After securing significant investment in its innovative supplementary cementitious materials (SCMs) as alternatives to Portland cement and fly ash products, Terra CO2 recently began building its future commercial facilities. Aggregates Business America Editor GUY WOODFORD spoke to company CEO Bill Yearsley to learn more about the business’s impressive rise and next steps.
In 2018, Bill Yearsley was semi-retired and enjoying life in Denver, Colorado, after a highly successful 40-plus-year career in the global building materials industry, when, out of the blue, he received an intriguing telephone call.
“I was on the board of a frac-sand company that a big hedge fund had capitalised and one of the hedge fund’s partners, whom I’d become a good acquaintance of, called to say that there was this small Canadian mining company in Vancouver that does project development in the Yukon that had a big mine tailings waste stream problem. They were looking for a solution and had hired a young geologist from the University of British Columbia, Donald John Lake (DJ Lake). He had figured out a way to take mine tailings waste and use it as a cementitious product in an out-of-the-way place in the Yukon. The small company’s CEO realised that this application might have broader appeal than just in the Yukon, and he also knew the same hedge fund partner I did, so he asked him if he knew anyone who could help develop DJ Lake’s solution. The hedge fund partner said he knew someone who had ‘been in construction materials forever’, so I got the call.
“The hedge fund partner asked if I had any interest in this and, if so, he hedge fund could come in as an early start-up partner. I said I wasn’t interested, but he still wanted to email me the information package on this mining company. I made the mistake of reading it over a weekend, and it caught my eye. I phoned back and said, ‘You know what. I’ve got a son working in Seattle. I’ll fly up to Vancouver to see this company, and then go and visit my son afterwards. I said I’ll let you know if I have any brilliant ideas for developing this solution.”
After leasing a hire car in Vancouver, Yearsley drove to the mining company’s registered trading address. “I was trying to find this place, which seemed to be in an old industrial area. I went down something akin to a back alley and saw an open garage door and a guy in a welding apron and hood. Then I saw the mining company’s dust-covered address sign above him. What struck me was not the dusty old garage; I saw a scientist who knew what a welding torch was. I parked and got talking to him.”
Yearsley describes DJ Lake as a “little apprehensive at first”. “We then went to lunch, and I ended up spending two days asking him a lot of questions. He told me he’d worked on his cementitious product from waste solution since around 2016. I was intrigued by how smart this guy was, and also by the fact that he was practical. Following that trip, I contacted the CEO of DJ’s small mining company and offered to work as an advisor for six months, dedicating a few hours a week to help them develop this solution.
“At the end of those six months, I was pretty convinced it was viable, had legs to scale up, and could be meaningful in decarbonising cement. I told the CEO, ‘At my age, time matters.’ I said that his company had to be an American company, with the Canadian company becoming a subsidiary of the U.S. business [now Terra CO2]. That would enable us to raise some real investor capital. In the first funding round, in 2020, I was trying to raise $2-$3 million as the company was operating on fumes. There was not much money in the bank.”
Through a series of mutual acquaintances, Yearsley and his now U.S. small mining company employer were introduced to Breakthrough Energy Ventures (BEV), the Climate Fund of American businessman and philanthropist Bill Gates.
“I met a [BEV] partner, and he thought the cement from waste solution was interesting and thought they may be able to invest $1 million. I thought that was great, as was the company’s association with Bill Gates! The next day, I got a call from this partner who said that one of the senior guys [at BEV] wanted to talk to me. I asked who it was, and he said, ‘It’s the guy who signs Bill Gates’ cheques’. I said, ‘I guess I can make time for that!’ It was a scheduled half-hour evening call, but we ended up staying on for over an hour and a half. The next morning, the partner called up and said, ‘I don’t know what happened last night, but the marching orders I got were we want to invest in Terra CO2, we want to own 30% of the company, and we don’t care how much money they raise.’ We ended up raising $10 million with Breakthrough Energy Ventures leading the funding round. I believe to this day, the [$1 million] cheque that they wrote is still the fastest they ever wrote from an initial meeting: from the handshake introduction to the cheque signing was just three-and-a-half weeks.”
From just two employees at the end of the company’s first funding round in 2020, Greater Denver-based Terra CO2 began scaling its business, moving beyond lab scale and building pilot plants for its first product, OPUS SCM. A BEV-led Series A funding round in 2022 raised another $45 million for the company.
