Keywords

Coal-fired power generation; steam turbine; coal mining; global electricity production from coal; national electricity production from coal; history of coal-fired power generation

The History of Coal-Fired Power Generation

The earliest established regular use of coal was around 2000 BC in northern and western China, in the region which today covers the Inner Mongolia autonomous region and the province of Shanxi. At that time wood was the fuel most commonly used for heating and cooking in most parts of the world but the availability of wood was scant in this Chinese region while coal was available close to or at the earth’s surface.¹ This pattern has been copied in other parts of the world in later eras, with coal used when wood has become scarce. The use of coal in metallurgical processes and metalworking appeared much later. Greek literature cites the use of coal in metalworking at around 300 BC, the first extant reference.

While coal has been used sporadically since those times in many parts of the world, the roots of modern coal use are found in Britain, a country which has a long history of coal exploitation. Coal was mined in Britain by the Romans 2000 years ago. This coal was transported as far afield as the Rhineland where bituminous coal was traded for use in the smelting of iron ore. Coal extraction fell off after Roman influence declined during the fourth century AD and was only revived on any significant scale in the twelfth century. The fuel was used mainly for heating and cooking, replacing wood which was becoming scarce. Metalworking craftsmen, or artificers as they were then known, also took up the use of coal because it burned more hotly than wood or charcoal.

Small-scale use of coal continued into the eighteenth century when the Industrial Revolution stimulated the widespread use of coal both for industrial processes and as a fuel to drive steam engines of various types. Surface mining initially provided most coal but as the eighteenth century progressed, deep mining began to develop. Mining also developed in Germany and Poland during the eighteenth century, and to a small extent in India – then part of the British Empire – but it was not until the nineteenth century that it became widespread elsewhere. At the turn of the twentieth century Britain was still the second-largest coal producer in the world, its production exceeded only by the USA. Ironically Britain, which still has major coal reserves, is now a large importer of coal.

The use of coal for power generation began in the USA in the 1880s, based on the same technology that was then used to create mechanical power, the steam engine. Coal was burned to raise steam and the steam used to drive an engine, which in turn drove a dynamo or alternator which produced electricity. The first fully commercial electric power station was the Pearl Street station in New York which was built by Thomas Edison and started operating in 1882. (An earlier test station was built by Edison at Holborn Viaduct, London, in early 1882 but this station only ran for a few months to prove the technology.) The Pearl Street plant used a Porter Allen reciprocating steam engine and dynamo to produce a direct current which supplied power for lighting. Output was around 130 kW.

The next major advance was the steam turbine which was invented by Charles Parsons in 1884. Steam turbines allowed more efficient energy conversion and higher outputs. By 1900 steam turbines could produce 1200 kW and by 1910 individual units could generate 30,000 kW. These large steam turbines provided the technology on which many of the power stations in the developed world relied (alongside hydropower) and during the twentieth century coal-fired power stations using steam turbines became the most important source of electricity across the globe. They remain the single most important source of electricity in the second decade of the twenty-first century.

Global Electricity Production from Coal

The amount of electricity generated from coal has increased continuously since the beginning of the twentieth century. Early global figures are difficult to find but, in 1949, UN statistics indicate that 531 TWh of electric power was generated from thermal power stations; the majority of these would have been based on coal combustion along with some oil (gas was not yet widely used for power generation). Total global production of electricity in 1949, based on UN data, was 840 TWh, with thermal power plants responsible for 63% of the total, and hydropower stations for most of the remainder.²

By 1973 total annual global production had risen to 6117 TWh of which 2343 TWh or 38% was produced from coal and peat. These figures can be found in Table 1.1 which also shows the global production of electricity from coal between 2004 and 2012, based on data from the International Energy Agency. Electricity production from coal in 2004 was 6994 TWh, more than the total global electricity production in 1973, and this production accounted for 39.8% of global output. Production from coal rose virtually continuously between 2004 and 2012 (the exception being 2009 during the global crisis) so that for 2012 total production of electricity from coal was 9169 TWh, 40.4% of all the electricity produced across the world.

The use of coal for power production is greatest in countries which have large reserves of the fuel. The national league tables are dominated by China and the USA. Table 1.2 contains figures for the top 10 countries listed by the volume of coal-based electricity each generated in 2012. At the top of the table is China which generated 3785 TWh from coal that year, followed by the USA with 1643 TWh and India with 801 TWh. The leading European nations were Germany which derived 287 TWh from coal and the UK with 144 TWh. It is notable that Japan and South Korea, countries that have limited coal reserves themselves, are also big producers of electricity from coal. Both must import the coal they burn.

Many of the countries in Table 1.2 have a mixture of generation types, but some rely heavily on coal for their electric power. This is illustrated in Table 1.3 which shows the 12 countries that relied the most heavily on coal for their electric power in 2012. Top of the list is Mongolia which derived 95% of its electric power from coal, followed closely by South Africa with 93%. Both have extensive indigenous supplies of coal. Poland with 83% is the next nation on the list. This European country has significant lignite reserves which is uses to produce its electricity. Two of the three biggest coal energy exploiters, China (81%) and India (71%), are fourth and fifth in the table by this measure. However, the third largest exploiter, the USA, is only eleventh in the table. The USA derives 38% of its power from coal and the remainder from a mixture of other sources. Of the other countries in the list, Australia and India have extensive coal reserves. However Israel, Germany, the UK, and Japan are all importers of coal for power generation.