With all its advantages, coal also has weaknesses. Coal combustion accounts for around 40% of global man-made CO2 emissions. As carbon dioxide is considered responsible for global warming, considerable efforts are undertaken to mitigate or even to completely reduce CO2 emissions. Furthermore, electricity generation from coal can result in emissions of harmful sulphur oxides, nitrogen oxides and particulates.
The challenge of acid rain has been long resolved with the help of technology. A growing number of power plants are designed to combust low-sulphur coals (sulphur content under 1%). Furthermore, sulphur oxides, nitrogen oxides and particulates are to a large extent captured by elaborated filter systems.
The constantly advancing technology is also offering solutions with respect to the carbon dioxide issue, for instance through improved boiler constructions or advanced combustion technologies. An average coal power plant, with an efficiency level of 38%, emits around 2.4 t of CO2 during the combustion of 1 ton of coal. To put it another way, the production of 1MWh of electricity releases 0.9 t of CO2. Therefore, the best way to mitigate carbon dioxide emissions is to improve the efficiency of power plants. For instance, if China were to bring the efficiency of its power plants from an average of 23% to the German average of 42%, 1.1 billion tons or 4% of global CO2 could be saved each year.
Efficiency of Coal Power Plants
Source: Deutsche Bank (2007); Dr. Lars Schernikau “Economics of the International Coal Trade. The Renaissance of Steam Coal”, Springer, 2010.
CCS – Carbon Capture and Storage - technology, which is currently under development, offers a substantial potential to run CO2-free power plants in the future and to use coal in a more environmentally friendly way. There are three main types of processes which can be applied for CO2 capture:
- Flue gas scrubbing – for conventional power plants
- Oxyfuel process
- Integrated Gasification Combined Cycle (IGCC)
Interestingly, the European CO2 emissions trading system, which aims to help the environment, can actually harm it. High CO2 prices are aimed to punish coal, when compared to relatively CO2-friendly natural gas. It may seem reasonable at first glance; however, it brings unintended consequences. While coal-generated electricity gets more expensive, it will be offset by relatively lower coal prices. Thus, under the current system, developing countries which do not take part in the emissions trading system, such as China or India, are provided with incentives to build even more coal power plants. These power plants are fed with even cheaper coal rather than with expensive gas and eventually the CO2 emissions increase.
The environmental protection measures that have been adopted in industrialized countries should also find their way into the environmental policies of developing countries. The extensive experience of developed countries can be used to develop environmentally friendly and sustainable energy policy. However, environmental policies also have to take into account other aspects of human activities and they have to be based on pragmatic, not ideological, foundations.