Potential contribution of coal to the future global energy system

Using a bottom-up type global energy model, this article explores in detail the potential role of coal over the 21st century and focuses on the prospects for coal gasification-based conversion technologies with CO 2 capture and sequestration (CCS) under the CO 2 stabilization target of 550ppm. The results show that even in the CO 2 -constrained world, coal can remain one of the important primary energy sources throughout the century on the condition that the resulting CO 2 is properly captured and sequestered. Coal’s competitiveness in such a world would increase with the introduction of CCS, but decrease with the leak rate for CO 2 stored underground. For the optimal coal use, a common trend toward producing convenient and clean final energy carriers via gasification is observed. Under the CO 2 constraint, coal is increasingly converted via gasification with CCS into electricity and hydrogen, thereby providing CO 2 -neutral energy carriers and facilitating CO 2 capture, which helps China and India develop in a sustainable manner. These findings prove to be robust with respect to the costs of gasification-based conversion technologies and CCS. It is suggested that the establishment of reliable CCS technologies and low-cost gasification-based conversion technologies and their transfer to developing regions would raise the value of coal and provide energy security benefits under the CO 2 constraint. However, it is also indicated that large-scale introduction of coal with CCS into leaky reservoirs would cause large CO 2 emissions from leaks over the very long term. Copyright Springer Japan 2006