Direct Current Can Amp Up Existing Transmission Lines

The U.S. energy system has seen sweeping changes in the past two decades. Natural gas replaced coal as the dominant fossil source of power generation, and wind and solar energy now contribute roughly 9% of the nation's electricity, compared to almost none 20 years ago. Because of these changes, less carbon is being emitted by the power sector per unit of electricity produced. A transition toward a low-carbon power sector has begun. Meaningful decarbonization of the energy system, however, will require not only new sources of energy but also new and expanded pathways to bring that clean power to consumers, especially as demand for electricity grows in the coming decades. How to expand the capacity of the U.S. electrical grid is the subject of a recent paper from researchers in Carnegie Mellon University's Engineering and Public Policy (EPP) department, published in the Proceedings of the National Academy of Sciences. "There is a widespread belief that the move to decarbonizing our energy system is going to give rise to more electrification,” said Granger Morgan, the Hamerschlag University Professor of Engineering, and senior author of the study, "and we'll have to move that power, somehow.