🌍 Climate

A Startup Claims 90% DAC Efficiency. We Built the Cost Curve That Shows When Carbon Removal Undercuts the Carbon Tax.

Sustaera says its electro-thermal direct air capture process converts 90%+ of input energy into captured CO₂, more than double the roughly 40% ceiling of thermal incumbents like Climeworks and Carbon Engineering. We cross-referenced their efficiency numbers against EU ETS pricing at €74/ton, California's cap-and-trade floor at $28/ton, and the voluntary removal market to build the first crossover timeline for when DAC removal costs drop below compliance market prices.

Viktor Holm

August 1, 2026 · ☕ 9 min read

Nine hundred kilowatt-hours. That is how much energy Sustaera says it takes to pull one metric ton of CO₂ from the atmosphere using its electro-thermal process with nano-structured sorbents and integrated electric heating. Climeworks, the largest operational DAC company in the world, needs approximately 2,000 kWh to do the same job with its thermal approach. Not an incremental improvement. A halving of the energy bill, and in a business where energy is the single largest cost, that rewrites the economics from first principles.

Nobody in carbon removal wants to say this out loud: the entire industry exists in a price gap that makes commercial survival nearly impossible without premium voluntary buyers. Cheapest DAC today costs roughly $600 to $1,000 per ton, while the EU Emissions Trading System, the world's largest compliance carbon market, traded at approximately €74 per ton as of spring 2026, with analyst forecasts averaging €80.61 for the year. California's cap-and-trade settled at $27.94 per ton in its February 2026 auction, barely above the price floor. Every DAC company on earth is selling to voluntary buyers willing to pay a premium for permanence, and if you strip away those buyers the industry collapses overnight.

Sustaera's efficiency claim, if it holds at commercial scale, is the first credible mechanism for closing that gap from the cost side rather than waiting for carbon prices to climb.

Why Energy Efficiency Is the Whole Game

Direct air capture is an energy problem, and nothing else comes close to mattering as much. CO₂ makes up 0.042% of the atmosphere, so extracting it requires pushing enormous volumes of air through sorbent materials that bind CO₂, then applying heat or electricity to release the captured gas for storage, and that release cycle dominates total operating cost because it is where the thermodynamics hit hardest.

Thermal DAC systems, the kind Climeworks runs at its Mammoth plant in Iceland, heat sorbents to 80–120°C using steam or hot water, and maximum theoretical efficiency tops out around 40%, according to Sustaera CTO Cory Sanderson, because most input energy dissipates as waste heat rather than being directed at breaking the CO₂-sorbent bond. Waste heat, in a process where energy is 40–60% of cost. Sustaera's electro-thermal process claims to bypass that ceiling by using nano-structured sorbents paired with integrated electric heating elements that deliver energy directly to the active material.

We translated their efficiency claim into cost-per-ton using current energy prices in three locations where DAC facilities are either operating or planned:

Energy accounts for 40–60% of total DAC operating cost. At the midpoint, Sustaera's efficiency advantage cuts total per-ton cost by roughly 22–33%. Apply that reduction to Climeworks' current reported cost range of $600–$1,000 per ton, and you get $400–$780. Apply it to Carbon Engineering's 2018 theoretical estimate of $94–$232 per ton, and you get $63–$180. Neither number is sub-$100 yet. But neither is impossible, particularly if capital costs are simultaneously 3–5× lower as Sustaera claims. Capital amortization accounts for most of whatever energy doesn't.

When Removal Undercuts Compliance

Carbon market prices and DAC costs are converging. We plotted both trajectories to identify when removing a ton of CO₂ from the air becomes cheaper than the penalty for emitting one. Nobody has published this crossover timeline before.

For the DAC cost curve, we used four anchor points: the American Physical Society's 2011 estimate of $600/ton, Carbon Engineering's 2018 open-book analysis at $94–$232/ton, Climeworks' 2024 operational cost at Mammoth of $600–$1,000/ton, and Sustaera's projected cost trajectory assuming their efficiency and capital cost claims hold. We fitted a learning curve at 15% cost reduction per doubling of cumulative capacity, consistent with analogous industrial chemical processes.

For carbon market prices, we used EU ETS historical data (€5–8/ton in 2017, €25/ton in 2020, €100/ton peak in 2023, €74/ton in 2026) and analyst consensus forecasts from Reuters surveys (€80.61 average for 2026, €93.29 for 2027, ABN AMRO's €100 year-end 2026 target). California's market at $28/ton is structurally different because its price floor mechanism suppresses volatility, but the June 2026 linkage agreement with Washington and Québec will expand the market and may push prices higher.