“We have since had a Series B funding round that raised another $125 million. It is likely to raise another $35 million to $40 million, as we have people knocking on the door wanting to join us, so we have kept that funding round open,” explains Yearsley.
In July this year, Aggregates Business reported that the Series B funding from new strategic investors is supporting the build-out of Terra CO2’s future commercial facilities.
In addition to its Series B co-leads, BEV, Eagle Materials, GenZero, and Just Climate, the new funding round included other key industry players. This included major investment from Barclays Climate Ventures, as well as Prologis, Cemex, and Siemens Financial Services, the financing arm of Siemens.
Terra CO2 is establishing a commercial processing facility in the Dallas-Fort Worth market, capable of producing up to 240,000 tonnes per year of its SCM products. The funding will also expand the company’s offices and industrial facilities, as well as develop commercial projects and new cementitious products.
Terra CO2 is utilising local feedstocks from existing aggregate mines and works within existing industry infrastructure. The business’s second product, OPUS Zero, is currently undergoing active concrete trials, and, says Yearsley, will serve as a full replacement for Portland cement.
“We say, ‘Yes, we are a climate company, but we are a construction materials company first’. We aim to create products that people will buy, regardless of whether there is a climate benefit. The fact that Terra’s cementitious materials also offer significant carbon mitigation is an additional advantage for the built environment. It’s the icing on the cake.
“We arrived at 240,000 tonnes per year of SCM products production for the new facility after calculating that the SCM market in the Greater Denver area is around 450,000 to 500,000 tonnes of consumption per year, based on historical SCM company business. So, having a plant that has the potential to capture half of that seemed logical. Dallas-Fort Worth is the largest concrete market in the U.S. You could have four or five plants, like our new one, there. We understand that we won’t be able to capture 100% of the local SCM product market immediately. We will break ground on our Dallas-Fort Worth plant this fall, and it is expected to start operating in early 2027.”
Yearsley has built several businesses on his own, but the core part of his earlier career was his time as CEO and chairman of Redland PLC’s Construction Aggregate Group, leading 12,000 staff across three continents. “I was working in concrete, ready-mix, aggregates, asphalt, asphalt paving, and precast, and we were probably one of the world’s biggest consumers of cement, so I’ve dealt with all the major cement companies.”
With sales of $2.5 billion annually, Redland PLC specialised in concrete roof tiles, aggregates, stone quarrying, road surfacing materials, concrete products, and clay bricks. The company was acquired in 1997 by Lafarge for £1.8 billion. Its roofing division was subsequently sold to the Monier Group, and, since 2017, has been known as BMI Redland, part of the BMI Group (BMI is an abbreviation of Braas Monier and Icopal).
Despite his vast wealth of experience in the building materials world, Yearsley says he believes he has found a “unique” industry colleague in DJ Lake, who is in his mid-thirties and has taken on the role of Terra CO2’s chief science officer. “I’ve never worked with a scientist who is not only brilliant, but also has a lot of common sense. He understands economics. I told him at the beginning we weren’t going to develop anything that wasn’t commercially competitive without Government subsidies. Such subsidies always go away. You need to stand up and grow up as a real business, and I wanted to do that from the beginning.”
Yearsley says that while OPUS SCM and OPUS Zero are “pre-revenue”, Terra CO2 does operate two pilot production plants: a small one at its R&D (research and development) centre in Vancouver, and a larger one in western Denver, close to the famous Coors Brewery.
“We don’t make enough to build an airport runway or a building, but we can make enough SCM to supply a 200 cubic metre concrete project. We also do demonstration concrete pours,” explains Yearsley. “We contributed OPUS SCM to a section of an interstate highway in Minnesota, where it was said to perform great. We supplied part of the concrete for a new Porsche dealership in Houston, Texas, and we also have a project coming up at one of a major global company’s large distribution centres. Generally, we replace anything from 20% to 40% of Portland cement.”
Cement production contributes significantly to global CO₂ emissions, accounting for around 8% of the total. Yearsley notes that the traditional methods for reducing cement’s carbon footprint are evolving. “If you talk to the big public cement companies, around a dozen notable names, a lot will say that the most immediate way to reduce their cement carbon footprint is via engineered SCMs. The waste stream SCMs that we’ve used for the last 40 years, such as those from coal-fired power plants, are being phased out. Steel making is also changing, so furnace slag access is reducing every year.
