• Deep Sky One received an AAA-A Pre-Issuance Rating from Sylvera, the first assessment of its kind for a direct air capture project.
• The rating evaluates carbon accounting, additionality, permanence and delivery risk before the project begins issuing carbon removal credits.
• The framework gives buyers and investors an independent way to assess DAC projects before making long-term financing and offtake commitments.

Deep Sky has received an AAA-A Pre-Issuance Rating from Sylvera for its planned Deep Sky One direct air capture facility.

It is the first Pre-Issuance Rating Sylvera has issued for a direct air capture project. The assessment follows the development of a framework calibrated specifically to the risks and requirements of DAC.

The rating comes as carbon removal buyers increasingly make investment and offtake decisions years before projects begin issuing credits. For developers, that creates a financing challenge. For buyers, it raises questions about integrity, execution and long-term delivery.

Pre-Issuance Ratings aim to provide an independent view before those commitments are made.

“We’ve already demonstrated at Deep Sky Alpha that we can move from project development to real-world delivery, including issuing North America’s first certified DAC carbon removal credits. This rating means we can bring that same focus on integrity and execution to Deep Sky One before the project is operational, giving buyers and investors an independent view of both the quality of the project and our ability to deliver at scale,” said Charlie Renzoni, Vice President, Carbon Markets at Deep Sky.

Testing DAC integrity before operations begin

Deep Sky One is Deep Sky’s second facility and one of the largest DAC projects currently in development globally.

Its scale gave Sylvera an opportunity to apply the DAC-specific framework to a significant commercial project. The rating also provides a test case for how third-party assessments could support future DAC investment decisions.

“DAC is one of the most important tools we have for addressing legacy emissions, but the market needs a shared standard for what a credible DAC project looks like. Our work with Deep Sky gives the market a real reference point,” said Hugo Lakin, CDR Lead at Sylvera.

Sylvera’s Pre-Issuance Rating assesses three core integrity areas: carbon accounting, additionality and permanence. It combines those factors with a Delivery Risk assessment that examines whether a project can produce the credits it forecasts.

Deep Sky One’s AAA-A rating reflects low overall integrity risk. Sylvera also found very low additionality risk because DAC projects remain heavily dependent on carbon credit revenue. The project performed strongly across carbon accounting and permanence criteria.

RELATED ARTICLE: Deep Sky Delivers North America’s First DAC Carbon Credits

Buyers demand clearer evidence of delivery

The assessment arrives as the durable carbon removal market enters a more disciplined phase.

Corporate buyers have become more selective about the projects they support. At the same time, demand has increasingly concentrated around larger and longer-term commitments. That places greater pressure on developers to demonstrate both environmental integrity and operational credibility.

For first-of-a-kind projects, those questions can materially affect financing.

“The DAC market is still nascent, and buyers need to know that projects can actually deliver with integrity. Pre-issuance Ratings provide buyers with a clear view of how a DAC developer is accounting for the risks involved in FOAK projects,” Hugo Lakin, CDR Lead, Sylvera

Independent assessments may therefore play a larger role in due diligence. Buyers need to evaluate not only how a project calculates carbon removal, but whether it can build, operate and deliver contracted volumes.

That matters particularly in DAC, where projects can require substantial upfront capital before meaningful revenue begins.

A potential benchmark for the DAC market

Sylvera designed the framework developed through the Deep Sky assessment to be replicable across the wider DAC sector.

That could give other developers a clearer route to demonstrating integrity before operations begin. It could also help investors compare projects using a more consistent set of criteria.

For corporate buyers, the value lies in risk management. Long-term carbon removal agreements can create financial, reputational and climate-accounting exposure if projects fail to deliver as expected.

For developers, credible third-party assessment could strengthen discussions with financiers and prospective buyers.

The broader significance reaches beyond Deep Sky One. As engineered carbon removal moves from demonstration projects toward commercial deployment, governance standards will increasingly shape which projects secure capital.

A more standardized approach to assessing integrity and delivery risk could help the DAC sector build that confidence before large volumes of credits reach the market.