An interdisciplinary MIT faculty group examined the role of coal in a world where constraints on carbon dioxide emissions are adopted to mitigate global climate change. Their report, The Future of Coal, examines how the world can continue to use coal, an abundant and inexpensive fuel, in a way that mitigates, instead of worsens, the global warming crisis.
The report is extremely comprehensive and in my view very objective and should play an important role in determining government policy regarding coal fired power plants.
They are especially critical of the government picking a technology "winner." Although IGCC is the lowest cost solution at the present they contend that super critical pulverized coal plants or oxycombustion plants could be competitive and deserve more funding. They also conclude that a significant reduction of carbon emissions is possible only when a significant price is placed on CO2 emissions.
The remainder of this post is composed of excerpts of key parts of the report.
This report evaluates the technologies and costs associated with the generation of electricity from coal along with those associated with the capture and sequestration of the carbon dioxide produced coal-based power generation. Growing electricity demand in the U.S. and in the world will require increases in all generation options (renewables, coal, and nuclear) in addition to increased efficiency and conservation in its use. Coal is likely to remain an important source of energy in any conceivable future energy scenario.
The report concludes that carbon capture and sequestration (CCS) is the critical enabling technology to help reduce CO2 emissions significantly while also allowing coal to meet the world's pressing energy needs.
According to Dr. Deutch, Institute Professor, Department of Chemistry "As the world's leading energy user and greenhouse gas emitter, the U.S. must take the lead in showing the world CCS can work. Demonstration of technical, economic, and institutional features of CCS at commercial scale coal combustion and conversion plants will give policymakers and the public confidence that a practical carbon mitigation control option exists, will reduce cost of CCS should carbon emission controls be adopted, and will maintain the low-cost coal option in an environmentally acceptable manner."
The central message of the report is:
Demonstration of technical, economic, and institutional features of carbon capture and sequestration at commercial scale coal combustion and conversion plants will
- give policymakers and the public confidence that this carbon mitigation control option is practical for broad application,
- shorten the deployment time and reduce the cost for carbon capture and sequestration should a carbon emission control policy be adopted, and
- maintain opportunities for the use of coal in a carbon constrained world in an environmentally acceptable manner.
Key findings in this study:
- Coal is a low-cost, per BTU, mainstay of both the developed and developing world, and its use is projected to increase. Because of coal's high carbon content, increasing use will exacerbate the problem of climate change unless coal plants are deployed with very high efficiency and large scale CCS is implemented.
- CCS is the critical enabling technology because it allows significant reduction in CO2 emissions while allowing coal to meet future energy needs.
- A significant charge on carbon emissions is needed in the relatively near term to increase the economic attractiveness of new technologies that avoid carbon emissions and specifically to lead to large-scale CCS in the coming decades. We need large-scale demonstration projects of the technical, economic and environmental performance of an integrated CCS system. We should proceed with carbon sequestration projects as soon as possible. Several integrated large-scale demonstrations with appropriate measurement, monitoring and verification are needed in the United States over the next decade with government support. This is important for establishing public confidence for the very large-scale sequestration program anticipated in the future. The regulatory regime for large-scale commercial sequestration should be developed with a greater sense of urgency, with the Executive Office of the President leading an inter agency process.
- The U.S. government should provide assistance only to coal projects with CO2 capture in order to demonstrate technical, economic and environmental performance.
- Today, IGCC appears to be the economic choice for new coal plants with CCS. However, this could change with further RD&D, so it is not appropriate to pick a single technology winner at this time, especially in light of the variability in coal type, access to sequestration sites, and other factors. The government should provide assistance to several "first of a kind" coal utilization demonstration plants, but only with carbon capture.
- Congress should remove any expectation that construction of new coal plants without CO2 capture will be "grandfathered" and granted emission allowances in the event of future regulation. This is a perverse incentive to build coal plants without CO2 capture today.
- Emissions will be stabilized only through global adherence to CO2 emission constraints. China and India are unlikely to adopt carbon constraints unless the U.S. does so and leads the way in the development of CCS technology.
- Key changes must be made to the current Department of Energy RD&D program to successfully promote CCS technologies. The program must provide for demonstration of CCS at scale; a wider range of technologies should be explored; and modeling and simulation of the comparative performance of integrated technology systems should be greatly enhanced.
[Their findings are elaborated in chapter 8 of the report. The complete text of their finding on the relative merits of coal power plants is as follows]
It is premature to select one coal conversion technology as the preferred route for cost-effective electricity generation combined with CCS. With present technologies and higher quality coals, the cost of electricity generated with CCS is cheaper for IGCC than for air or oxygen driven SCPC. For sub-bituminous coals and lignite, the cost difference is significantly less and could even be reversed by future technical advances. Since commercialization of clean coal technology requires advances in R&D as well as technology demonstration, other conversion/combustion technologies should not be ruled out today and deserve R&D support at the process development unit (PDU) scale.
[The complete text of their finding regarding the need for a significant charge on carbon emissions is as follows]
A global carbon charge starting at $25 per ton of CO2 emitted (or nearly $100 per tonne of carbon), imposed initially in 2015 and rising at a real rate of 4% per year, will likely cause adjustments to energy demand, supply technologies and fuel choice sufficient to stabilize mid-century global CO2 emissions from all industrial and energy sources at a level of 26 to 28 gigatons of CO2 per year. Depending on the expansion of nuclear power, the use of coal increases from 20% to 60% above today’s level, while CO2 emissions from coal are reduced to half or a third of what they are today. This level of carbon charge implies an increase in the bus bar cost of U.S. electricity on average of about 40%, or about 20% of the retail cost. A significant contributor to the emissions reduction from coal is the introduction of CCS, which is utilized as an economical response to carbon charges at these levels. In the EPPA model simulations, approximately 60% of coal use employs CCS by 2050 with this carbon charge.