Ryan E. Hanna

Post-doctoral Scholar, 2017–2018
PhD in Engineering Sciences (Mechanical Engineering), 2017 UC San Diego

Dissertation and research advisors:
Prof. Jan Kleissl (dissertation co-PI)
Department of Mechanical and Aerospace Engineering
Director, Center for Energy Research
University of California, San Diego

Prof. David Victor (dissertation co-PI)
School of Global Policy and Strategy
Director, Laboratory on International Law and Regulation
University of California, San Diego

Bill Torre
Center for Energy Research
Program Director of Energy Storage Systems
University of California, San Diego


My research has spanned several topics and projects over 6+ years at UC San Diego. The consistent, core focus has been modeling, optimization, and simulation of distributed energy resources—in particular microgrids. I include below brief summaries of research.

Modeling microgrid reliability and emissions. Many believe the future electric grid will be low-carbon and perhaps decentralized. Microgrids may be a key enabler of decentralization. In this work, I built an optimization model for microgrids that sizes and schedules resources in the microgrid and that considers revenue streams from providing energy (power, heat, cooling) locally as well as from improving electric service reliability for customers within. We have studied why and how customers of different classes invest in, and benefit from, microgrids that improve reliability. We have also looked at policy aspects around emissions—specifically, how customer microgrids impact greenhouse gas emissions from the electric power sector.

Microgrid business cases. Stand-alone distributed generation (e.g. solar PV, electric energy storage, CHP, thermal storage) and microgrids (which control these technologies and can island from the bulk grid) may shape the future electric grid. This work investigates the extent to which decentralized energy can help decarbonize the grid, and in what ways decentralized energy is economically optimal (or not). Future regulations that might affect the economics of microgrids are far from certain, however. We are modeling policy, technology and market variables to understand how regulations like carbon taxes affect the economic feasibility, or “business case”, for microgrids. These variables have real consequences; e.g. they may push least-cost investment toward renewables (or not).

Grid integration of solar energy. Solar PV power output is inherently intermittent. When adopted in high penetrations, that intermittency can degrade local power quality and cause voltage excursions or substation back-flow. In this research, we modeled five utility distribution feeders using the model OpenDSS to explore the grid impacts of distributed and centralized PV at increasing penetration levels.

Customer applications for solar+storage systems. Numerous uses for solar PV+battery energy storage (“solar+storage”) systems sited behind-the-meter have been proposed and studied—e.g., load shifting, peak load shaving, PV ramp rate control, and microgrid applications. We have developed optimization algorithms for peak load shaving and PV ramp rate control using a solar+storage system. These algorithms have been simulated in a virtual environment and implemented operationally using real PV systems and second-life electric vehicle battery storage systems at the UC San Diego campus.

Peer-reviewed Publications

  • R. Hanna, J. Kleissl, D.G. Victor, “The impact of microgrid adoption on greenhouse gas emissions from the California electric power sector,” (working paper).
  • R. Hanna, V. Disfani, H. Valizadeh Haghi, D.G. Victor, J. Kleissl, “Improving estimates for reliability and cost in microgrid investment planning models,” J. Renewable Sustainable Energy 11, 045302 (2019). doi: 10.1063/1.5094426.
  • Babacan, O; Abdulla, A.; Hanna R.; Kleissl, J.; Victor, D.G. Unintended effects of residential energy storage on emissions from the electric power system, Environ. Sci. Tech. 2018, 52, 13600–13608. doi: 10.1021/acs.est.8b03834.
  • R. Hanna, V. Disfani, J. Kleissl, “Reliability evaluation for microgrids using cross-entropy Monte Carlo simulation,” IEEE International Conference on Probabilistic Methods Applied to Power Systems (PMAPS) 2018, Jun. 2018. doi: 10.1109/PMAPS.2018.8440421.
  • R. Hanna, V. Disfani, J. Kleissl, D.G. Victor, “A new simulation model to develop and assess business cases for commercial microgrids,” North American Power Symposium (NAPS) 2017, Sep. 2017.
  • Hanna, R., Ghonima, M., Kleissl, J., Tynan, G., Victor, D.G., 2017. Evaluating business models for microgrids: Interactions of technology and policy. Energy Policy 103, 47-61. doi: 10.1016/j.enpol.2017.01.010.
  • R. Hanna, V. Disfani, J. Kleissl, “A game-theoretical approach to variable renewable generator bidding in wholesale electricity markets,” North American Power Symposium (NAPS) 2016, Sep. 2016. doi: 10.1109/NAPS.2016.7747919.
  • I.S. Bayram, V. Zamani, R. Hanna, J. Kleissl, On the Evaluation of Plug-in Electric Vehicle Data of a Campus Charging Network, 2016 IEEE International Energy Conference, EnergyCon 2016, Leuven, Belgium. doi: 10.1109/ENERGYCON.2016.7514026.
  • Hanna, R., Kleissl, J., Nottrott, A., Ferry, M., 2014. Energy dispatch schedule optimization for demand charge reduction using a photovoltaic-battery storage system with solar forecasting. Solar Energy 103, 269-287. doi: 10.1016/j.solener.2014.02.020.

