A new era for gravity energy storage?
Explore with us how Eric Chaves, founder of Terrament unveils how his idea on gravity storage came to be
Fellow Explorationist ¿Cómo estás?
The International Energy Agency (IEA) has recently updated their forecast for annual global growth of wind and solar capacity for the next coming years (until 2025). In their report (May 2021), IEA now perceives even a higher renewable contribution than what they estimated a year earlier. This forecast comes with a challenge. The massive growth in renewables must also be matched by grid improvements (i.e smart grid. demand/response AI + Analytics) and large energy storage capacity.
Many critics of the renewable industry often argue that the intermittency of solar power and the variability of wind energy hinder the capacity of these resources to replace the way we currently produce power (mostly via fossil fuels). In the words of Josiah Neeley, “such an argument involves what philosophers call the fallacy of composition. Just because something is a feature of a whole system does not mean that it has to be a feature of each of the system’s parts. It is important for electric reliability that the grid as a whole can provide enough generation to meet demand at all times. It is not important, however, whether any individual plant or group of plants are able to do so”.
Intermittency is solved with energy storage and smart grid solutions. In order to enable the needed scale up of more and more renewables into the grid, innovation will be critical to solve the large scale energy storage conundrum. Energy storage is indeed as important as the solar panels and turbines are for the decarbonisation of the entire power, heating and transportation sector.
Although people often think of energy storage as a battery that uses a chemical reaction to release energy in the form of electricity; reality is that chemical storage is just one type within a wider storage spectrum. There are many other ways to store energy for later use, fossil fuels are the incumbents right now, but also hydroelectric dams and pumped-hydro that store potential energy in water reservoirs and releasing it by dropping it and passing it through turbines.
Over the last decade, chemical energy storage has had great improvements in efficiency and capacity, lithium-ion batteries are currently in the spotlight of energy storage technology, accounting for 80% of energy storage VC funding, but the energy storage landscape is bigger than the Teslas and the NIOs. Chemical batteries are a form of short-term storage and so far they are applicable at the household level and in short haul transportation. We need a form of longer term and larger scale energy storage that can leverage the surplus of renewable energy created at peak times.
There are a lot of startups working in the energy storage space, this map from our friends at Contrarian Ventures shows a comprehensive market map.
The spectrum in gravity energy storage is small. Some notable examples are:
Energy Vault that is storing energy by using an automated group of cranes that lift and drop heavy blocks;
Gravitricity is building a system with cables that lift weights from mine shafts and;
New Energy Let’s Go, who acquired the patent of Heindl Energy GmbH (recently bankrupted) that uses hydraulic power to lift masses of rock.
However a new crop of players is coming to the scene. Terrament is a startup that is tweaking existing technologies to develop an innovative approach using potential energy stored at height, taking advantage of gravity, wind turbines and mining tech. We had the pleasure to interview Eric Chaves, the founder of Terrament in our ClimateTech Talks podcast (link below) to discuss his upcoming techno-commercial plans, and the future of energy storage. Enjoy the conversation.
Also, if you missed our interview with Contrarian Managing Director, Rokas Peciulaitis, why don’t give it a listen as well.
(This interview has been edited for clarity and length purposes).
Hi Eric, could you tell us who you are and what you are doing?
Hi! I started off in engineering in college, but my career path took a lot of different turns and eventually landed me working on Terrament, starting a few years ago after researching climate change.
So, you know, from my beginning studying engineering in college, I was always looking for the design side of things, the entrepreneurial side. I found architecture as something I was really interested in, so I ended up majoring in that, working in it for two years, then shifted to industrial design, which I realized was really the path I was looking for, while doing engineering.
Then the recession in 2009 pushed me to software. I've been doing that ever since up until Terrament. So, really kind of all over the place, I also started a tech startup along the way there, so I had some entrepreneurial experience. Then when I was researching climate change I felt that I really wanted to work in this space and contribute to it, figure out what I could do. Energy storage quickly became a topic that I was really fascinated by and felt like I had some ideas to contribute. The last part of that story really is about how all of the storage we have in our grid is basically all pumped hydro – about 95% of it. And we only have a tiny amount, only about 3% of all of the energy in our grid, that ever goes through storage.
