A coal power plant is a thermal electricity generation facility that operates by burning coal, a carbon-rich fossil fuel, to heat water into high-pressure steam. This steam then turns a turbine connected to an electrical generator, converting the stored chemical energy into electrical energy. Historically, coal has been a dominant global energy source, accounting for approximately half of the United States’ electricity generation throughout the twentieth century. However, this established technology is now recognized for its significant environmental and public health disadvantages.
Atmospheric Emissions and Climate Change
The single largest drawback of coal power involves the massive volume of gaseous pollutants released into the atmosphere during combustion. These emissions fall into two main categories: greenhouse gases, which affect the global climate, and criteria pollutants, which impact local and regional air quality. The burning of coal releases vast amounts of carbon dioxide (\(\text{CO}_2\)), the primary heat-trapping gas responsible for global warming. Coal-fired power stations are considered the largest single contributor to climate change worldwide.
Beyond climate impacts, coal combustion releases pollutants that directly harm human health and the environment, including sulfur dioxide (\(\text{SO}_2\)), nitrogen oxides (\(\text{NO}_{\text{x}}\)), and fine particulate matter (PM). \(\text{SO}_2\) and \(\text{NO}_{\text{x}}\) are precursors to acid rain and ground-level ozone (smog), damaging ecosystems and exacerbating respiratory illnesses. Particulate matter, especially particles smaller than 2.5 micrometers (\(\text{PM}_{2.5}\)), can penetrate deeply into the lungs and bloodstream, leading to asthma, heart problems, and premature death.
Managing Hazardous Solid Waste
A second major disadvantage is the production and disposal of coal combustion residuals (CCRs), commonly known as coal ash. These solid byproducts are generated in enormous quantities, making coal ash one of the largest types of industrial waste in the world. Coal ash is not inert; it contains concentrated trace elements and heavy metals, such as arsenic, lead, mercury, and selenium.
These toxic components do not decompose and pose a long-term contamination risk when the ash is stored. The majority of coal ash is disposed of in large landfills or stored wet in surface impoundments, often unlined ponds near the power plant. Over time, water percolating through these storage sites can leach heavy metals, contaminating local groundwater and surface water supplies. High-profile incidents of impoundment failures have demonstrated the catastrophic environmental damage that can result from the improper management of this toxic solid waste.
Resource Dependency and Infrastructure Scale
The reliance on coal also presents systemic disadvantages tied to the resource itself and the scale of the required infrastructure. Coal is a non-renewable fossil fuel, meaning its supply is finite and extraction causes permanent changes to the landscape. Mining operations, whether surface or underground, can lead to habitat destruction, soil erosion, and the release of methane, a potent greenhouse gas.
Transporting the vast amounts of coal required to fuel power plants necessitates a massive, complex logistical infrastructure involving rail, barges, and trucks. This transportation process itself contributes to air pollution from diesel engines and can cause coal dust to blow off rail cars. Furthermore, the entire system creates long-term economic burdens, as the cost of reclaiming mining sites, treating acidic mine drainage, and perpetually managing the toxic coal ash waste falls on society.