The upsurge in atmospheric carbon dates back to the Industrial Revolution, when people first started to burn fossil fuels – mostly coal – to produce energy.
Coal is the most carbon-intensive fossil fuel, and is therefore a leading source of carbon dioxide emissions and can be a contributor to local air pollution. The carbon footprint of a coal station is about 880 grams of carbon dioxide per kWh.
According to the World Energy Outlook 2014, the International Energy Agency (IEA) predicts that coal’s share of the electricity generation worldwide will fall from 41% in 2012 to 31% by 2040.
There is great pressure on electricity generating companies to burn coal in ways that cause fewer emissions. For example, Carbon Capture and Storage (CCS) technology seeks to capture CO2 before it is released into the atmosphere and store it underground.
The UK Government believes that CCS is important to tackling global climate change, and has ruled that no new coal-fired power stations will be built without it. Some types of CCS can be retrofitted to existing coal-fired power stations, but only if there is enough space on the site for the new equipment. Adding CCS to coal-fired power stations – whether retrofitted or new build – will inevitably increase costs.
In April 2012, the UK government opened a £1 billion capital funding ‘Commercialisation competition’ to support the development of CCS. In December 2013 and February 2014, two projects were awarded multi-million pound contracts to undertake Front End Engineering and Design (FEED) studies. One of these projects is a new super-efficient coal-fired power station (the White Rose project), while the other project is for a new CCGT fitted with CCS technology. It is hoped that the FEED programme will help enable the projects to proceed to a construction phase. The Department of Energy and Climate Change hope that through this work and other developments, CCS will be cost competitive in the 2020s.
Carbon dioxide has already been stored underground in many locations around the world. Since 1996, Norway has safely stored CO2 in a saline aquifer above the Sleipner gas field in the North Sea, with no signs of leakage – and continues to store CO2 at up to 1 million tonnes each year. If the technology proves successful, CCS coal-fired power plants will play an important part in the future UK energy mix.