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Research and Case Studies

Terrament is building solid-mass, modular gravity storage. But our story starts with water.

Terrament's design was inspired by our research about the history of pumped hydro storage, and more specfically, with the question: Can gravity storage achieve more height by digging deep underground? This question led to a blog post about an old but neglected technology called Underground Pumped Hydro Storage, or UPHS. Over the summer of 2019, my fascination for this technology escalated into a 70 page feasibility study of UPHS.

Although Terrament is not building pumped hydro, this research about UPHS informs much of our solid-mass, underground gravity storage design.

Underground Pumped Hydro Storage

Video collage of technologies related to UPHS

The Feasibility of UPHS

Drawing from US government research, our UPHS white paper explained why the “UPHS concept is technically feasible and economically viable.” Further, we contextualized this past research to demonstrate that building a UHPS installation today would be more feasible than ever due to low interest rates, improved mining technology, and an accelerating demand for large-scale energy storage driven by climate change. We estimated that over a 20-40 year project lifespan, UPHS could be an order of magnitude cheaper than Li-ion battery technology built today.

A UPHS design from a U.S. Gov ReportUPHS design from a U.S. DOE report. See UPHS feasibility study for details.

Terrament and UPHS

Although our long term road map may include UPHS, we do not have any immediate plans to focus on the technology. Instead, we're fully focused on our own solid-mass gravity storage design inspired by both UPHS and other types of gravity storage.

Our Terrament energy storage design gains the height benefits of UPHS while also leveraging the modularity of solid-mass gravity storage. Learn more about our alpha design on our home page.