“A lot of people don’t realise that we’re not only trying to reduce concrete’s carbon footprint. If we don’t replace the waste stream SCMs, you have to use 100% Portland cement, which takes us back 50 years. There is a sense of urgency, not just in companies like ours, but in the industry in general.”
Yearsley says two parts need to be in place for Terra CO2’s OPUS Zero product to achieve the company’s key goal of launching a cost-competitive, net-zero full replacement for Portland cement. “The concrete trials are validating the materials science behind the product, but we also need green energy, including green electricity and hydrogen, at an industrial scale. It is not there yet. For us, it will be a simple conversion to switch our plants from being powered by natural gas to green hydrogen. We are also working on an electric reactor, which will enable us to operate an electric-powered production plant. We want to have it ready so that whenever green electricity is available, say in five years, we will be ready to use it.”
Commenting on the ongoing concrete trials of OPUS Zero, Yearsley says: “Being in industry spec is not the hard part. The hard part is getting your cement, as the binder in concrete, to perform in general use, everyday environments. Portland cement has been around for over a century. It has been an unbelievably successful product. Concrete always gets hard and stays hard with Portland cement. You can pour it in cold weather, pump it up to the tenth floor of a building, and it cures at the right speed, so concrete finishers can use their trowels to achieve the nice finish you want on your concrete. It has all these qualities, which have led to it becoming the dominant binder. So, when you are trying to replace Portland cement, that is what you are up against.
“Our product [OPUS Zero] can reach the specification right now, but can you put it in one of those concrete trucks you see on the highway, and if the job site is an hour and a half away, will it stay fluid? Can you pump it to the tenth floor? How is it under the concrete finisher’s trowel? Can you batch it in a regular concrete ready mix plant? In a couple of months, we are going to start putting OPUS Zero in a concrete pump and a concrete truck and see how far we can transport it, pouring it on very cold days and very hot days, like you get in Houston, Texas, when it gets up to 100 degrees Fahrenheit and 98 per cent humidity. I’m fairly confident it will work in many applications, but I can’t say for certain that it will work in every application. What I can say is that we are doing all the hard work to mimic all those day-to-day-use applications. In two years, we will know a lot more about OPUS Zero’s performance.”
Yearsley says that from 2027, Terra CO2’s major cement producer customers will be licensed to use the company’s standard 240,000 tonnes per year plants to produce OPUS SCM and, in due course, OPUS ZERO, with Terra CO2 getting a royalty from those product sales. This additional SCM production will take place alongside the production of customers’ existing Portland cement-based products.
“The first [Dallas-Fort Worth] plant has already been sold to NSG Logistics, a Texas transport logistics customer that moves a lot of bulk materials. The plant will be housed under its subsidiary, Asher Materials. They are providing the property to house our Dallas-Fort Worth plant.
“Big building materials industry companies, some of whom are Terra CO2 investors, will license one or more of our plants to work alongside either some of their existing cement plants or in one of their aggregate mines, so our plant can use their raw aggregate material. Eagle Materials, one of our big industry investors, has market options on three big U.S. markets. Cemex also invested in our last funding round and has site options for our first entry into Europe. We have ongoing discussions with most of the major cement companies associated with one market or another. We want to ensure that we do a good job taking care of our customers and avoid overextending ourselves. In due course, we plan to manufacture a larger plant than our standard 240,000-tonne plant for some of our larger customers.”
Yearsley stresses that Terra CO2 has a significant advantage in its offerings, as the company can utilise a vast range of silica rock materials from established aggregate mines to produce its SCM products.
“You cannot be successful in manufacturing a building material if you don’t have cheap and abundant raw materials. Limestone is another reason why Portland cement has been successful. You can find limestone in almost every market; it’s not a valuable mineral, like gold, silver or some of the precious metals, and it’s easy to mine. As a carbonate rock, it’s about 10% of the Earth’s crust. We are making our materials from silica rocks, which comprise 90% of the Earth’s crust. I think Terra CO2 is the only company that can work with almost any type of silica rock, including granite, basalt, clays, sand, gravel, and shales from your backyard. That makes sourcing material wherever we want to put a plant cost-competitive and scalable.”
