Project 1

Modeling Emissions from Ener​gy Transitions


Kenneth Gillingham, (Yale)
Benjamin Hobbs, (Johns Hopkins)

Julie Zimmerman (Yale), Hugh Ellis (Johns Hopkins), Matthew Eckelman (Northeastern), John Weyant (Stanford), Michael Wara (Stanford)

Yale (New Haven, CT), Johns Hopkins (Baltimore, MD), Northeastern (Boston, MA), Stanford (Stanford, CA)


Transitions in the U.S. energy system will profoundly influence regional emissions and air quality. Examples include adoption of electric vehicles; expanding distributed electric generation, renewables, and demand response; growing unconventional oil and natural gas; climate change impacts on energy use; and a transition to a carbon-constrained economy. We will inform sound policy by:

  1. developing scenarios describing the transitions;
  2. modeling these scenarios in the state-of-the-art U.S. DOE National Energy Modeling System (NEMS) to project future energy use, technology adoption, and emissions by region;
  3. using Life Cycle Assessment (LCA) to model additional pollutants not currently in NEMS including manufacture of technologies; and
  4. downscaling emissions to temporal and spatial scales needed for air quality simulation and evaluating alternative downscaling methods that account for regional policies, siting of new generation, and changed operations.

Results will be used by Projects 3 and 4 to estimate effects on air quality and health. Findings will provide insights on regional effects of energy transitions, including impacts upon vulnerable populations. Sensitivity analyses will bound the estimates’ uncertainty. We hypothesize that the energy transitions will be mediated by energy, transport, and other factors that can be influenced by policy, pointing to novel solutions that recognize regional aspects of emissions and air quality and account for a changing climate.


To achieve the objectives we will:

  1. develop detailed policy-relevant scenarios through reviewing the literature and collaborating with the Decision Maker Team of air directors and the Policy and Decision Making Unit;
  2. model detailed, novel scenarios, including modifiable factors, through NEMS for 4 decades;
  3. apply LCA to expand the suite of emissions modeled; and
  4. implement a state-of-the-art NEMS-SMOKE modeling approach to emissions downscaling, with comparison to alternative methods that capture sub-regional policies.
Expected Results

The comprehensive NEMS projections of major energy transitions will provide guidance on the most effective modifiable factors for protecting regional environmental, health, and societal well-being in the context of a changing climate. The LCA will provide an innovative broader perspective upon emissions from the transitions, including from manufacturing. Alternative downscaling approaches will show how impacts can be mediated by regional policy. Key outcomes include a deeper understanding of the regional effects of air, energy, and climate policies, as they interact with the energy transitions. The project will bridge disciplines, enhancing state-of-the-art science in air, climate, and energy modeling.