Results: EU ETS prices cross below DAC removal costs between 2033 and 2038, depending on whether you use Sustaera's optimistic trajectory or the industry-average learning curve. California's crossover is further out, 2040–2045, because prices start so much lower. And the voluntary market for high-permanence removal? Already crossed. Frontier coalition buyers like Microsoft and Stripe currently pay $200–$600/ton. Commercial-scale next-gen DAC will undercut those prices within 3–5 years if Sustaera or a competitor validates their claims.

One number to hold in your head. At $100/ton, removing 1% of global annual CO₂ emissions (370 million tons out of roughly 37 gigatons) costs $37 billion per year, which sounds enormous until you compare it to what the world spends subsidizing fossil fuels annually, which the IMF pegs at $7 trillion including externalities. Half a percent of the subsidy bill.

Scale Is Where Dreams Go to Die

Every DAC cost projection hides a silent assumption: that you can build enough capacity for the learning curve to deliver those cost reductions in the first place, and right now total global DAC capacity is less than 50,000 tons per year. Climeworks' Mammoth plant in Iceland, the world's largest, captures 36,000 tons annually, the equivalent emissions of about 7,800 Americans, which means reaching 1% of global emissions requires a 10,000× increase in installed capacity from where the industry stands today.

Solar power is the closest analogy, having followed a steep learning curve from $76 per watt in 1977 to $0.20 per watt in 2024 over the span of 47 years. But solar had one massive advantage that DAC lacks: each panel generates revenue from day one by producing electricity someone will buy. DAC facilities generate revenue only from carbon credits, and if carbon market prices stay below DAC costs for another decade, the industry could starve before it scales, regardless of efficiency breakthroughs.

An analysis published in ACS Environmental Science & Technology in January 2026 estimated the U.S. technical potential for DAC at approximately 9 gigatons of CO₂ per year, with a substantial portion achievable at less than $300/ton by 2050, provided land, electricity generation, and geologic storage infrastructure are simultaneously developed. That is the largest estimate to date, and it assumes policy support that does not currently exist.

Strongest Counterargument

Sustaera's 90%+ efficiency is self-reported, not peer-reviewed, and not independently verified at any scale, and the company is pre-revenue with cost projections that extrapolate from pilot data rather than commercial results. Climeworks, the market leader, took nine years from its founding in 2009 to its first commercial plant in 2017, and another seven years to reach 36,000 tons of annual capacity at Mammoth in 2024, a facility that still costs $600–$1,000 per ton despite being the most mature DAC operation in existence. Efficiency at the sorbent level does not automatically translate to system-level efficiency at commercial scale, where parasitic loads from fans, pumps, heat exchangers, water management, and CO₂ compression consume energy that bench-scale experiments do not account for. Read Sustaera's announcement honestly: a promising laboratory result from a company that has never sold a ton of carbon removal at any price, competing against an incumbent that has been selling tons for years at costs still an order of magnitude above market. If 90% efficiency were easy, Climeworks and Carbon Engineering would have found it first.

Limitations

Our crossover timeline relies on a 15% learning rate assumption derived from analogous chemical processes. Actual DAC learning rates are unknown because the industry is too young to generate sufficient data. Sustaera's capital cost claim of 3–5× lower than thermal systems is unverified. EU ETS price forecasts are analyst consensus projections, potentially wrong in either direction given the European Commission's proposed ETS overhaul and ongoing geopolitical uncertainty from the Iran conflict. California's $28/ton price may not represent future compliance costs given the June 2026 market linkage with Washington and Québec. Our energy-cost-per-ton calculation assumes continuous operation at nameplate efficiency. Real-world capacity factors for DAC are poorly characterized. Seasonal and environmental variations in humidity, temperature, and CO₂ concentration could significantly affect per-ton costs. We did not model financing costs, which at current interest rates add 20–40% to levelized cost for capital-intensive infrastructure.

The Bottom Line

Carbon removal is stuck between costs that are too high and markets that are too low, and Sustaera's efficiency claim is the first plausible mechanism for closing that gap from the cost side on a timeline that matters, but plausible and proven are different words. Distance between a pilot result and a commercial operation has killed more cleantech companies than bad technology ever did.

If you run a corporate sustainability program: lock in advance purchase agreements for carbon removal credits now. Companies like Microsoft and Stripe pay $200–$600/ton through the Frontier coalition because early commitments fund manufacturing scale that drives costs down. Pay $400 today, get $100 tons in 2035. If you invest in climate tech: watch Sustaera's next funding round. Demand independent verification of both the efficiency and capital cost claims before committing capital. If you vote: push for technology-neutral carbon removal credits in compliance markets. EU ETS does not accept engineered removal credits. That locks DAC out of its largest potential customer base. Until regulators let companies choose between paying the tax and paying for permanent removal, this market cannot function.