Getting to Zero Carbon Emissions in the Electric Power Sector

19 December 2018
Max Luke, et. al.

In an article published in Joule, NERA Consultant Max Luke, postdoctoral Environmental Fellow at Harvard University Jesse D. Jenkins, and Executive Director of the Energy Innovation Reform Project Samuel Thernstrom review and distill insights from 40 studies on pathways toward “deep decarbonization,” defined as an 80%–100% reduction in carbon dioxide (CO2) emissions from current levels. The authors note that the studies collectively outline and evaluate two overall paths to decarbonize electricity. One path relies primarily on variable renewable energy sources, chiefly wind and solar power, supported by energy storage, greater flexibility from electricity demand, and continent-scale expansion of transmission grids. The second path relies on a wider range of low-carbon resources, including wind and solar, as well as “firm” resources such as nuclear, geothermal, biomass, and fossil fuels with carbon capture and storage (CCS).

Whichever path is taken, the authors find strong agreement in the literature that reaching near-zero emissions is much more challenging—and requires a different set of low-carbon resources—than comparatively modest emissions reductions (e.g., CO2 reductions of 50%–70%). This is chiefly because more modest goals can readily employ natural gas-fired power plants as firm resources. Pushing to near-zero emissions requires replacing the vast majority of fossil-fueled power plants or equipping them with CCS. The authors conclude that a strategy that seeks to improve and expand the portfolio of available low-carbon resources, rather than restrict it, offers a greater likelihood of affordably achieving deep decarbonization.