Understanding carbon capture and storage in the built world
Shelter is one of our most primal needs, at the very foundation of Maslow’s famous hierarchy pyramid. So perhaps it should come as no surprise that the use and creation of our buildings account for a whopping ~40% of global greenhouse gas (GHG) emissions. So, figuring out how to build and power our shelter in a decarbonized way is one of the most pivotal aspects of achieving a climate-safe world.
The good news? We already have a significant amount of the technology we need for this dramatic transformation. Heat pumps and renewable energy sources can allow, in many cases, electrified buildings powered in a climate-friendly way. Efficiency measures can ensure buildings are less expensive to power, more comfortable, and more climate friendly. And tangible progress has been made — for example, in the EU, thanks to national building code efficiency requirements, new buildings today consume 50% less energy compared to typical buildings from the 1980s.
The bad news? Buildings and construction are not on track to achieve 2050 decarbonisation goals — and that gap between goals and reality is widening (UN). And we do still lack key scaled technology to decarbonize energy-intensive building materials like concrete and steel. Additionally, a range of regulatory, market, and structural barriers stand in the way and complicate this transformation.
At Pi Labs we have endeavoured to invest in VC-backable decarbonization at every step of the built world journey — from reducing emissions during construction (Qflow), to choosing building materials with low GHG emissions (Tangible, Responsibly), to increasing efficiency through building energy and resource management (Demand Logic), to monitoring building GHG emissions (Airmo), to reporting on these findings (Omnevue). But there is much more to do.
The next stage is investing in the intersection of CO2 removal, CO2 storage, and the built world. Although many climate activists (understandably) view CDR (carbon dioxide removal) with suspicion, concerned that it will encourage reckless emissions as well as its tendency to be frequently funded by petroleum giants, the truth is there is no way to limit warming to 1.5°C or 2°C without scaled CDR, in conjunction with deep cuts in emissions. CDR is yet another important tool in the wider toolbox of solutions that must all be invested in and deployed in order to tackle the imperative challenge of decarbonization.
CDR involves both the capture of CO2 from the atmosphere and its permanent, durable storage. A bevy of ventures are tackling this intersection of CDR and the built world. Below are three broad areas we see at this particular intersection — we welcome feedback!
(And many thanks to cdr.fyi’s fantastic Carbon Removal Map, a particularly helpful resource for understanding this space)
1. Industry of the future: Direct Air Capture and Storage (DAC+S)
Some ventures are focused on building the infrastructure and scale required to make CDR a standalone industry of the future — as plants / factories today produce energy and other goods, this future likewise imagines carbon removal plants. This is a bet on standalone carbon removal as an industry — requiring buildings and infrastructure and therefore very much overlapping with the built world.
These growing ‘factories’ usually incorporate direct air capture (DAC), which refers to capturing CO2 directly from the air, processing it, and injecting it somewhere for permanent storage (often underground where CO2 can permanently mineralize as a part of natural, albeit artificially sped-up, geologic processes).
This has become a very crowded space. Some of the largest companies include 1PointFive, Climeworks, Carbfix, Global Thermostat, Mission Zero Technologies, and 44.01. Innovation is still required on (i) gaining access to enough air to capture meaningful amounts of CO2 (usually requires fans to blow enough); (ii) the separation process of CO2 from the air (often a substrate that provides a chemical reaction); (iii) processing the CO2 / extracting from the substrate / capture mechanism; (iv) transporting and storing the CO2 once extracted; and (v) powering this whole process entirely with renewable energy, which is still intermittent in many locations without more long-term storage solutions and grids still reliant on fossil fuels. Decreasing costs across each of these steps is pivotal to achieving scale and many other smaller companies are working on innovations across the lifecycle to do just that.
These business models assume demand for carbon removal credits will grow substantially and that, either due to regulatory pressures or citizen / consumer sentiments, governments and companies will prioritize spending to neutralize remaining carbon emissions after other feasible decarbonization methods.
