Stiesdal

What Stiesdal does

Stiesdal is a Danish climate technology company founded in 2016 by Henrik Stiesdal, a wind power pioneer who built his first test turbine in 1976 and sold the commercial license to Vestas in 1979. The company develops and commercializes three industrial hardware platforms targeting complementary climate mitigation pathways: (1) Tetra floating offshore wind foundations via subsidiary Stiesdal Offshore, demonstrated at the TetraSpar Demonstrator in Norway at 200m water depth (December 2021); (2) HydroGen alkaline electrolysers via subsidiary Stiesdal Hydrogen, with a 3.1-MW platform and a new 6.5-MW unit achieving system CAPEX below EUR 500/kW—approximately half the cited European market average of EUR 1,000/kW; and (3) SkyClean pyrolysis plants via subsidiary Stiesdal SkyClean, which convert agricultural and forestry waste into biochar for permanent carbon storage and bioenergy, scaled from a 200-kW test plant in 2021 to a 20-MW commercial plant in Vraa, Denmark (October 2024)—the world's largest pyrolysis plant for CO2 capture and green energy.

The company is headquartered across multiple Danish locations (Copenhagen, Give, Aarhus, Vraa, and others) with approximately 140 employees representing 20 nationalities as of 2024, and operates four wholly-owned subsidiaries (Stiesdal Offshore, Stiesdal Hydrogen, Stiesdal SkyClean, and Stiesdal Storage) plus a 35% stake in Agri Energy, a biogenic energy parks joint venture. Revenue mechanics span hardware sales of electrolyser units and pyrolysis plants, technology licensing (e.g., HydroGen technology licensed to Reliance Industries for manufacturing in India), and biochar carbon credit transactions certified under the European Biochar Certificate. The go-to-market is enterprise field sales targeting large industrial partners across three verticals: renewable energy producers, agriculture and forestry, and offshore wind developers.

Strategic differentiation rests on industrialization as the core cost-reduction lever, supported by the founder's 1,000+ patent portfolio and a leadership team that includes individuals involved in the design of more than 50% of all offshore wind turbines globally. Major commercial partners include Reliance Industries (India electrolyser manufacturing, signed October 2021), CIP (floating offshore wind, October 2024), Maersk Supply Service, PensionDanmark (equity investor), and European Energy (Aabenraa green hydrogen facility). The company received a DKK 124 million grant from the Danish Pyrolysepuljen fund in June 2022 to scale the SkyClean platform.

Name

Stiesdal

Legal name

Stiesdal A/S

Website

https://stiesdal.com

Company type

Private

Founded year

2016

Operating status

Operating

Headcount range

51–100 employees

Short description

Stiesdal is a Danish climate technology company founded in 2016 that develops and commercializes three industrial hardware platforms—floating offshore wind foundations, low-cost green hydrogen electrolysers, and pyrolysis-based carbon capture systems—to serve energy producers, agricultural operators, and offshore wind developers.

Ownership category

akta.pro rank

Product category

Climate Technology / Renewable Energy Equipment

akta.pro primary industry

Offshore Wind Substructures & Marine Engineering (Monopiles, Jackets, Floating) (EUAMACAE)

akta.pro secondary industries

Advanced Wind Technology R&D (Floating Offshore, Airborne Wind, New Rotor/Blade Concepts) (EUAMAOAB), Hydrogen Production Supply & Offtake (Green/Blue H2) for Utility Blending (EUAJAJAF), E‑Fuels & Synthetic Hydrocarbons (e‑kerosene, e‑diesel, e‑gasoline, e‑methane) (EUABAIAA)

Keywords

• Floating offshore wind foundations
• Green hydrogen electrolysers
• Pyrolysis carbon capture
• Biochar bioenergy systems
• Climate technology hardware

Headquarters

HQ city

Give

HQ country

Denmark

HQ region

Europe

Offices8 records

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

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

Revenue model

1. Electrolysis Systems (HydroGen): Sale of HydroGen electrolyser units for green hydrogen production. New 6.5-MW unit with system CAPEX below EUR 500/kW, positioned at half the European market average.
2. SkyClean Pyrolysis Plants: Sale of turnkey pyrolysis plants for carbon capture and green fuel production. Each plant can reduce CO2 emissions by 42,000 tons annually.
3. Floating Offshore Wind Foundations (Tetra): Industrialized floating foundations for offshore wind deployment in deep-water environments.
4. Carbon Credits / Biochar Certificates: Revenue from carbon sequestration via biochar production. Biochar certified under European Biochar Certificate standard. SkyClean biochar can qualify as 'permanent carbon storage' under EU CRCF directive.
5. Technology Licensing: Licensing of HydroGen Electrolyzer technology for manufacturing in India via partnership with Reliance Industries.

