Characterization of Irreducible Uncertainty in the Future Energy System
The energy system has an intricate relationship with climate change. Burning fossil fuels for energy has a
tremendous impact on global climate, and will continue to do so unless we take
Low or zero-carbon energy technologies such as wind and solar power show great
potential to replace fossil-fuel consumption, and will play a major role in
curbing the carbon dioxide released into the atmosphere. In the past few
decades, investment in these technologies has increased tremendously.
As new energy technologies emerge because of climate change, researchers
have tried to model the future evolution of the energy system. Most of these
models assume that using many different technologies simultaneously will reduce
emissions. But historical evidence suggests that a few technologies tend to
dominate energy systems. Such imbalanced distribution happens as a result of
different rates of technological maturity, costs, subsidies, market conditions
and various path dependencies i.e. all the decisions and outcomes that have
shaped the history of the technology.
Part of our research at the CDMC
focuses on developing a more detailed way of thinking about the future of the U.S.
energy system, about the impacts it may have on the climate system, and the impacts
climate policy will have on it in return. At the same time, we want to
understand the fundamental uncertainty present in all of these issues.
While we do not expect to be able to predict specific details of the energy
system's future, we believe that through historical analysis, technology
assessment and policy analysis, we can develop a much better understanding of
the factors that are likely to shape that future, as well as the policies that
could influence its development.
The researchers involved in this arm of the CDMC plan to study past and present
low-carbon technologies, including wind, solar, fuel cells, and carbon storage.
Some of their goals are to understand the historical course of evolution of
past technologies, to assess situations where government subsidies make sense,
and to study the social implications of alternative energy-system
structures-centralized versus decentralized, gas versus electricity-based
etc.-in the future.
Low-Carbon Energy Systems
Researchers: Inês Lima Azevedo, Engineering and Public Policy, Carnegie Mellon University; Granger Morgan, Engineering and Public Policy, Carnegie Mellon University; Costa Samaras (former affiliate)
In order to avoid the possibly drastic consequences of climate change, large emissions reductions will be necessary. Most of these emissions are linked to our energy systems, largely through the consumption of fossil fuels. Burning fossil fuels for energy has a tremendous impact on global climate, and will continue to do so unless we take preventive steps.
Part of our research at the CDMC focuses on developing a more detailed way of thinking about the future of the U.S. energy system, about the impacts it may have on the climate system, and the impacts climate policy will have on it in return. At the same time, we want to understand the fundamental uncertainty present in all of these issues.
We plan to assess and compare how energy and climate policies and technology choices will affect different economic sectors (residential, commercial, industrial, transportation and the electric sector).
Public Outreach: Cap and Trade is Not Enough: Improving US Climate Policy (March 2009)
"Energy Efficiency and Conservation: A bright idea with solid state lighting?" - I.L. Azevedo, 2007; Proceedings of the European Council for an Energy Efficient Economy Summer Study (ECEEE), La Colle sur Loup, France (La Colle sur Loup, France). [ BibTeX | XML | Full paper ]
"Impact of Battery Weight and Charging Patterns on the Economic and Environmental Benefits of Plug-in Hybrid Vehicles" - C.S. Shiau, C. Samaras, R. Hauffe, J.J. Michalek, January 11-15 2009; 2009 Annual Meeting of the Transportation Research Board, Washington, DC. [ BibTeX | XML | Full paper ]
"Long-term Electric System Investments to Support Plug-in Hybrid Electric Vehicles" - S. Blumsack, C. Samaras, P. Hines, July 20-24 2008; Proceedings of the IEEE Power Engineering Society 2008 General Meeting (Pittsburgh PA). [ BibTeX | XML | Full paper ]
"Plug-in Hybrid Vehicle Simulation: How battery weight and charging patterns impact cost, fuel consumption, and CO2 Emissions" - R. Hauffe, C. Samaras, J.J. Michalek, Auguest 3-6 2008; 2008 ASME Design Engineering Technical Conferences & Computer and Information in Engineering Confere, New York, NY. [ BibTeX | XML ]
"Policies to Promote Plug-in Hybrid Electric Vehicles for Greenhouse Gas Emissions Reductions and Oil Displacement" - C. Samaras, C. Hendrickson, H.S. Mathews, M.G. Morgan, January 11-15 2009; 2009 Annual Meeting of the Transportation Research Board, Washington, DC. [ BibTeX | XML | Full paper ]
"The Transition to Solid-State Lighting" - I.L. Azevedo, M.G. Morgan, F. Morgan, Proceedings of the IEEE, March 2009, 481-510 (ISSN: 0018-9219). [ BibTeX | XML | Full paper ]
The Technical and Economic Feasibility of Solar Photovoltaic Technology
Aimee Curtwright, Granger Morgan, Engineering and
To establish how much we can know
about future energy technologies and systems, we need to understand the likely
characteristics and performance of currently dominant technologies. We also
need to understand the path dependencies of energy systems, how factors such as
social choices, R&D investment and policy environments could lead to
different plausible technology futures.
In this project, we are focusing on determining the technical and economic
feasibility of solar energy technology. We are assessing both current and
emerging technologies, with an emphasis on photovoltaic (PV) cells, which are
the most common way to harness solar power with semiconductors that convert
light energy to electricity.
Various PV technologies are at different stages of maturity and cost
competitiveness. Whether or not to pursue improvements through basic research,
through advanced engineering design and methods, or through large-scale
manufacturing will depend on the assessed maturity and the overall promise of
the individual PV technology.