We have to build about five times the amount of energy storage that we have today to solve our climate crisis by 2050.
Do you mean in the US right?
In the US, but it's pretty similar worldwide as well. The averages worldwide are about the same. When I was considering the problem with pumped hydro, it's a great solution, but we can't really build very much more of it, but we have to build about five times the amount of storage that we have today to solve our climate crisis by 2050, because we have to support wind and solar, which are intermittent sources.
In order to solve this, we really need a new solution that's as cheap as pumped hydro. And lithium-ion (batteries) for a lot of reasons, experts just don't believe that (batteries) are going to be able to solve that. It'll be great for mobility and things, but we need a new large-scale solution.
And when I was thinking about how we can replace pumped hydro, you know, the problem is really just height and weight. It's basically gravity storage. So I was thinking, well, what if we dig deep underground? And I was actually surprised to find that it was totally feasible. The mining industry has figured out a lot of that technology. And I found research from the United States government in the 80s exploring underground pumped hydro, and then Terrament evolved from there. What we're building is solid mass, modular gravity storage that we deploy deep underground in mine shafts. That was the evolution.
I'm from a geological background and it seems like a great innovation in this space.
Thanks. It's been really exciting to talk with folks like you who do have an understanding of that and expertise and a lot of mining experts are really excited about this, and also it could be a way to reskill, or not even to reskill, but to have people who already have the skill of mining and digging underground, to be able to work on climate friendly solutions, like what we're doing instead of oil and gas solutions as those get phased-out.
That's a big concern of a lot of people from the energy industry. People like me and other folks from the sector are looking for other ways to contribute to the energy space and also fight climate change.
How big is the team right now?
The official team is just me really, but we have a great team of advisors right now, I have two summer interns. I'm working with consultants like a grant writing consultant. I am working really hard right now to figure out the co-founder team. It's a really exciting time, especially having the interns to support the project and figuring out how this team is going to shape out.
I read on Climate Base that you are also looking for a CEO
For a co-founder potentially or a potential first hire. I've had really amazing people respond to that already. It's been better than I could have expected. It's been amazing to talk with these people who have just amazing experiences and qualifications and super motivated and kind people. So I'm really excited about that.
What kind of profile are you looking for?
I'm looking for a senior level engineer. Mechanical and electrical are the two that I'm especially looking at, also civil. And you know, we are still pre-funding. We're also actively talking to many investors and we're hoping to close an angel round between $250k and $1m. That will also help support that team. We're right in the middle of that chicken and egg problem, getting it all figured out at once right now.
Are you also considering crowdfunding platforms?
Very much so. I'm trying to figure out how a lead investor will support me through that. A lead investor can lead that round and have other investors fall into the platform. I think it's simplified a lot of that process and there's really great platforms that don't even take that much, if any, of a fee on top of it. So to me so far, it seems like a win-win situation and I'd be really excited to do it.
Coming back to the technical side of things, do you have any technical challenges that you have to overcome to be able to build this underground facility?
So many challenges. It's such an audaciously large, huge thing to build. It really is, you know, a massive size. So the things we have going for us is that we're not inventing any new novel technologies. We don't have to do a decade of research or more before this becomes feasible. We're really taking existing technology like mining and using large mechanical gearing systems already used with large wind turbines. It's really about synthesizing a design and bringing those components together. But even though there's nothing new here, there's nothing novel besides the design and the synthesis, there's going to be so many challenges.
Digging is really complicated, finding the right bedrock conditions. But all of those challenges are figured out by different experts in the system. So my job really is to pull together these experts and to call upon all the knowledge that we already have and then convince investors that this is so important and the numbers look so good – it looks like the cost could be so low with the system – that it really is worth investing in the early prototypes. And then the first installations for this technology.
I was just wondering how big the facility would be? And how much energy would it produce?
We can build smaller, but really the key, what makes this design so exciting is that we can build at scale as possible to dig down a mile underground or deeper even. And so really the best costs come at scale. And the scale that we're targeting would be about the same order of a large hydro facility. And what that looks like is about 2GWh of storage.
