Coal-fired power stationA coal-fired power station or coal power plant is a thermal power station which burns coal to generate electricity. Worldwide there are over 2,400 coal-fired power stations, totaling over 2,000 gigawatts capacity. They generate about a third of the world's electricity, but cause many illnesses and the most early deaths, mainly from air pollution. A coal-fired power station is a type of fossil fuel power station. The coal is usually pulverized and then burned in a pulverized coal-fired boiler.
CoalCoal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is a type of fossil fuel, formed when dead plant matter decays into peat and is converted into coal by the heat and pressure of deep burial over millions of years. Vast deposits of coal originate in former wetlands called coal forests that covered much of the Earth's tropical land areas during the late Carboniferous (Pennsylvanian) and Permian times.
Coal in ChinaChina is the largest producer and consumer of coal and the largest user of coal-generated electricity in the world. The share of coal in the Chinese energy mix declined to 55% in 2021 according to the US Energy Information Agency. The Chinese central government has clamped down on the pace of new construction of coal plants and shifted to renewable, nuclear and natural gas sources. At the same time, coal consumption reached new heights in China with carbon dioxide emissions from coal-fired electricity production estimated to top 4.
Coal phase-outCoal phase-out is an environmental policy intended to stop using the combustion of coal in coal-burning power plants, and is part of fossil fuel phase-out. Coal is the most carbon-intensive fossil fuel, therefore phasing it out is critical to limiting climate change and keeping global warming to 1.5 °C as laid out in the Paris Climate Agreement. The International Energy Agency (IEA) estimates that coal is responsible for over 30% of the global average temperature increase above pre-industrial levels.
Coal-seam fireA coal-seam fire is a burning of an outcrop or underground coal seam. Most coal-seam fires exhibit smouldering combustion, particularly underground coal-seam fires, because of limited atmospheric oxygen availability. Coal-seam fire instances on Earth date back several million years. Due to thermal insulation and the avoidance of rain/snow extinguishment by the crust, underground coal-seam fires are the most persistent fires on Earth and can burn for thousands of years, like Burning Mountain in Australia.
Health and environmental impact of the coal industryThe health and environmental impact of the coal industry includes issues such as land use, waste management, water and air pollution, caused by the coal mining, processing and the use of its products. In addition to atmospheric pollution, coal burning produces hundreds of millions of tons of solid waste products annually, including fly ash, bottom ash, and flue-gas desulfurization sludge, that contain mercury, uranium, thorium, arsenic, and other heavy metals.
Coal in AustraliaCoal is mined in every state of Australia. The largest black coal resources occur in Queensland and New South Wales. About 70% of coal mined in Australia is exported, mostly to eastern Asia, and of the balance most is used in electricity generation. In 2019-20 Australia exported 390 Mt of coal (177 Mt metallurgical coal and 213 Mt thermal coal) and was the world's largest exporter of metallurgical coal and second largest exporter of thermal coal. Coal mining in Australia has been criticized, due to carbon dioxide emissions during combustion.
Renewable energyRenewable energy is energy from renewable resources that are naturally replenished on a human timescale. Renewable resources include sunlight, wind, the movement of water, and geothermal heat. Although most renewable energy sources are sustainable, some are not. For example, some biomass sources are considered unsustainable at current rates of exploitation. Renewable energy is often used for electricity generation, heating and cooling.
Renewable energy commercializationRenewable energy commercialization involves the deployment of three generations of renewable energy technologies dating back more than 100 years. First-generation technologies, which are already mature and economically competitive, include biomass, hydroelectricity, geothermal power and heat. Second-generation technologies are market-ready and are being deployed at the present time; they include solar heating, photovoltaics, wind power, solar thermal power stations, and modern forms of bioenergy.
Phase transitionIn chemistry, thermodynamics, and other related fields, a phase transition (or phase change) is the physical process of transition between one state of a medium and another. Commonly the term is used to refer to changes among the basic states of matter: solid, liquid, and gas, and in rare cases, plasma. A phase of a thermodynamic system and the states of matter have uniform physical properties. During a phase transition of a given medium, certain properties of the medium change as a result of the change of external conditions, such as temperature or pressure.
