Terrament: solving our trillion-dollar energy storage crisis

  • Terrament is building affordable, scalable energy storage using a technology called Underground Pumped Hydro Storage, or UPHS. UPHS is a well-researched, low-risk technology. We estimate that our design will be 3-15 times cheaper than lithium ion storage over a lifetime of forty years.

    Learn more at Terramenthq.com

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    UPHS design from a U.S. DOE report. See website for details.

  • @Eric-Chaves how limited is this technology by the physical geology/geography of the location?

  • @capilano Hey, great question. This is one of the huge advantages of bored-tunnel UPHS: The lower reservoir is mined out of bedrock deep underground. So we can build it just about anywhere with suitable bedrock conditions (most of the US). And we don't depend on any natural elevation changes above ground unlike other pumped storage designs. Additionally, because the hydraulic head height is so large (about 1km), the reservoir volume per MW is greatly reduced.

  • This is really cool. Wasn't familiar with PSH (https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity).

    My first thought was actually scaling it down. Looking into pico hydro now (https://en.wikipedia.org/wiki/Pico_hydro).

  • @Eric-Chaves seeing as how energy storage is so critical to getting more clean energy on the grid, I commend your efforts with Terrament.

    I've seen underwater pumped hydro storage before like this company. What pros and cons exist with underwater vs underground energy storage?

  • @velodrone Thanks! I just found hydrostor.ca myself. I'm trying to reach out to them as I'd love to collaborate and learn from them. They use pumped hydro along with CAES - compressed air storage. CAES normally requires a fossil-fuel like propane to make their system efficient. Hydrostor found a way to avoid using fossil-fuel, but I belive it comes at an efficiency cost. Their system is only 65% efficient. Terrament, like other pumped hydro, is around 80-90% efficient. We hope to get even more efficient than that with innovative design, but we're not ready to talk about it yet 🙂

  • @Eric-Chaves I'm quite familiar with Hydrostor as I've met several of the team members! Their pilot project with Toronto Hydro is really interesting. Time shifting energy demand with storage provides a lot of benefits to the grid

  • @max what have you found in the world of pico hydro?

  • @ericvanular Oh very cool that you know Hydrostor! Wow, is this the Toronto project you're talking about where they use underwater balloons offshore? That's interesting that it's such a different solution to what they're doing now.

  • @Eric-Chaves Indeed it is! They are definitely doing some interesting work, it may have pivoted slightly. I'll see what can be done to engage them here

  • @Eric-Chaves Are you able to share what makes Terrament's technology so much cheaper than lithium-ion? Battery cost curves seem like they're coming down quickly - will this cost advantage last?

  • Hi @Rob-Bennett, thanks for the question! Yes indeed. I wrote a UPHS feasibility study to examine this question in detail which you can find here. https://www.terramenthq.com/underground-pumped-hydroelectric-storage-feasibility-study.pdf Specifically, there is a lot of info in this appendix section (16.8 Comparison of researched LCOE for PHS, UPHS, and Li-ion Batteries)

    Here's a summary:
    Today, PHS in general is currently far cheaper than Li-ion - about 6 times cheaper. Li-ion is indeed expected to drop in price and our calculations take that into account. Even with Li-ion dropping in price, PHS/UPHS will still be cheaper than Li-ion over the next 40 years.

    Even if we compare a conservative UPHS estimate to an optimistic Li-ion estimate, UPHS is still cheaper. Whereas An optimistic UPHS estimate could be vastly cheaper. UPHS is actually comprised of very well understood technologies so there is little risk. On the other hand, we've never built Li-ion at grid scale. There are significant risks which could dampen the optimistic cost drops in Li-ion.

    All this is to say: We should still invest in Li-ion of course. But we need to develop everything in our arsenal to address the climate crisis. So it's crazy that we're not already developing UPHS given how much promise it holds. Terrament is going to change this and build it as fast as possible.

  • @Eric-Chaves said in Terrament: solving our trillion-dollar energy storage crisis:


    Really in-depth study here - you've obviously put quite a lot of effort into this so thank you for sharing. Sounds like promising energy storage tech, what major obstacles are you encountering so far?

  • Thanks @Pascal-Ramsey! Yes, I after discovering research on UPHS showing that it could be highly feasible, I spent much of the summer working on that feasibility study to summarize and contextualize my findings.

    Terrament's biggest obstacle at the moment is getting funding. But we're working with civil engineers to flesh out our designs and strengthen our case so we can pitch funders in earnest. We're really just getting started.

    As far as major obstacles for UPHS in general... The only big obstacle is finding the right partner willing to make a massive, long term, profitable investment. This partner could be a municipality, a Transmission System Operator, a cooperative pool of power generators, or some other entity.

    UPHS doesn't use any new technology. Everything from the tunnel boring to the hydro mechanics is very well understood stuff. So govs and power industry folks just need to think big, understand this math, and start building this as fast as possible. We need a lot of Li-ion batteries also, but swapping in UPHS for some of largest bulk storage could save us trillions of dollars on our impending energy storage crisis.