Photovoltaics can contribute significantly to carbon
dioxide reductions, but their costs are still unacceptable. We are trying to
assess the obstacles in the technology behind PV cells that need to be overcome
to lower costs, and at what timescales this would happen. While a lot about
solar technology's future is unknown, we want to see what different technology
pathways are possible, and evaluate their relative risks and likelihood.
We plan to survey existing literature as well as perform an expert elicitation
in the form of a survey for a handpicked group of solar experts in order to
evaluate where various PV technologies are headed.
Solar research will not progress without the appropriate funding allocation; we
aim to develop a reference guide for the energy policy makers who make research
investment decisions. By studying the trends in various technologies and by
analyzing their benefits and drawbacks, we can understand what research and
policy factors will help the advancement of solar PV technology. This will help
us create a concise analysis that could serve as a reference guide.
Public Outreach Materials - 2006 (pdf)
"Expert Assessments of Future Photovoltaic Technologies" - A.E. Curtright, M.G. Morgan, D.W. Keith, Environmental Science & Technology, Vol. 4, No. 24, 2008, 9031-9038. [ BibTeX | XML | Full paper ]
"The Character of Power Output from Utility-Scale Photovoltaic Systems" - A.E. Curtright, J. Apt, Progress in Photovoltaics, Vol. 16, No. 3, 2008, 241-247. [ BibTeX | XML | Full paper ]
Government Investment Decisions for Renewable Energy Technologies
Constantine Samaras (former affiliate), Granger Morgan, Engineering and
Carnegie Mellon University
The government can influence the development and adoption of
renewable energy in a variety of ways-funding technology research; providing
tax breaks or subsidies for production, generation, or consumption; providing
deployment incentives; and regulatory requirements. The method of intervention
used depends on the technology being considered, and its state of progress.
We want to examine a portfolio of renewable energy
technologies and perform a technical assessment of which government strategies
are most appropriate for each technology. We want to explore the question of
when a technology should receive subsidies so that people can adopt it easily
and learn from use, and when investments should be made in basic research
We are starting with analyzing the engineering and policy
decisions that have resulted in the successful evolution of modern wind energy
into the fastest growing, most popular renewable energy source in the world,
which will surely play a key role in a low-carbon future.
In the United States, which has the second largest wind
market after Germany, wind energy technology is benefiting from the federal
government's production tax credits as well as state-level renewable portfolio
standards. As a result, wind power is competitive with traditional coal-based
electric power generation. The total installed capacity in the
December 2004 was 6740 megawatts, enough to power 1.6 to 2 million households a
The factors that have led to wind energy's success include
technological innovations in wind turbine design influenced by traditional
engineering disciplines, as well as gains from learning, specialization, and
economies of scale provided by market growth and public policy. We are
analyzing trends in wind power development to see which of these factors have
led to the greatest reduction in energy costs.
After the wind energy work, we will pursue similar research
in solar photovoltaics and biofuels.
We plan to develop a practical guide for policymakers who set, analyze, and
evaluate alternative energy policy actions, as well as for engineers who
design, build, operate, and maintain alternative energy infrastructure, so that
we can maximize the successful adoption of these energy technologies.
Public Outreach Materials - 2006 (pdf)
CO2 Capture from Ambient Air
Researchers: Joshuah Stolaroff (former affiliate), Engineering and Public Policy,
University; David Keith,
University of Calgary,
Greg Lowry, Civil and Environmental Engineering,
Alternative energy sources such as wind and solar power are
seeing a slow increase in their share of energy production in the
But fossil fuels are still the overwhelmingly dominant energy source in the
country. In 2003, renewables accounted for only 6
percent of the total energy consumed in the country. Many experts agree that
it's going to be difficult to overcome the inertia involved in our dependence
on coal and oil for more than two centuries.
As a near to medium-term solution, carbon capture and
storage could contribute to emissions reductions substantially, given the
extent of emissions reductions needed to stabilize atmospheric carbon dioxide
concentrations. Capturing CO2 and sequestering it into the earth
will reduce emissions while giving us more time to slowly phase out fossil
fuels and their associate infrastructure, and thus reduce related social costs.
Nearly all of the current research on carbon capture focuses
on capturing CO2 from point sources such as power plants. These
research plans typically involve capturing CO2 from flue gas,
compressing it and transporting it in pipelines to a sequestration site, where
it can be stored either by injecting into the ground or some other method.
We are working on a system that can capture carbon dioxide
directly from ambient air, a process called air capture. This eliminates the
need for a CO2-transportation infrastructure, since the capture unit
can be placed at a favorable sequestration site. In addition, this strategy has
the advantage that it can capture emissions from any sector, including diffuse
sources such as automobiles.
We have developed a prototype system based on capture using
a chemical sorbant that can be regenerated. The land
use requirements for this air capture system are potentially very small. All
the chemicals involved are inexpensive, abundant and relatively benign, and the
processes are all well understood as current industrial-scale practices. Moreoever, it's a system that could be engineered with
existing technology and which can be scaled to capture a significant fraction
of CO2 emissions without depleting scarce resources.
According to our initial estimates, the cost for this
process turns out to be higher than the cost of capture from point sources. But
it is significantly cheaper than other means of reducing carbon emissions from
the transportation sector, such as switching to hydrogen powered vehicles.
Public Outreach Materials - 2006 (pdf)
Synthetic Fuel Emissions
More Coming Soon
Public Outreach Materials - 2006 (pdf)