It would cost about $400 million and the sizing would be about a mile deep, maybe a six-meter diameter. And that would be filled with large, heavy massive modules that have a large wind turbine generator inside of them. That acts as the motor generator to both lift the modules up on a geared track that would be bolted into the bedrock and then to use basically like regenerative braking as these fall down the shaft. So it's similar to pumped hydro, you have a turbine that spins as water pours down the shaft and you use that turbine to pump the water back.
So above the surface you wouldn't take up that much space
Yeah, that's right. So the way this works is we have a mile deep and you also have a mile-long track above ground. In an ideal scenario, we could even cover that with solar panels so the real estate could be almost nothing. And then the research that we're doing, it does look like if you co-locate this with a solar facility, then the real estate costs could be very minimal.
But you know, we do need to find a location where there's that opportunity to have a mile-long track above ground, or we'd have to bury it, which would be very feasible, but would add more expense.
Have you talked with solar providers to pitch them this idea?
Yeah. We've talked to a couple of energy developers. We want to talk to a lot more, you know, right now in the phase we're at, we're trying to prioritize as much as possible. We have a million things. And so there's so many things that we've been excited to do that we haven’t done, but we have talked to at least two energy developers and one of my favourite things about this idea is that everyone loves it. Everyone thinks that it's really brilliant if it works. We need this, there's no doubt that we need this solution.
The energy developers are very excited about it. Obviously we're so early, we have so much to prove, but they're helping us figure out what the data is that we have to show them so that they'll feel comfortable, help moving forward with us and consider building it.
And what do you think you need to make or build to prove that to them? Something like a small-scale facility?
Exactly. So right now we're building a very small scale prototype just in the office. Just to kind of show us the basic mechanics, but really the first step is to build a 1:10 scale prototype. It doesn't need to have the full height of a one 10th scale. So we're actually looking at about a 100-foot shaft, one-meter diameter, something in that order of magnitude. And we have great potential engineering partners that we're talking to. There's some non-profit engineering companies out there that will help us apply for grant funding.
And then that grant funding will pay for their expertise to help us build these prototypes. And so we found some exciting potential partners with that, and they would be able to give us all the extra expertise and facilities that we would need to build this.
Awesome. Let's connect the dots with the funding. What would be your next step after raising the funds?
The angel round will give us about a two-year runway and we want to augment that with grant funding. So we're also applying for a lot of grant funding. We're in the middle of two federal grant applications and a number of others and there's exciting opportunities coming out all the time right now. We have a really great consultant who's helping us track those and apply to as many as possible. For example, the prototype we hope will be paid for entirely by grant funding. The angel investment that we are raising, will just supply our basic needs to have some engineers do some design work, paying consultants and things like that to keep us going for a couple of years while we keep applying for the grant funding.
So my idea is that we can build this as fast as possible because we all know that it's really, really urgent and to experiment with all these technologies as fast as possible.
I was reading on your webpage that you have a patent pending, right? Is that holding you back in something?
Yeah, great question. I don't think so. The patent process has been really interesting. That was pretty new for me. I was involved with one a long time ago, but it's new. We just filed, we filed the provisional over a year ago and we just filed a non-provisional. So now we wait to hear back for feedback and; I think right now it'll be a while anyways, until we know how that stands. So right now, I think it's just helpful knowing that we have that in the process.
If it wasn't for the climate crisis that was making this so important, I certainly wouldn't be motivated to do this startup without that. You know, as a purely money making scheme, like this is not about making money. I do believe that it will be incredibly valuable.
So, what are the main barriers you've found? Besides the technical challenges. Is there something else holding you back? Maybe the investors may be just thinking “I'll just wait for Terrament to grow a bit more before investing”.
I think that the financing, the investing part is a huge barrier. It's such an enormous scale that we're working at and the payoff will take a really long time.
So if it wasn't for the climate crisis that was making this so important, I certainly wouldn't be motivated to do this startup without that. You know, as a purely money making scheme, like this is not about making money. I do believe that it will be incredibly valuable.
I think it's a really incredible opportunity to make a lot of money, but the payoff takes us such a long time that we have to find that rare investor who both cares about the climate and is technical enough to understand the huge opportunity that we can do with this. And to be patient, to wait that long and as far as I understand with the investing landscape and companies in general, that's a really hard ask.
I think you also mentioned that you are also considering building an underground pumped hydro, Am I right?