Although incredibly far away from reaching this level of scale, theoretically DAC+S could someday draw down even historical emissions, not just present-day, potentially offering a way to someday reset the climate. (Microsoft, for example, has committed to offset all GHG emissions since their founding by 2050)
Removing all historical extra emissions, however, is incredibly far off and very likely will not be technologically and economically feasible — to anchor the sense of scale, since the year 1850, humans have emitted 2,400 gigatons of CO2 (1 gigaton = 1 billion tonnes) and continue to emit an additional ~37 gigatons every year. Global CDR+S has only reached about 0.045 gigatons annual removal capacity, or just 0.12% of mere annual emissions. As the adage goes, we must hope for the best but prepare for the worst. The road is still very long.
2. Industry integration
Many other companies are investigating ways to integrate CDR within industrial processes — both by (i) capturing CO2 created within industrial process and by (ii) utilizing it within industry in ways that permanently remove it from the atmosphere. Collecting CO2 from ‘point sources’ within industry can be a much more efficient, and therefore less expensive, way to gather CO2 than collecting it from dispersed air.
This integration into physical industrial processes also generally means some installation and building retrofit, directly intersecting with the built world.
Companies often capture CO2 from point sources and / or provide technology to transform the CO2 into carbon-negative chemicals (e.g., baking soda and hydrochloric acid), chemical feedstocks, or other materials. Example companies include CarbonFree, Aker Carbon Capture, Carbon Clean, LanzaTech, ViridiCO2, Aircapture, and Carbon To Stone.
Because these business models enable new materials generation or feedstock material, they can sometimes even save money for industrial processors who incorporate them, enabling a business model that can be both spurred on by regulatory / public sentiments decarbonization requirements but further incentivized through cost-effectiveness.
It is imperative, however, in cases where CO2 is used as a feedstock, to conduct thorough process / product lifecycle analyses to ensure that, once the CO2 is converted, the molecules do not eventually end up back in the atmosphere as CO2, making the whole process moot.
3. Building & building material capture and storage integration
Perhaps the most obvious intersection between carbon and the built world — yet seemingly least crowded — is integrating carbon capture and / or storage into building design itself.
Some ventures are utilizing existing building structures to significantly reduce the costs of carbon capture:
· NeoCarbon — retrofits existing cooling towers to perform direct air capture — since DAC requires a lot of air and fans to blow that air, using this existing air circulation already present in buildings can significantly reduce costs. And with millions of existing cooling towers across just Europe, this retrofitting could eventually represent several gigatons of CO2 removed annually.
· Soletair Power — HVAC-integrated CO2 capture that utilizes buildings’ existing ventilation systems (where, again, there are already systems blowing lots of air) to capture carbon. This has the added benefit of increasing well being building occupants, as indoor levels of CO2 tend to be higher than outdoor levels and higher CO2 levels are known to impact cognitive function.
Additionally, many ventures are experimenting with using building materials for storage. This is particularly key given some of the other most-permanent storage solutions, like the geologic solution of injecting CO2 deep into rock layers, can be quite expensive. ‘Embodied carbon reductions’ in buildings themselves can provide an alternative that simultaneously directly reduces buildings’ carbon impact and even making building materials better and stronger.
Similar to underground CO2 injection, this process relies on CO2’s ability to mineralize — meaning it chemically reacts with certain minerals to create carbonates — or in simple terms, CO2 reacts with some rocks to form more rock. And just like a rock (that isn’t exposed to weathering, etc.), the reaction is permanent.
Example companies that are variations on this theme include:
· Carbon Cure — injects CO2 into concrete, mineralizing it
· Ecolocked — incorporates biochar into concrete
· Carbon Built — cures a cement alternative with CO2, mineralizing and storing it
· Neustark — mineralizes CO2 into demolished concrete which is then recycled for building material use in buildings or roads.
· Carbonaide — converts CO2 into solid carbonates that can be added to pre-cast concrete.
· Carbon Upcycling — locks CO2 inside supplementary cementitious materials and reduces the amount of cement needed to produce concrete.
Similar to integrating CDR+S into industry, integrating these processes into buildings can sometimes have effects like better quality materials or air. Ultimately, however, these materials and retrofits still tend to be more expensive than non-carbon alternatives. The business model therefore is based mostly around helping customers achieve buildings sustainability ratings or adhere to regulation.
We would love to hear from you, our readers — what other areas of intersection between the built world and CDR+S did we miss? Are you working on such a solution? We’d love to hear from you — please reach out to us at investment@pilabs.vc.
