Sign up to access the complete lesson and track your progress!
Unlock This CourseCoal is one of the world's most important fossil fuels and has powered human civilisation for centuries. It's a black or brown sedimentary rock that burns to release energy, making it crucial for electricity generation and industrial processes. As a non-renewable resource, coal takes millions of years to form but can be consumed quickly, making it unsustainable in the long term.
Key Definitions:
Coal forms through a process called carbonisation. Dead plant material in swamps gets buried under layers of sediment. Over millions of years, heat and pressure transform this organic matter into coal. The longer the process, the higher the carbon content and energy value.
Not all coal is the same. Different types have formed under varying conditions, resulting in different energy contents and uses. Understanding these differences is crucial for energy planning and environmental considerations.
Lowest grade coal with 25-35% carbon content. High moisture content makes it less efficient. Mainly used in power stations near mining sites due to transport costs.
Medium grade with 45-86% carbon content. Most commonly used type globally. Good for electricity generation and steel production. Burns hotter than lignite.
Highest grade with 86-97% carbon content. Burns cleanest and hottest. Rare and expensive. Used for heating homes and specialist industrial processes.
Coal extraction depends on how deep the coal seams are buried. Each method has different costs, environmental impacts and safety considerations that affect energy security planning.
When coal seams are close to the surface (less than 60 metres deep), surface mining is used. This includes strip mining and mountaintop removal. It's cheaper and safer than underground mining but causes significant landscape disruption.
Lower costs, higher recovery rates (up to 90%), safer working conditions and faster extraction. Equipment can be larger and more efficient.
For deeper coal seams, underground mining is necessary. Miners use shafts and tunnels to reach coal deposits. Two main methods are room-and-pillar mining and longwall mining.
Higher costs, safety risks from cave-ins and gas explosions, lower recovery rates (50-60%) and health risks from coal dust exposure causing pneumoconiosis.
Coal use creates significant environmental challenges that affect energy security decisions. These impacts occur during extraction, transport and combustion phases.
Coal burning releases CO2, SO2 and particulates. Creates acid rain and contributes to climate change. Coal accounts for 30% of global CO2 emissions.
Mining contaminates groundwater with heavy metals. Coal washing produces toxic slurry. Power plants use huge amounts of water for cooling.
Surface mining destroys ecosystems and landscapes. Subsidence from underground mining damages buildings and infrastructure above.
China is the world's largest coal producer and consumer, accounting for over 50% of global coal use. Coal provides about 60% of China's electricity despite massive renewable energy investments. The country faces severe air pollution problems, with cities like Beijing experiencing dangerous smog levels. China is trying to reduce coal dependence through renewable energy expansion and cleaner coal technologies, but economic growth demands make this transition challenging. The government has closed thousands of small, inefficient coal mines whilst investing in cleaner, larger facilities.
Coal remains economically vital for many countries, providing jobs, export income and affordable electricity. However, economic benefits must be weighed against environmental and health costs.
Major coal exporters include Australia, Indonesia and Russia, whilst importers include Japan, India and South Korea. Coal trade affects international relations and energy security strategies.
Coal mining provides direct employment for millions globally. It supports related industries like transport and steel production. Coal is often cheaper than alternatives, keeping electricity costs low for consumers and industry.
The UK was once heavily dependent on coal, with mining employing over one million people in the 1920s. However, cheaper imports, environmental concerns and government policy led to massive industry decline. The last deep coal mine closed in 2015, ending centuries of coal mining tradition. The UK now imports most coal needs whilst transitioning to renewable energy. This shows how countries can reduce coal dependence, though it requires significant economic and social adjustment for affected communities.
Coal presents both opportunities and challenges for energy security. Whilst it provides reliable baseload power, environmental concerns and finite reserves create long-term sustainability issues.
Coal provides reliable, continuous power generation. Large global reserves ensure supply security. Existing infrastructure makes it cost-effective. Coal plants can quickly adjust output to meet demand changes.
Finite reserves mean eventual depletion. Environmental regulations increase costs. Climate change commitments require reduced coal use. Public health concerns create political pressure for alternatives.
Coal's future role in energy security depends on technological developments, environmental policies and economic factors. Clean coal technologies and carbon capture might extend coal's viability, but renewable energy growth challenges its dominance.
Technologies like carbon capture and storage (CCS) could reduce coal's environmental impact. However, these remain expensive and unproven at large scale. High-efficiency, low-emission (HELE) coal plants can reduce emissions but don't eliminate them.
Moving away from coal requires massive investment in alternatives and grid infrastructure. Coal-dependent regions face economic disruption and job losses. Developing countries argue they need affordable coal for economic development, creating global policy tensions.