So I wouldn't say it that way, because we don't have any immediate plans or anything, but what I think is really interesting, I said that I got started on this by researching underground pumped hydro. And actually on our website, there's a tab, it says research and there's a white paper that I wrote that was just uncovering that research. And so I still think that underground pumped hydro is an exciting opportunity and it's really feasible. It could possibly be just as good as the Terrament design that we're looking at. You know, maybe better. We're not sure.
So it's not out of the question that Terrament could focus on that in the future, but really I decided to pivot to what we're doing now. Because I think it's more unexplored. I think there's more that we can contribute. There's more possibility that we haven't discovered yet, and I felt like it would be much easier to launch the startup using that approach.
And are there other gravity solutions on energy storage out there?
Yeah, so it's a really interesting landscape. I think that there's such a large need and I think there's a lot of room for differentiation in the landscape. I think that all of the startups doing similar things are helping each other to kind of show that there's a larger place for gravity storage. To name a couple, there's one called Energy Vault, which is probably the most known, and that has a tower above ground that uses a crane to lift a series of blocks to a larger tower or a smaller one. And the energy is produced through a motor at the top of the crane. And then there's another one called Gravitricity based in Edinburgh believe, that also is digging a shaft underground. And they are using a winch-like device as well to hang a cable and have a piston of weight to lift that up. Both of those have their first prototypes, which is really exciting.
Both companies are demonstrating in the real world that this really does work and that the numbers really do come out as they've been estimating. Just to say a word on how we're different. Our selling point is really that we're able to reach a different kind of large scale because we're maximizing the two simple ingredients of energy storage, which are height and weight. With the former, we're getting 10 times more height than, for example, Energy Vault has above ground. What's really interesting is that just because we're stacking all of those modules into one large height, it means that we get 10x the storage that Energy Vault has with the same height and weight.
Then compared to something like Gravitricity, they're on a smaller scale, probably, which is I think ultimately going to be a different niche area than what we're looking at. And a way to see why is that they wouldn't be able to support all of the weight that we can in an underground shaft, because a cable can't support that much weight over a large distance. Our solution, the unique part of what we're doing, is that each module supports its own weight with a gearing mechanism that is geared directly to the bedrock itself through racks that are bolted in.
What happens if a gear gets stuck?
We have designs and ideas that we don't even publicize on the website. I'm talking to engineers constantly, brainstorming about that. I like to tell investors ‘don't worry, this is really early.’ There's a million ways to design around. For example, we are already designing in cases where a module gets stuck or if it needs repair, It'll be able to be lifted by one of its sibling modules, and then it can be repaired above ground.
A module will always have some kind of a safety mechanism; if the power cuts it'll brace itself against the shaft wall We have different gearing mechanisms that we're playing with, which are not shown on the website to address things like getting more surface area of contact with the gearing between the shaft walls or allowing for better gear tolerance, for example, things like that.
I know that's a big issue in the wind industry with the wearing of the gears of the wind turbines. So, I guess that you will also run into this kind of problem.
Yeah. And you know, like looking at our O&M costs, for example, in our cost estimates we're trying to compare things like looking at the wind turbine repair costs as well, and some other metrics. Those will definitely be factors and that's all factored into our costs.
Well, it's been great, Eric. I think that Terrament is an amazing solution and I'm looking forward to knowing more about you and I'm really hoping that you find this angel investor.
Thanks so much, Daniel. It's really great to talk with you.
Our recommended reading for this week:
Though we can argue that Climate Change is a scientific consensus and not a belief system, this argument from Pitchbook.com on Why investors are raising climate tech funds at a torrid pace resonates with us: “Even if you don’t believe in climate change, you cannot dispute the economic argument for deploying renewables”
If you are into communicating climate change issues, check out this amazing resource from the Centre of Research on Environmental Decisions (CRED): The Psychology of Climate Change Communication
Finally, our friends of Silicon Valley Bank have put together a great report in the state of Climate Tech in 2021. Check it out! : Link here.
If you want to send us an idea or a tip, a #ClimateTech company that we should have a look at, or if you have any questions, please reach us at: davidcongeof@gmail.com or arraiz.p.daniel@gmail.com.
Some of the music we’ve been listening: