of concentrated carbon. Major producers are Australia, Canada and United States, all of which are major exporters, mainly to China and Japan.

The demand for this type of coal is correlated with the demand for steel. In the early 2000s the demand for steel by the newly industrialised China made coking coal prices rise enormously but China's steel production fell in the second decade of the 21st century and prices normalised.

Answer: True

For electricity to be generated in a thermal power station, a turbine is turned by steam produced by coal heated water.

Electric generation occurs when kinetic energy transforms into electricity. This is based on Faraday's Law. It occurs by rotating a magnet within "closed loops of a conducting material" usually copper wire. Almost all commercial electricity is manufactured using electromagnetic induction. A turbine is connected to a generator, which is a series of coils of wire that are spun very quickly around a set of magnets. The moving magnets cause electrons in the metal wires (copper wire is preferred) to move from one location to another, creating an electrical current which is what electricity actually is.

Other ways of generating electricity are by:
1. Electochemistry which is direct transformation of chemical energy into electricity. This is how batteries are manufactured
2. The photovoltaic effect which is the transformation of light into electrical energy. This is what occurs in solar cells and panels.

Besides coal, steam turbines can be rotated by heating natural gas or oil, or by water. This is what occurs in hydroelectricity plants where rushing water is fast enough to drive the turbines at the required speed. Turbines can also be generated by heat that occurs during nuclear fission.

Answer: It is condensed into water to be reused

In the electricity generation process, the heat from the steam is reduced in temperature but it is still much hotter than the atmosphere. Traditionally, the water was placed in cooling towers. In more efficient plants, for this heat to dissipate, it enters a condenser which is cooled by water from the external water source and the low temperature steam is condensed into water. Some plants have multiple turbines, arranged in series, to try to extract as much power out of the steam-water cycle as possible.

The water is then able to be recycled into the the coal-fired steam production process.

Answer: True

Electrical energy must be generated at the same rate at which it is consumed, as large scale electricity cannot be stored as in a battery. This is why there are blackouts in times of high electricity demand: the power stations cannot keep up with demand.

Electric power transmission is bulk movement of electricity from a power plant to an electrical substation, where it is then distributed to consumers. Power travels along aluminium wires at around 110kV. When it arrives at the substation, the sub-station acts as a step-down transformer to convert the high voltage into household and commercial voltage of 110-240volts.

Answer: Coal

Surface mining of coal disrupts or destroys existing vegetation and wildlife and their collective habitats. Mine tailings (dumps) can produce acid mine drainage which works its way into waterways.

All coal seams contain a mix of carbon dioxide (CO2) and methane (CH4). These gases are released when the coal is mined, and this release is referred to as fugitive emissions.

Fossil fuels release carbon dioxide when they burn, such as in electricity generation. This contributes to the greenhouse effect and consequently increases global warming. Of the three fossil fuels used in making electricity, coal, oil, natural gas, for a given amount of energy released, coal produces the most carbon dioxide and natural gas produces the least.

Nuclear fission, is a non-renewable energy resource, but does not generate carbon dioxide. It has, obviously other risks.

Solar power is inefficient - it is by its very nature a photovoltaic effect - and expensive technology.

Wind power is renewable and is efficient as it turns a turbine directly. However its product is variable due to its source. Steps are needed to ensure this variability has offset mechanisms to be a viable source of fuel for electricity generation.

Answer: Introduction of clean coal technology

"Clean Coal" is a public relations name for coal pollution mitigation. While there have been reasonable attempts to significantly reduce the sulfur content of power plant emissions, the overwhelming focus is now on reducing CO2 emissions.

There is considerable demand in the community to stop coal-fired electricity and swap over to renewable fuel sources. Issues that arise out of this approach include effectiveness, efficiency, pollution technology costs and variability of supply. Coal is going to be around for a few more decades until renewable energy sources can match coal in its effectiveness and cost. Hence the industry is concentrating on literally 'cleaning up its act'. Carbon capture and sequestration technology relies on capturing CO2 at some point in the cycle, combining it with other materials to form a solid compound and then burying it to prevent CO2 leaking into the atmosphere.