Planeteers

What Planeteers does

Planeteers GmbH is a Hamburg-based climate technology company founded in December 2022 that develops marine carbon dioxide removal systems based on ocean alkalinity enhancement. The company's core technology combines two approaches: a closed patent-pending engineered weathering system that captures CO2 directly at industrial point sources and converts it into stable dissolved bicarbonate using limestone within minutes, and a patented Hydrated Carbonate Minerals (HCM) process that produces ikaite — a calcium carbonate hydrate released into marine environments to increase ocean alkalinity and absorb additional atmospheric CO2. All removals are continuously monitored through alkalinity, pH, and dissolved inorganic carbon measurements, with third-party verification conducted under Isometric's protocols for Enhanced Weathering in Closed Engineered Systems and Biogenic Carbon Capture and Storage.

The company serves three primary customer segments: municipalities and wastewater treatment plants (where CO2 and water co-locate), industrial emitters seeking point-source carbon capture, and corporate carbon buyers seeking verified removal credits. It generates revenue through two mechanisms: the sale of verified, ocean-storage CO2 removal credits (with pre-purchase agreements in place with Frontier, Milkywire, and Airminers), and managed-service modular system deployments at partner facilities under revenue-share-style arrangements. Planeteers runs direct enterprise sales with wastewater utilities and industrial sites across Germany, with planned expansion to Switzerland via Project NAUTILUS in 2026 in collaboration with Energie 360° AG.

Planeteers has progressed from a garage-built prototype in 2023 through four-site field testing in 2024 (Hamburg, Hetlingen, Kiel, Wuppertal) to its first production unit — Project HELIX at AZV Südholstein, Hetlingen — officially validated in December 2025. The company has raised a multi-million euro seed round from BonVenture, Energie 360° AG, and Carmeuse Ventures, and has set a capacity roadmap moving from a 1,000-ton unit in 2026 to 2,500-ton and 10,000-ton units in 2027–2028, with longer-term ambitions of megaton-scale by 2030 and gigatonne-per-year by 2050. Planeteers is led by founders Prof. Jens Hartmann (Chief Scientist), Dr. Frank Rattey, and Managing Director Florian Birner, and has received the Hamburg Founder Award 2024 and the German Sustainability Award 2025.

Name

Planeteers

Legal name

Planeteers GmbH

Website

https://planeteers.de

Company type

Private

Founded year

2022

Operating status

Operating

Headcount range

11–50 employees

Short description

Planeteers GmbH is a Hamburg-based climate technology company that removes CO2 via ocean alkalinity enhancement, using closed engineered weathering of limestone and patented HCM/ikaite chemistry, serving wastewater utilities, industrial emitters, and corporate carbon-credit buyers across Germany and Switzerland.

Ownership category

akta.pro rank

Product category

Marine Carbon Dioxide Removal

akta.pro primary industry

Ocean-Based Carbon Removal (Alkalinity Enhancement, Seaweed, Ocean Biomass Sinking) (EUABAFAF)

akta.pro secondary industries

Carbon Removal Project Development, Financing & Offtake (Developers, Aggregators, Buyers Clubs) (EUABAFAL), Carbon Removal Credits Trading (DAC, BECCS, Biochar, Mineralization) (EUAGAIAL)

Keywords

• Ocean alkalinity enhancement
• Carbon dioxide removal
• Engineered weathering systems
• Marine carbon capture
• Carbon removal credits

Headquarters

HQ city

Hamburg

HQ country

Germany

HQ region

Europe

Offices2 records

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Technology or R&D, Operations, Marketing or Sales, Infrastructure, Supply Chain

Revenue model

1. CO2 Removal Credits: Organizations purchase verified CO2 removal credits representing real, measurable storage of atmospheric or point-source CO2 in stable, ocean-verified form, validated by independent third-party experts including Isometric.
2. Modular System Deployment Partnerships: Planeteers provides technology, validation, and ongoing monitoring while partners provide site, infrastructure, and shared ambition. Organizations can partner to deploy modular systems at their own facilities for integrated carbon removal operations.

Pricing tiers

Go-to-market motion1 record

Distribution channels3 records

Marketing channels4 records

Core offering

Planeteers develops and deploys marine carbon dioxide removal technology using ocean alkalinity enhancement. Their patented Hydrated Carbonate Minerals (HCM) technology produces ikaite for atmospheric CO2 removal, while a patent-pending closed engineered weathering system captures CO2 from industrial point sources and converts it into stable dissolved bicarbonate using limestone and water. The company sells verified CO2 removal credits and deploys modular carbon removal systems at wastewater treatment plants and industrial facilities.

Product overview

Planeteers offers marine carbon dioxide removal technology based on ocean alkalinity enhancement through two complementary core products: CO₂ from Point Sources (closed engineered weathering system capturing CO₂ at industrial sources and converting it to bicarbonate using limestone) and Atmospheric CO₂ Removal using patented HCM (Hydrated Carbonate Minerals) technology that produces ikaite for ocean alkalinity enhancement. The portfolio includes production units (Project HELIX), commercial plants (Projects OSTREA and NAUTILUS), and a pilot field testing program across four German sites. The company sells verified CO₂ removal credits to organizations seeking measurable climate impact.