Pricing tiers

Go-to-market motion1 record

Distribution channels3 records

Marketing channels4 records

Core offering

Stiesdal develops and commercializes three proprietary climate technology platforms: (1) Tetra industrialized floating offshore wind foundations for deep-water wind energy; (2) HydroGen alkaline electrolysers (3.1-MW and 6.5-MW units) for low-cost green hydrogen production for Power-to-X; and (3) SkyClean pyrolysis plants that convert agricultural and forestry organic by-products into biochar for permanent carbon storage and bioenergy for green fuels. Each platform is delivered as turnkey hardware with associated engineering, certifications, and licensing models.

Product overview

Stiesdal is a climate technology company operating as a group of four subsidiaries: Stiesdal A/S (parent), Stiesdal Offshore, Stiesdal Hydrogen, and Stiesdal SkyClean. The portfolio consists of three distinct product lines: (1) Stiesdal Offshore offers the Tetra/TetraSpar industrialized floating offshore wind foundation for deep-water wind energy; (2) Stiesdal Hydrogen provides HydroGen alkaline electrolyzer units (3.1-MW and 6.5-MW models) for green hydrogen and Power-to-X production; and (3) Stiesdal SkyClean delivers SkyClean pyrolysis plants for biochar carbon capture combined with green fuel production. The company also holds 35% ownership in Agri Energy, which builds biogenic energy parks. The product architecture follows an industrialization approach with standardized, scalable modules for mass production.

Differentiator

Problem solved

Functional benefit

Brands

• Tetra: Industrialized floating offshore wind foundation developed by Stiesdal Offshore for low-cost offshore wind energy in deep-water locations.
• HydroGen
• SkyClean

Products and services

• HydroGen 6.5-MW Electrolyser Alkaline electrolyser unit developed by Stiesdal Hydrogen for green hydrogen production targeted at Power-to-X applications across industrial, transport, and energy sectors. Designed for industrial-scale renewable electricity integration with low CAPEX and O&M cost.
• HydroGen 3.1-MW Electrolyser First-generation alkaline electrolyser platform for green hydrogen production for industrial and Power-to-X use cases. Per-MW O&M cost is 50% lower than prior benchmarks.
• Tetra Floating Offshore Wind Foundation Industrialized floating offshore wind foundation developed by Stiesdal Offshore for deep-water wind energy deployment. Designed for mass-manufacture in high-cost countries and for installation in locations where fixed-bottom foundations are not feasible, enabling access to unlimited low-cost offshore wind.
• SkyClean Pyrolysis Plant Turnkey pyrolysis plant developed by Stiesdal SkyClean that converts organic by-products from agriculture, forestry, and industry into biochar for permanent carbon storage and bioenergy (bio-oil and gas) for green fuel production. Each 20 MW plant can reduce CO2 emissions by 42,000 tons annually; biochar is certified under the European Biochar Certificate and can qualify as permanent carbon storage under the EU CRCF directive.

Quantifiable outcome

• 42,000 tons CO2 reduction per SkyClean plant annually
• +7 more outcomes

Named customers1 record

Segments3 records

Ideal customer profiles3 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature3 records

Partnerships

Seven partnerships are on record, tiered core and flagship.

