Coal is a solid fossil fuel with global reserves of over 100 years. Coal was the original fuel of the industrial revolution and continues to be a key energy source. It currently provides 30.3% of global primary energy needs and is used to generate 42% of worldwide electricity.
Current use of coal
World
Globally, in 2011 coal was the fastest growing form of energy outside renewables. Coal is mined in over 100 countries, across all continents except Antarctica. It is a widely available and affordable fuel. The largest reserves are found in the USA, Russia, China, India and Australia. Further data and statistics can be found on the World Coal Association website.
UK
Coal consumption in the UK has fallen since the 1980s (see figure 2) as the UK has been able to develop its North Sea oil and gas fields and complete a substantial nuclear electricity programme. Today the UK imports over 50% of the coal it uses - the main sources being Russia, South Africa, Indonesia, Australia and Columbia. The UK total consumption is about 1% of global coal use.
In 2010 the UK produced 18.4 million tonnes, imported 26.5 million tonnes and consumed 51.5 million tonnes, with the balance of 6.6 million tonnes being lifted from coal stocks. Electricity generation accounted for 80% of consumption, with coal providing 28% of total supply. Although this level of consumption is about half the UK peak in the 1980’s, it is still one of the main sources of energy for the UK. More information on UK coal production and consumption can be found on the UK Coal website, the Confederation of United Kingdom Coal Producers website and the Association of UK Coal Importers website.
Challenges to the future use of coal
Climate change
Burning of fossil fuels produces carbon dioxide and other gases that contribute to the greenhouse effect. Coal combustion for electricity generation has about twice the carbon dioxide emissions of gas per unit generated. In 2009, 43% of CO2 emissions from fuel combustion were produced from coal. In the longer term it will not be possible to deliver targets and programmes to reduce greenhouse gas emissions and continue to burn coal at current levels.
One potential solution to this challenge is the installation of carbon capture and storage technology which removes the carbon dioxide from the combustion emissions for permanent disposal underground. All of the several candidate techniques are at early stages of development and a wide range of R&D and pilot projects are underway worldwide. However, it is not yet clear whether this technology can be commercially viable.
Acid gas emissions
In addition to greenhouse gases, during the combustion process coal fired power stations emit oxides of sulphur (SOx) and oxides of nitrogen (NOx). These gases mix with water vapour and other substances in the atmosphere to form acid rain. This problem can be reduced through the use of low sulphur coal, the use of low NOx combustion technology and the introduction of flue cleaning technology.
Future use of coal
World
Over the next twenty years world-wide energy demand is widely forecast to increase by over 40% with much of this increase in the developing world. The abundance of coal worldwide makes it a readily available source of heat energy for these countries. Even without carbon capture technology, coal use is therefore likely to grow substantially in the medium term. Unless carbon capture and storage technology can be developed to a commercial stage, this continued expansion of coal will present a major challenge to greenhouse gas emission reductions. The coal industry recognises this challenge and considerable work is underway to develop solutions. Further details can be found on the ICE Briefing Sheet on Carbon Capture and Storage.
UK
Electricity generation from coal is projected to decrease in the UK over the next 20 years. The 2011 UK government central scenario projects a reduction in annual coal generation from the current 100 TWrs to around 60 TWhrs in 2020 and 15 TWhrs in 2030. This is largely the result of UK and EU climate change policies and by 2030 all coal generation is expected to be fitted with CCS.
However, during these 20 years coal will play a key role in maintaining security of supply during the transition to a low carbon electricity supply. UK coal stations are very flexible in their output. As the amount of wind generation on the system increases, the available supply is likely to become much more variable due to fluctuations in wind speeds. Coal stations can provide reserve capacity to fill in during low wind speed periods.