Differentiator

Problem solved

Functional benefit

Products and services

• CO2 from Point Sources Closed patent-pending engineered weathering system that captures CO2 directly at industrial point sources before it reaches the atmosphere. Captured CO2 is dissolved in water and converted into stable dissolved bicarbonate using alkaline materials such as limestone within minutes, enabling verifiable permanent storage within the oceanic carbon cycle. Designed for scalable integration with existing industrial and municipal infrastructure.
• Atmospheric CO2 Removal (HCM Technology) Patented Hydrated Carbonate Minerals (HCM) technology that produces ikaite—a naturally occurring calcium carbonate hydrate. When released into marine environments, ikaite gradually dissolves to increase ocean alkalinity and enhance CO2 uptake from the atmosphere, storing it as bicarbonate. This controlled pathway enables large-scale, permanent, and verifiable carbon storage in the ocean.
• CO2 Removal Credits Verified, permanent CO2 removal credits representing real measurable storage of atmospheric or point-source CO2 in stable ocean-verified form, validated by independent third-party experts under Isometric standards. Organizations purchase these credits to meet climate commitments with high-integrity, permanent removals.
• Project HELIX Planeteers' first production unit at AZV Südholstein wastewater treatment plant in Hetlingen, Germany. Validates the closed engineered weathering system under operational conditions, converting biogenic CO2 captured at point sources into dissolved bicarbonate through accelerated weathering of limestone.
• Project OSTREA Commercial-scale facility at a North Germany/Baltic Sea wastewater treatment plant. Applies the closed engineered weathering approach at expanded operational capacity to validate long-term performance and operational scalability, targeting a 1,000-ton unit in 2026.
• Project NAUTILUS Commercial deployment at wastewater treatment plant in Switzerland, advancing technology deployment within the Swiss regulatory framework. Developed in collaboration with partner and investor Energie 360°, marking the company's expansion beyond Germany.
• Field Testing Program Extensive pilot phase across four different facilities in Germany (Hamburg, Hetlingen, Kiel, and Wuppertal) to validate technology under real operating conditions with real CO2 streams and water systems.

Quantifiable outcome

• First certified ton of CO2 removed under Isometric standards
• +3 more outcomes

Named customers3 records

Segments4 records

Ideal customer profiles4 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature3 records

Partnerships

Four partnerships are on record, tiered core and minor.

• AZV SüdholsteincoreStrategic or Co-development Partner · 1 December 2025Wastewater treatment plant in Hetlingen, Germany hosting Project HELIX - Planeteers' first production unit validating closed engineered weathering under operational conditions since December 2025.
• CarmeuseminorStrategic or Co-development Partner · 1 January 2025Belgium-based global limestone and lime products company, investing through Carmeuse Ventures. Their core products are being used as potential carbon sinks alongside direct emissions reduction efforts.
• IsometriccoreTechnology or IntegrationThird-party verification organization providing standardized verification of reaction efficiency, permanence, and ocean safety under Enhanced Weathering in Closed Engineered Systems protocol.
• Normec VerifaviacoreTechnology or IntegrationIndependent validation organization that officially validated Project HELIX in Hetlingen in December 2025, with results listed by Isometric.

Scale indicators6 records

Recent moves6 records

Expansion highlights6 records

Direct peers

• Ebb Carbon: San Francisco-based ocean alkalinity enhancement company using electrochemical processes to remove CO2 from the atmosphere and store it in the ocean. Closest direct competitor to Planeteers in the OAE pathway with a similar credit-sale business model.
• 44.01: Oman-headquartered carbon removal company that mineralizes CO2 into stable carbonate rocks via ocean-based enhanced weathering. Operates in the same ocean alkalinity/carbon mineralization space as Planeteers and sells verified removal credits.
• Captura: Pasadena-based startup developing electrochemical ocean CO2 removal technology that pulls dissolved CO2 from seawater. Competes with Planeteers in the marine carbon removal category with a different but related capture mechanism.

Broad incumbents

• Climeworks: Swiss- Icelandic industry leader in direct air capture (DAC) operating the world's largest DAC plant (Mammoth). Competes with Planeteers for corporate removal credit budgets but uses solid sorbent DAC rather than ocean alkalinity enhancement.
• Heirloom Carbon: California-based DAC company using limestone-based enhanced weathering with a technology approach (limestone + CO2 → carbonate) that is chemically analogous to Planeteers' point-source engineered weathering process.
• CarbonCapture Inc. US-based DAC company commercializing solid sorbent direct air capture systems. Competes with Planeteers in the voluntary carbon removal credit market for the same pool of corporate buyers.

Emerging players

• CarbonCure Technologies: Canadian company that mineralizes CO2 into concrete during the concrete mixing process. Adjacent to Planeteers' mineralization approach but anchored in the building materials vertical rather than ocean storage.
• Carbonfuture: Germany-based digital marketplace and MRV infrastructure provider for high-quality carbon removal credits. Comparable to Planeteers as an emerging European removal ecosystem player, though Carbonfuture is a platform rather than a project developer.
• CarbonOrO: German point-source CO2 capture startup using amine-based post-combustion capture. Overlaps with Planeteers' point-source carbon capture offering but uses a different capture chemistry and primarily targets industrial flue gas.

Others

• C-Quest Capital: Global carbon project developer and credit originator focused on nature-based and technological removal solutions. Operates as an aggregator/buyer in the same voluntary carbon market where Planeteers sells its credits, making it an adjacent ecosystem participant.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks6 records

Key highlights7 records

Customer concentration

• LinkedInlinkedin.com/company/planeteersgmbh

Compliance4 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles3 records

Funding overview

Funding rounds1 record

Investors3 records

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Planeteers