How Carbon Removal Offtakes Are Starting to Unlock Commercial Debt

Houston-based Vaulted Deep has closed a $35 million debt facility from Italian bank Mediobanca. The loan is supported by waste-service agreements and contracted carbon removal revenue.

Vaulted calls it the largest publicly disclosed U.S. commercial debt deal in durable carbon removal secured by long-term purchase contracts. The structure matters more than the size.

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What Did Vaulted Deep Secure from Mediobanca?

Vaulted Deep secured a $35 million commercial debt facility from Mediobanca on September 21, 2026. The money will fund new waste disposal sites across the U.S.

CFP Energy arranged the deal. It's a carbon and energy markets specialist with nine offices across Europe. Mediobanca is a Milan-based investment bank.

Vaulted builds underground disposal infrastructure for organic waste. It turns biosolids, manure, and paper sludge into a slurry. Then it injects that slurry thousands of feet underground using proven oil and gas well technology.

Two revenue streams supported the loan. The first is waste-service agreements with waste producers who need disposal capacity. The second is contracted carbon removal revenue, including offtakes with Frontier buyers.

Carbon offtakes alone did not secure the facility. The waste business carried part of the weight.

How Do Carbon Removal Offtakes Help Secure Commercial Debt?

Long-term offtakes turn future carbon removal deliveries into contracted revenue that lenders can model. That predictability lowers the risk of lending money for new infrastructure.

Frontier is an advance market commitment backed by Stripe, Shopify, Google, and other companies. It facilitates purchase agreements where suppliers get paid when tons are removed.

Frontier buyers signed a $58.3 million offtake with Vaulted in May 2024. The deal covers 152,480 tons of CO₂ removal from 2024 to 2027. Vaulted delivered its first tonnes to Frontier buyers within about four months.

Frontier reported over $713 million in offtakes covering 1,886,898 tons of contracted removals in December 2025, according to ESG Dive. It also backs NULIFE GreenTech's biowaste approach in Canada and CREW Carbon's wastewater system.

Here's the financing logic in five steps:

1. Contracts: Multi-year purchase deals set price and volume.
2. Predictable revenue: Payments arrive as verified tons are delivered.
3. Reduced lender risk: Future cash flows can be forecast and stress-tested.
4. Access to debt: Lenders can offer capital without taking ownership.
5. Faster deployment: New sites get built sooner.

Frontier spokesperson Hannah Bebbington Valori said the deal puts Frontier's theory of change into practice. Large, multi-year demand is meant to help suppliers raise building capital.

Waste-service agreements add a second layer of predictable income. Together, the two streams gave lenders more than one source of repayment.

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Why Does Moving from Equity to Debt Matter?

Debt lets Vaulted Deep grow without giving up more ownership. The $35 million facility adds to about $48 million in equity and an $8 million XPRIZE Carbon Removal award.

Equity investors accept high risk in exchange for upside. Lenders want steady repayment. They commit when future cash flows look reliable.

Many carbon removal startups still lean on venture rounds, grants, prizes, and advance purchases. Commercial debt sends a different signal. A lender was willing to back contracted revenue.

Date	Capital or Contract	Amount	Type
May 2024	Frontier buyers offtake	$58.3 million for 152,480 tons	Contracted revenue
November 2024	Series A led by Prelude Ventures	$32.3 million	Equity
2025	XPRIZE Carbon Removal award	$8 million	Prize
July 2025	Microsoft 15-year agreement	4.9 million tons	Contracted revenue
September 2026	Mediobanca facility via CFP Energy	$35 million	Commercial debt

CNBC described the Microsoft agreement as one of the largest removal contracts globally. Vaulted's roughly $48 million in equity now works alongside borrowed capital.

Durable storage is growing in the wider market too. IEA CCUS project data counts more than 50 million tonnes of capture and storage capacity in operation.

What Role Did Artio Play in De-Risking the Deal?

Artio, a London-based carbon insurance firm, helped de-risk the Vaulted transaction. It's part of Artio's wider work to unlock capital for high-quality carbon projects.

Artio earned Lloyd's coverholder status in 2025. Insurers Tokio Marine HCC, Markel, and Apollo provide its insurance capacity.

Artio's cover targets the risk of carbon credits being under-delivered. Carbon insurance is moving into mainstream finance as removal market spending passed $1 billion in 2025, according to Sylvera.

Risk-transfer tools could matter more as projects seek conventional financing. Growth in permitted underground storage helps too, as America's carbon storage map expands state by state.

How Is Vaulted Deep Scaling Its Operations?

Vaulted Deep delivered more than 20,000 tons of carbon removal to Frontier buyers in the first half of 2026. That six-month figure topped its full 2025 total.

Weekly waste volumes have climbed sixfold since 2023. The company now has an operating track record alongside its contracts.

Its Great Plains site in Hutchinson, Kansas, repurposes historic salt caverns. It has processed 226,000 tons of biosolids and excess manure since 2023, according to Vaulted.

Vaulted also works with partner Advantek at Terminal Island in Los Angeles. That site stores about 20% of the city's biosolids underground.

Part of the new capital supports Vaulted's AI-Accelerated Site Development Platform. It uses geology, regulatory, and waste-supply data to narrow site searches and speed permitting. It's one more way geologic storage is getting faster to deploy.

Where Carbon Removal Finance Goes from Here

Vaulted's $35 million facility is one company's deal, not an industry-wide shift. Still, it gives contracted, operating carbon removal businesses a working template.

Debt fits best where delivery records and steady cash flow already exist. Other developers are building that base too, such as the 120,000-tonne BECCS offtake with Wild Assets.

Contracts first, then lenders. Vaulted Deep's September 2026 deal is a working example of that sequence in U.S. durable carbon removal.

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