At the 2009 U.N. Climate Change Conference (UNCC) in Copenhagen, more than 100 countries pledged to reduce their carbon dioxide emissions in the coming decades to help stabilize, if not reverse, the current global warming trend. Achieving that goal will require aggressive energy policy and technology strategies that not only meet carbon emissions targets, but also accommodate energy demand, enhance national security and preserve economic well-being. It’s an especially daunting challenge in countries like the U.S., whose annual total and per capita carbon dioxide emissions are among the world’s highest, and whose energy mix is dominated by fossil fuels.
Overcoming that challenge will ultimately require a synergistic combination of technology, business and policy innovation aimed at developing low-carbon, low-cost heating, lighting and mobility solutions, said Ernest J. Moniz, director of the MIT Energy Initiative (MITEI), in his Presidential Lecture on Energy and Sustainability on April 14 at the Photonics Center. A seasoned expert in nuclear physics and energy technology and policy, and professor of physics and engineering systems at MIT, he has served as Under Secretary of the Department of Energy and sits on President Obama’s Council of Advisors for Science and Technology.
Setting Emissions Targets
Moniz pointed to the Copenhagen Accord, a nonbinding agreement forged at the UNCC that called for developed countries to submit carbon emission reduction targets for 2020, as an important step in transitioning to a low-carbon future.
“I believe that this is the beginning of a movement toward the large-emitting countries basically deciding what they’re going to do,” he said, referring to 20 countries responsible for up to 90 percent of the globe’s man-made carbon dioxide emissions. “The key negotiation is among the large emitters, and then you bring in the other countries.”
One of the largest emitters, the U.S. pledged to reduce carbon dioxide emissions 17 percent below 2005 levels by 2020, and 83 percent by 2050. Moniz argued that the U.S. could achieve the 2020 goal with only two major tools: demand reduction through increased energy efficiency — especially in buildings and transportation — and replacing coal plants with natural gas.
Establishing a New Energy Mix
“Natural gas is about two times less carbon-intense as coal, but these old coal plants have poor efficiency also,” Moniz observed, noting that natural gas plants could provide as much as four times the carbon reduction as inefficient coal plants, and with far less capital investment. Domestic supplies have increased considerably in the past five years due to unconventional gas exploration technologies.
To achieve further carbon emission reductions after 2020, Moniz envisioned an energy mix consisting of natural gas; carbon capture and sequestration (CCS) technology at the more energy-efficient coal plants; renewable energy technologies such as solar and wind; and nuclear power, a carbon-free source that now accounts for about 20 percent of U.S. electricity consumption. He recommended that beyond 2020, the U.S. focus on developing low- to zero-carbon energy sources to replace the use of oil in motor vehicles and coal-based electricity in buildings.
Offering his own “Michelin Guide” to low-carbon future technology pathways, Moniz said, “My three-star technologies are efficiency — especially in buildings and vehicles — and carbon-free electricity. A low-carbon future [requires that we] fully ‘de-carbonize’ the power sector by midcentury.”
Moniz’s presentation was sponsored by the BU Clean Energy and Environmental Sustainability Initiative (CEESI), a collaboration of six Colleges and Schools at BU, including the College of Engineering, which hosted the event. CEESI faculty members, many based at the College of Engineering, are leading cross-disciplinary and world-class research efforts on problems such as the smart grid, the hydrogen economy, green manufacturing and smart lighting.