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Don’t coal it a comeback

Coal fired power plants are at the forefront of technological advances and will have a more important role in reducing global carbon emissions than renewable sources, writes Tim Probert.

Climate change, climate change, climate change. Those two words have dominated the media in recent months. While almost everyone is in agreement that it is occurring and that something needs to be done to reduce harmful emissions, how this will be achieved is a matter of stark debate. Mention the words ‘coal’ and ‘nuclear power’ and many environmentalists will spit blood. It is obvious, however, that these two controversial sources of energy must play a leading role in a cleaner future, albeit for differing reasons.

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To suggest some years ago that coal is the future of green energy would have produced snorts of derision, perhaps at least in Western Europe. Coal is dirty, they said, prehistoric, a relic of the industrial age. Surely the future is solar power or wind turbines? The reality is, of course, coal is very much here to stay. It will be a very, very long time before company directors will deem a small carbon footprint more important than a healthy balance sheet. There is no getting away from the fact that coal is cheap. Very cheap.

Coal can provide usable energy at a cost of $1-2 per MMBtu, compared to $6-12 per MMBtu for oil and natural gas. Reserves are colossal and distributed relatively evenly in each continent excluding Antarctica – crucial for secure supplies given the current political climate. The USA Energy Information Administration estimates that at the current global annual consumption of 15 TW, there is enough coal to provide the entire planet with all of its energy for 600 years.

The downside to all this cheap and abundant energy is, of course, high carbon dioxide (CO2) and other air pollutant emissions that will be the subject of ever increasing regulation. Coal is the largest contributor to global CO2 emissions from energy use (41 per cent) and its share is projected to increase. The USA alone, which generates 50 per cent of its electricity from coal, produces 1.5 billion tonnes of CO2 from its coal fired plants every year. The problem is clear to see.

Faced with this dilemma, the Massachusetts Institute of Technology (MIT) began a two-year study to explore solutions to this problem and last month it published the findings in its report, The Future of Coal: Options For A Carbon-Constrained World. In it, the authors conclude that “CO2 capture and sequestration (CCS) is the critical enabling technology that would reduce carbon emissions significantly, while also allowing coal to meet the world’s pressing energy needs.”

The report argues that the availability of CCS will make a significant difference in the utilization of coal by 2050 regardless of the level of CO2 prices or the assumption that the usage of nuclear power will increase from current levels. “With CCS, more coal is used in 2050 than today, while global CO2 emissions from all sources of energy are only slightly higher than today’s level, ‘ says the report. ‘A major contributor to global emissions reduction for 2050 is the reduction in CO2 emissions from coal to half or less of today’s level.”

The problem with CCS is that while the theory is sound it has not yet been proven on a satisfactory scale. The MIT report recognises this and calls for a successful large-scale demonstration of the technical, economical and environmental performance of the technologies that make up all the major components of an integrated CCS system, namely capture, transportation and storage.

Condemning current government and private sector programmes to implement such demonstrations as completely inadequate, the MIT report identifies two areas of high priority. Firstly, it calls for successful CO2 sequestration demonstrations at a scale of one million tonnes per year in several geologies. It estimates that the number of at-scale CCS projects is three for the USA and ten worldwide to cover the range of likely accessible geologies for large-scale storage.

Secondly, MIT wants successful demonstration of CO2 capture for several alternative coal combustion and conversion technologies, such as integrated gasification combined-cycle (IGCC) coal fired plants. At present IGCC is the leading candidate for electricity generation with CO2 capture because it is estimated to have lower costs than pulverized coal with capture; however, neither IGCC nor other coal technologies have yet been demonstrated with CCS.

The Future of Coal report markedly warns governments to avoid falling into the trap of picking out a technology “winner” at a time when there is a great deal of research into coal combustion and conversion development activity underway the world over. MIT suggests that IGCC plants with CCS should complement other technologies such as oxygen fired pulverized coal combustion, especially with lower quality coals.

Moreover, financial support from governments for “clean coal” projects should be geared towards CCS. Citing the USA’s 2005 Energy Act, which contains provisions that authorizes assistance for IGCC or supercritical pulverized coal plants with or without CCS, MIT argues that assistance should be directed only to plants with CCS, either for new plants or for retrofit applications on existing plants.

The race has begun to find the best methods to clean up coal, and capture and sequester CO2. The reward of lucrative contracts is “the carrot” and the threat of strictly regulated carbon trading and emissions control “the stick”. Industrializing nations are playing catch up in all this, but if the technology is accessible they will not hesitate to take up the baton.