• CIP (Copenhagen Infrastructure Partners)coreStrategic or Co-development Partner · 23 October 2024CIP and Stiesdal Offshore partnership for floating offshore wind. CIP is a major independent fund manager managing over EUR 20 billion in assets focused on greenfield energy infrastructure projects globally.
• Sauter DanmarkcoreStrategic or Co-development Partner · 24 January 2024Stiesdal SkyClean and Sauter Danmark established joint venture to establish a new cooperative in Danish agriculture focused on energy production. Created company: Agri Energy (Stiesdal owns 35%).
• Maersk Supply ServicecoreStrategic or Co-development Partner · 8 September 2022Maersk Supply Service and Stiesdal Offshore entered floating wind partnership. Maersk brings offshore marine expertise and capabilities.
• Reliance Industries / Reliance New Energy Solar LimitedcoreStrategic or Co-development Partner · 12 October 2021Cooperation agreement to collaborate on technology development and manufacturing of Stiesdal's HydroGen Electrolyzer in India. Stiesdal provides electrolyser technology and Reliance provides manufacturing capacity at Dhirubhai Ambani Green Energy Giga Complex in Jamnagar (5,000+ acres). Project targets 3 GW electrolyser plant as part of India's National Green Hydrogen Mission.
• AndelcoreStrategic or Co-development Partner · 20 April 2021Andel and Stiesdal joined forces on large-scale energy storage in hot rocks. Andel is a Danish energy company.
• TEPCO Renewable PowerflagshipStrategic or Co-development Partner · 4 February 2021TEPCO Renewable Power joined the TetraSpar demonstration project to test industrialized floating offshore wind foundation. TetraSpar Demonstrator commissioned and in operation December 2021.
• Shell and innogy (now E.ON)flagshipStrategic or Co-development Partner · 13 February 2019Shell and innogy partnered with Stiesdal Offshore Technologies to build floating wind demonstration project. Early strategic collaboration that helped establish TetraSpar concept.

Scale indicators8 records

Recent moves9 records

Expansion highlights6 records

Direct peers

• Nel ASA: Norwegian-headquartered alkaline and PEM electrolyser manufacturer with a similar focus on industrial-scale green-hydrogen production. Most direct publicly listed peer to Stiesdal Hydrogen, targeting cost reduction and large project offtakes in Europe and the US.
• ITM Power: UK-based PEM electrolyser manufacturer focused on large-scale green-hydrogen plants for industrial and power-to-x applications. Direct peer to Stiesdal Hydrogen, with comparable end markets and product category.
• Thyssenkrupp Nucera: German alkaline-water-electrolysis specialist serving large utility and industrial hydrogen projects globally. Closest scaled alkaline-electrolyser peer to Stiesdal's HydroGen platform and a key reference point for cost-down trajectories.
• Principle Power: US-based developer of the WindFloat floating offshore wind foundation, a leading direct competitor to Stiesdal's Tetra platform in the deep-water floating-wind space, serving similar utility and developer customers.
• BW Ideol: French floating offshore wind foundation developer using a concrete-barge design, directly competing with Stiesdal's Tetra concept for commercial-scale deep-water wind projects in Europe and Asia-Pacific.
• Plug Power: US-based hydrogen equipment and fuel-cell company with a growing electrolyser portfolio and a similar B2B enterprise sales motion. Direct peer to Stiesdal Hydrogen, particularly in industrial-decarbonization use cases.
• Doosan Enerbility: South Korean heavy-industry company with a dedicated alkaline electrolyser business and large-scale hydrogen ambitions in Asia. Comparable to Stiesdal Hydrogen in alkaline-electrolyser technology and pursuit of large project pipelines.

Broad incumbents

• Siemens Energy: Global energy technology incumbent offering both wind turbines (Siemens Gamesa) and the Silyzer hydrogen electrolyser, making it the most diversified peer across Stiesdal's three business lines. Henrik Stiesdal was previously CTO of Siemens Wind Power.
• Equinor (Hywind): Norwegian integrated energy major and operator of the Hywind floating wind farm, the world's first operational floating offshore wind project. Acts as a broad incumbent and potential customer/competitor for Stiesdal Offshore's Tetra foundation.

Emerging players

• Carbofex: Finnish pyrolysis technology provider focused on biochar production and carbon removal, the closest pure-play peer to Stiesdal SkyClean. Comparable in target market (voluntary carbon, agricultural waste) and in scale of current deployments.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks6 records

Key highlights7 records

Customer concentration

Compliance2 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles9 records

Subsidiaries5 records

Funding overview

Funding rounds2 records

Investors2 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 Stiesdal