Since they require plenty of water to be circulated in this cycle, coal power plants need to be located near a body of water.
The process of coal fired plants can be seen below in Figure 3. Coal power plants have many associated environmental impacts on the local ecosystem.
The burning of coal releases many pollutants - oxides of nitrogen NOx and sulfur SOx - and particulate matter. They also emit greenhouse gases , such as carbon dioxide CO 2 and methane CH 4 , which are known to contribute to global warming and climate change.
To help stunt the emission of these, power plants require technology to reduce the output of these harmful molecules. Large quantities of water are often needed to remove impurities from coal, [10] this process is known as coal washing. For instance, in China, around one-fifth of the water used in the coal industry is used for this process. This results in less sulfur dioxide SOx being produced, along with less carbon dioxide CO 2 due to higher thermal efficiencies.
When power plants remove water from the environment , fish and other aquatic life can be affected, along with animals relying on these sources. The discharge of water from the power plants and coal washing requires monitoring and regulation.
The map below shows which primary energy different countries get the energy to generate their electricity from. Grinding the coal into powder increases its surface area, which helps it to burn faster and hotter, producing as much heat and as little waste as possible.
As well as heat, burning coal produces ash and exhaust gases. The ash falls to the bottom of the boiler and is removed by the ash systems 3. It is usually then sold to the building industry and used as an ingredient in various building materials, like concrete. The gases enter the exhaust stack 4 , which contains equipment that filters out any dust and ash, before venting into the atmosphere.
The exhaust stacks of coal power stations are built tall so that the exhaust plume 5 can disperse before it touches the ground. This ensures that it does not affect the quality of the air around the station. Burning the coal heats water in pipes coiled around the boiler, turning it into steam. The hot steam expands in the pipes, so when it emerges it is under high pressure. The pressure drives the steam over the blades of the steam turbine 6 , causing it to spin, converting the heat energy released in the boiler into mechanical energy.
A shaft connects the steam turbine to the turbine generator 7 , so when the turbine spins, so does the generator. The generator uses an electromagnetic field to convert this mechanical energy into electrical energy. After passing through the turbine, the steam comes into contact with pipes full of cold water. In coastal stations this water is pumped straight from the sea 8. The cold pipes cool the steam so that it condenses back into water. It is then piped back to the boiler, where it can be heated up again, turn into steam again, and keep the turbine turning.
Finally, a transformer converts the electrical energy from the generator to a high voltage. The national grid uses high voltages to transmit electricity efficiently through the power lines 9 to the homes and businesses that need it Here, other transformers reduce the voltage back down to a usable level.
Coal is a finite fossil fuel, although it will not run out until the s at current usage rates. But the UK's climate change commitments mean it cannot build more coal plants without technology to reduce their carbon emissions. To address that challenge, the UK is diversifying its energy mix with other energy sources to be less reliant on coal for electricity.
The UK relies on coal-fired power stations to generate consistent levels of electricity. But the Government's climate change commitments mean no more coal-fired plants will be built until the technology is available to bring down their carbon emissions.
By the cost of generating electricity using coal with carbon capture and storage CCS technology to reduce emissions should be about CCS is coal's biggest affordability challenge but the technology should get cheaper as more plants are built.
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Smart Export Guarantee. Insulation advice. Energywise blog. Its chimney is metres tall. Plant Bowen is one of the largest coal-fired power plants in the United States.
Plant Bowen uses recirculating cooling, decreasing the amount of water that must be withdrawn. Skip to main content. Search Search. Water Science School. Get water-use data. Water Use Information by Topic Learn more. Science Center Objects Overview Related Science Publications Multimedia Much of the electricity produced in the United States and the world comes from the burning of fossil fuels, such as coal.
Below are other science topics associated with thermoelectric power and water use. Date published: August 30, Filter Total Items: 1. Year Select Year Apply Filter. Date published: June 18, Below are publications associated with thermoelectric power and water use. Dieter, Cheryl A. Attribution: Maryland-Delaware-D. View Citation. Dieter, C. Maupin, Molly A. Maupin, M.
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