Other Reports

  • R. Hanna, D. Gonatas, K. Murray, J. Kleissl. Development and simulation of battery energy storage and inverter control for PV ramp rate smoothing, Apr 2016. (Report submitted for CSI RD&D5 Subtask 3).
  • D.A. Nguyen, P. Ubiratan, M. Velay, R. Hanna, J. Kleissl, J. Schoene, V. Zheglov, B. Kurtz, B. Torre, V. Disfani. Impact Research of High Photovoltaics Penetration Using High Resolution Resource Assessment with Sky Imager and Power System Simulation, 2015. Available online.
  • W. Torre, R. Hanna, J. Kleissl. Cumulative Impacts of High Penetration of Electric Vehicle Charging and Photovoltaic Generation on Distribution Circuits, 2015. Available online.

Selected Conference Presentations and Invited Talks

  • Seminar: R. Hanna. Pathways for decarbonization: The case of distributed energy via microgrids. UCSD Deep Decarbonization Initiative, La Jolla, CA, 2018.
  • Poster: R. Hanna. Economic modeling of microgrid business cases considering reliability. JCESR Symposium on Energy Storage, La Jolla, CA, 2017.
  • Poster: R. Hanna, D. Victor, V. Disfani, J. Kleissl. The value of reliability for microgrids. DistribuTECH 2017, San Diego, CA, 2017.
  • Paper: R. Hanna, V. Disfani, J. Kleissl. A game-theoretical approach to variable renewable generator bidding in wholesale electricity markets. NAPS 2016, Denver, CO, 2016.
  • Poster: R. Hanna. The business case for microgrids: Current and future trends. EBI Environmental Summit, San Diego, CA, 2016.
  • Keynote Talk: R. Hanna, D. Victor. Squaring microgrid business models with grid decarbonization. CaFFEET 2015, San Francisco, CA, 2015.
  • Poster: R. Hanna, J. Kleissl, A. Nottrott, M. Ferry. Energy dispatch schedule optimization for demand charge reduction using a photovoltaic-battery storage system with solar forecasting. EESAT 2013, San Diego, CA, 2013.

Other Appointments and Affiliations

  • International Institute for Applied Systems Analysis (IIASA), Young Scientists Summer Program, Laxenburg, Austria, 2017.
  • Deep Decarbonization Initiative, UC San Diego, 2016–present.
  • Center for Energy Research, UC San Diego, 2014–2018.


  • Guest Lecturer. GPGN 491 – Fundamentals of Energy Systems and Innovation. Winter 2019. Instructors: Profs. David Victor, George Tynan.
  • Teaching Assistant. MAE 126a – Environmental Engineering Lab.  Winter 2016.  Instructor: Prof. Jan Kleissl.
  • Teaching Assistant. MAE 110a – Thermodynamics.  Winter 2014. Instructor: Prof. Jan Kleissl.
  • Teaching Assistant. MAE 121 – Air Pollution Transport and Dispersion Modeling.  Spring 2013. Instructor: Mark Bennett.


Ph.D. (2017) Mechanical Engineering. University of California, San Diego. Dissertation: Business cases for microgrids: Modeling interactions of technology choice, reliability, cost, and benefit. Co-PIs: Jan Kleissl, David Victor.
M.S. (2013) Mechanical Engineering. University of California, San Diego, 2013. GPA: 3.69.
B.S. (2011) Mechanical Engineering. Washington University in St. Louis, St. Louis, Missouri. 2011. GPA: 3.97.
B.A. (2009) Physics, Mathematics minor. Pacific Lutheran University, Tacoma, Washington, 2009. GPA: 3.73.


Ryan Hanna
rehanna [at] ucsd [dot] edu