Recently published storage portfolios paper

• Links to Paper and Research Brief
• Key Findings
• Methodology
  • Modeling of Different Storage Technologies
  • Modeling of Different Geographic Regions
• Acknowledgements

Links to Paper and Research Brief

I’m thrilled to share my first first-author paper, titled “The Influence of Regional Geophysical Resource Variability on the Value of Single- and Multistorage Technology Portfolios”, published in ACS Environmental Science & Technology!

In this paper, we explore the value of single- and multi-storage portfolios in electricity systems reliant on solar and wind energy.

For a concise 2-page summary, see our Research Brief.

Key Findings

1. Long-duration storage may also fulfill short-term power needs, as long-duration storage already requires substantial discharge power-capacity to meet long-term power needs, such as large demand spikes during weather events.
2. Among all storage portfolios we analyzed for systems with abundant solar and wind energy, systems deploying underground hydrogen storage or metal-air batteries had the lowest total system costs, due to being the most cost-effective long-duration energy storage technology. This is because they had the lowest energy-capacity costs out of all storage technologies modeled (~2 $/kWh energy-capacity cost for hydrogen, and 20 $/kWh total cost and 100-h duration for metal-air batteries).

Methodology

Modeling of Different Storage Technologies

We modeled various low-carbon energy storage technologies currently available on the market:

• - 🔋 Lithium-ion batteries
• - 🧪 Redox flow batteries
• - 💦 Pumped hydro storage
• - 🏗️ Gravity energy storage
• - 🔥 Thermal energy storage
• - 💨 Compressed air energy storage
• - 🤘 Metal-air batteries
• - ⚗️ Underground hydrogen energy storage

In our model, we select base-case costs and round-trip efficiencies from the middle range of estimates from other techno-economic analyses.

Ranges of total installed energy- and power-capacity costs of different low-carbon energy storage technologies on the market

Modeling of Different Geographic Regions

System costs for combinations of storage technologies in CONUS

System costs for combinations of storage technologies in CAISO

System costs for combinations of storage technologies in ERCOT

System costs for combinations of storage technologies in ISO-NE

System costs for combinations of storage technologies in MISO

We then simulated the deployment of different combinations of storage technologies in solar- and wind-based electricity systems, representing several geographically diverse regions:

1. The Continental U.S. (CONUS)
2. California Independent System Operator (CAISO)
3. Electric Reliability Council of Texas (ERCOT)
4. ISO New England (ISO-NE)
5. Midcontinent Independent System Operator (MISO)

Acknowledgements

I couldn’t have done this without my collaborators from the Climate Energy Lab at the Carnegie Institution for Science, especially my co-first authors (Edgar Virgüez and Jackie Dowling). I started this project during my junior year at Caltech with Jackie, who was my graduate student mentor at the time. I’ve learned and grown so much as a researcher throughout the process, and I want to give an extra special thanks to Jackie for giving me the hands-on and supportive mentorship that I needed to get started in the macro-scale energy modeling world. I also want to thank Edgar Virgüez, Ph.D. for putting in countless hours to push this paper through submission and reviews to the finish line.

I also want to thank my other co-authors, Alicia Wongel, Dominic Covelli, Tyler Ruggles, and Natasha Reich, for their huge contributions towards this study, especially during the review process. Additionally, I owe a special thanks to my advisors Ken Caldeira from Carnegie Science and Nate Lewis from Caltech for providing the environment that greatly contributed to my development as a researcher.