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Stepp Mayes

Postdoctoral Researcher

Hometown: Detroit, MI

Curriculum Vitae

Stepp was born in Detroit, MI in 1996. He earned his bachelor’s degree from the University of Michigan in Engineering Physics and Environmental Engineering in 2018. After graduating Stepp worked at the Environmental Protection Agency as a research fellow as part of the EPA’s Ports Initiative as an ORISE Fellow. He moved to Los Angeles in the fall of 2019 to join S3 and pursue his PhD in Environmental Engineering, defending his dissertation in November 2023. He is currently working as a Postdoc in the S3 group.

Research Interests

As a PhD student, Stepp 1) developed statistical models to quantify marginal emissions factors and 2) investigated how pre-cooling residential buildings can be leveraged as a demand side management strategy in grids with high solar generation. As a Postdoc, Stepp has continued to analyze the decoupling of electricity demand and emissions on modern grids through projects on household electricity-associated emissions and the ability of load-shifting to provide grid benefits.

 Awards and Honors

  • Behavior, Energy, and Climate Change Conference: Student Fellowship (2023)
  • Ershaghi Center for Energy Transition: Seed Funding Recipient (2022)
  • SoCal Research Symposium Workshop: Best Pitch (2022)
  • ORISE Fellow- 2019


  • Ph.D. Environmental Engineering (2023)
  • M.S. Green Technologies University of Southern California (2021)
  • Bachelor of Science in Engineering- University of Michigan, Ann Arbor (2018)

Peer-Reviewed Journal Publications:

  • Mayes, S, Klein, N., & Sanders, K. T. (2024). Using neural networks to forecast marginal emissions factors: A CAISO case study. Journal of Cleaner Production, 434, 139895.
  • Mayes, S, Zhang, T., & Sanders, K. T. (2023). Residential precooling on a high-solar grid: impacts on CO2 emissions, peak period demand, and electricity costs across California. Environmental Research: Energy, 1(1), 015001.
  • Zohrabian, A., Mayes, S., & Sanders, K. T. (2023). A data-driven framework for quantifying consumption-based monthly and hourly marginal emissions factors. Journal of Cleaner Production, 396, 136296.
  • Mayes, S., & Sanders, K. (2022). Quantifying the electricity, CO2 emissions, and economic tradeoffs of precooling strategies for a single-family home in Southern California. Environmental Research: Infrastructure and Sustainability, 2(2), 025001.

Oral and Poster Presentations

  • Stepp Mayes. “Demand-Side Management of Electricity.” Guest Speaker at Honors Colloquium- University of Southern California, Los Angeles, California. Feb., 2024
  • Joseph Ko, Yun Li, Stepp Mayes, McKenna Peplinski, Hannah Schlaerth, Pouya Vahmani, George A Ban-Weiss and K.T Sanders. “Modeling the Spatiotemporal Distribution and Meteorological Impacts of Anthropogenic Heat in Los Angeles.” AGU Fall Meeting, San Francisco, California. Dec., 2023.
  • Stepp Mayes, Nicholas Klein, Natalia Ratner, K. T. Sanders. “Forecasting Marginal Emissions Factors with Neural Networks.” AGU Fall Meeting, San Francisco, California. Dec., 2023.
  • McKenna Peplinski, Stepp Mayes, Kelly Sanders. “Improving AC Penetration Estimates for Demand Response.” AGU Fall Meeting, San Francisco, California. Dec., 2023.
  • Stepp Mayes, Kelly Sanders. “Forecasting Marginal Emissions Factors.” SoCal Research Symposium, Los Angeles, CA. 2023
  • Stepp Mayes, Nicholas Klein, Natalia Ratner, Kelly Sanders. “The Social Value of Demand-Side Management.” Behavior Energy and Climate Conference, Sacramento, California. Nov. 2023
  • Stepp Mayes, Kelly Sanders. “Calculating Marginal Emissions Factors for Demand-side Management on a High-Renewable Grid.” American Geophysical Union, Chicago, IL. Dec., 2022
  • Stepp Mayes, Kelly Sanders. “The Emissions Impacts of Demand-Side Management on a High Renewable Grid.”SoCal Research Symposium, Los Angeles, CA. 2022
  • Stepp Mayes, Kelly Sanders. “Achieving peak load and CO2 emissions reductions by aligning AC usage with solar energy availability through residential precooling strategies.” American Geophysical Union, New Orleans, LA. Dec., 2021
  • Stepp Mayes, Kelly Sanders. “Cooling our Homes with the Sun: Exploring Precooling Strategies to Reduce Green-
    house Gas Emissions.” American Geophysical Union, Remote. Dec., 2020