Coal-fired power plant in Dandong, China. Photo: / Max-Leonard von Schaper CC BY-NC

Global coal power emissions mapped

Closing down the 10 per cent most polluting coal-fired plants would reduce air pollution health impacts from coal power generation by nearly two-thirds.

Coal-fired power plants are a major source of both greenhouse gases and toxic air pollutant emissions worldwide. To estimate where action is most urgently required, a Swiss research group at ETH Zurich’s Institute of Environmental Engineering has collected new emissions data and modelled and calculated the undesired side effects of emissions for each of the 7,861 power plant units in the world, including emissions from the supply chain, i.e. mining and transport.

The emissions inventory covers carbon dioxide, methane, particulate matter, sulphur dioxide, nitrogen oxides and mercury. Their health and climate change impacts are quantified, and the technical abatement potential is analysed. The results, which were recently published in the journal Nature Sustainability, show that total greenhouse gas and toxic substance emissions are largest from coal power in China, the United States, India, Germany and Russia.

China, India and the US are the world’s three largest coal consuming and producing countries, and when looking specifically at health impacts, coal power plants in India take the highest toll.

According to the study, Western Europe, North America and China all have more modern power plants, while Eastern Europe, Russia and India still have many older and less efficient power plants with insufficient flue gas treatment, which also often burn coal of inferior quality.

“More than half of the health effects can be traced back to just one tenth of the power plants. These power plants should be upgraded or shut down as quickly as possible,” said Christopher Oberschelp, the lead author of the study. A phasing-out of the ten per cent most polluting plants (by capacity) would reduce coal power greenhouse gas emissions by 16 per cent and human health impacts by 64 per cent.

The global picture of coal power production shows that the gap between privileged and disadvantaged regions is widening. The scientists say that this is happening for two reasons.

Firstly, wealthy countries – such as in Europe – import high-quality coal with a high calorific value and lower emissions of harmful air pollutants. The poorer coal-exporting countries (such as Indonesia, Colombia and South Africa) are left with low-quality coal, which they often burn in outdated power plants without modern flue gas treatment.

Secondly, “In Europe, we contribute to global warming with our own power plants, which has a global impact. However, the local health damage caused by particulate matter, sulphur dioxide and nitrogen oxides occurs mainly in Asia, where coal power is used to manufacture a large proportion of our consumer products,” said Oberschelp.

Global coal resources will last for several hundred years, so the harmful emissions need to be limited politically. Reducing the negative health and environmental effects of coal power generation should be a global priority, but further industrialisation, especially in China and India, poses the risk of aggravating the situation instead, write the researchers.

The initial investment costs for the construction of a coal power plant are high, but the subsequent operating costs are still relatively low. Power plant operators thus have an economic interest in keeping their plants running for a long time. The best option is therefore not to build any new coal power plants. From a health and environment perspective, we must move away from coal and towards clean renewable energy sources.

Christer Ågren

The study: “Global emission hotspots of coal power generation”, by C. Oberschelp, S. Pfister, C.E. Raptis and S. Hellweg. Published in Nature Sustainability, 2019, doi: 10.1038/s41893-019-0221-6.
Source: ETH Zürich news, 18 February 2019.


In this issue