Turning Gray into Green

Patricia Halfen Wexler
4 min readMar 21, 2022


Our investment in Chement (pronounced Keh-ment)

Low emissions cement is one of the biggest levers we can move to tackle the climate challenge

Cement makes the modern world possible. By volume, humans consume more cement than water. And since Roman times, most of the beautiful, important and necessary structures we inhabit use cement. Why? Because it does the job and it is very cost effective and durable. However, the process is extraordinarily energy intensive — 2% of all the energy consumed on the planet — 5% of industrial energy — is to make cement.

Cement alone accounts for ~8% of global CO₂ emissions. This is more than all passenger cars! About half come from the chemical reaction itself, and half from the energy intensity of the process. The CO₂ emitted from the chemical reaction can be captured at the point source. Once captured, many technologies exist to sequester or put this CO₂ to good use.

The other half that comes from the very high heat process is harder to remove. If we could re-invent cement-making to require less energy, it would be a boon to society. And if that energy could be renewable electricity (powered by wind, solar, etc.) all the better. Less energy that can be easily electrified solves half of the equation, and much easier capture of the reaction emissions (a concentrated stream of CO₂ vs. point-source from the stack) enabled by Chement’s process solves the other half.

And that’s why we fell in love with Chement.

At Starlight, we are thesis-driven. On the critical topic of climate, we look to back startups developing solutions that will move the most important levers in ways that enable big, viable businesses. Finding scalable, cost-effective alternatives to large, “hard to decarbonize” sectors is essential for humankind. Combined with my undergraduate thesis work at CEMEX exploring viable alternatives to the traditional cement-making process (spoiler alert: nothing could compete with the existing inefficient kilns given the incredibly low price of fossil fuels in Venezuela), cement has been a core focus of ours for a long time. In this case, co-founder and CEO of Sila Nanotechnologies Gene Berdichevsky introduced us to the team. We are also privileged to count on deeply knowledgeable advisors, Gilberto Perez (former CEO of CEMEX USA) and Dr. Hugo Bolio (PhD in cement with decades of experience helping industry improve its technologies) to assess the myriad of proposals being worked on across academia, corporates and the startup world, and support them post-investment.

Chement rose above the others for various reasons:

(a) Their electrochemical approach reduces the actual total energy demands of cement-making by reducing temperature needs. And it could even be used over time in other processes currently using very high-heat kilns,

(b) At scale, their techno-economics pencil out even without unrealistic assumptions for high-priced carbon credits or selling supplementary cementitious materials (SCMs), something all other players need in order to get to a reasonable cost/ton,

(c) Their go-to-market will likely involve partnering with existing cement players, as their process utilizes some of the existing equipment and value chain → avoiding a battle with an entrenched, concentrated, commodity industry with high fixed costs is an imperative to succeed. And last but not least,

(d) The team has deep technical chops and understands the need to work together with industry experts to transform this technology into a company that can help us abate cement emissions within a reasonable timeframe. Co-founders Prof. Venkat Viswanathan and Gregory Houchins impressed us with their visionary proposal, scientific knowledge, and early focus on economic viability and execution.

Chement’s electrochemical approach replaces the traditional fossil fuel-powered kiln heated to >1500⁰C with a metal vat powered by electricity at room temperature. This dramatically reduces energy demand and emissions. And since the gases come out of this process in a highly concentrated stream, the reaction emissions can be much more cheaply captured than with traditional cement production (Already ~4x cheaper per IEA).

How Chement Solves the Problem: (1) Much Less Energy Demand; Easy to Electrify and (2) Much Easier and Cheaper Capture of Chemical Emissions

Our investment, together with funding via ARPA-E and others, will enable Chement to reach kilogram scale and prepare for a pilot plant in a couple of years. We couldn’t be more excited to support them on this journey, and if you have the passion and the skills, they are hiring — reach out here.



Patricia Halfen Wexler

Investor in the foundational companies of a better and more sustainable future @ Avila.VC. Mother of 3. Miami-based and proud Hispanic American