Efrain O’Neill-Carillo Ph.D.


Efrain O’Neill-Carillo Ph.D.

Senior Member of Technical Staff

Contact Information

Efrain O’Neill-Carillo / 505-844-8976


Efrain O’Neill-Carrillo is a member of the technical staff in the Renewable and Distributed Systems Integration group. His work focuses on distributed energy resources and islanded power systems. This includes PV hosting capacity analysis and resilience power solutions for end of line and vulnerable communities with emphasis on microgrids. He is also identifying strategic directions for new energy research collaborations between Sandia and the University of Puerto Rico-Mayaguez (UPRM). In addition to his position at Sandia, he is an electrical engineering professor and researcher at UPRM, an ABET evaluator and a Registered Professional Engineer. He led the first distributed energy generation studies in Puerto Rico and the first local microgrid studies while advising local governments and state agencies there regarding energy projects. Efrain will return to UPRM in 2021 where he plans to combine Sandia-developed resiliency and renewable energy tools with his research on sustainability, power quality, energy policy, and regulatory analysis to improve the university’s capabilities in support of distributed energy resources growth.


    Ph.D., Electrical Engineering, Arizona State University (ASU), Tempe, Arizona – 1999
    Master of Science in Electrical Engineering, Purdue University, West Lafayette, Indiana – 1995

    Bachelor of Science in Electrical Engineering, Magna Cum Laude, University of Puerto – 1994

    Key Publications


      C. J. Newlun, F. M. Currie, E. O’Neill-Carrillo, E. Aponte Bezares, R. H. Byrne. “Energy Resource Planning for Puerto Rico’s Future Electrical System.” IEEE PES T&D Conference and Exposition, 2020.

      E. Parés, E. O’Neill-Carrillo, F. Andrade. “Best Practices for Microgrids applied to a Case Study in a Community.” IEEE ISGT, 2020.


      E. O’Neill-Carrillo and A. Irizarry-Rivera, “How to Harden Puerto Rico’s grid against hurricanes,” IEEE Spectrum, vol. 56, no. 11, pp. 42-48, Nov. 2019.