CELLSIUS - Project e-Sling and Project H2
Cellsius is a non-profit ETH Zürich student association developing zero-emission aircraft propulsion systems across three demonstrator airframes: e-Sling (battery-electric), H2-Sling (hydrogen fuel cell), and Project Liquid H2 (cryogenic liquid hydrogen). Funded via corporate sponsors, individual patrons, and institutional partners.
- Company typePrivate
- Founded2020
- HeadquartersDübendorf, Switzerland
- Headcount—
- GTM typeB2B
- OfferingHardware or Manufacturing
What CELLSIUS - Project e-Sling and Project H2 does
Verein Cellsius is a non-profit association (Verein) founded in 2020 by ETH Zürich students to develop sustainable aircraft propulsion systems. Headquartered at Wangenstrasse 72, CH-8600 Dübendorf, Switzerland, the organization operates from the ETH Zürich Innovation Park and Dübendorf airfield, drawing on rotating annual cohorts of 10-12 mechanical and electrical engineering focus students plus an extended network of 40+ alumni, freelancers, and board members. The mission targets the aviation sector's contribution to climate change, which the organization cites as 2-3% of global CO2 emissions with total climate impact approximately 3x higher when including non-CO2 effects.
The product portfolio consists of three demonstrator airframes rather than commercial offerings: the e-Sling (a battery-electric four-seater conversion of a Sling TSi kit that completed its maiden flight in September 2022 as the world's first certified four-seater electric aircraft, with 180km range and 1h15 cruise flight), the H2-Sling (a 100kW hydrogen fuel cell conversion of a Sling High Wing delivering 200km range and 2h cruise flight, with gaseous hydrogen storage and assembly completed and EAS-inspected in October 2025), and Project Liquid H2 (a cryogenic liquid hydrogen variant targeting 500km range with two 5kg tanks at -253°C and 4h flight time). Critical sub-systems are developed in-house, including an Electronic Control Unit built in MATLAB Simulink with automated C-code generation, custom Power Distribution Units (H2-PDU and HV-PDU), printed circuit boards processing 30+ sensor inputs, a 100kW+ electric motor with >90% efficiency, a custom inverter, an LH2 cryogenic storage system with vacuum-insulated double-wall tanks, a heat exchanger bridging -250°C to 70°C, and additively manufactured components designed via generative algorithms. Key technology partners include Pilatus (motor mount fabrication, exterior painting), Sling Aircraft (airframe platform, extended wing), and PowerCell (fuel cell stack supply).
Cellsius operates a sponsorship-funded model with no commercial product sales. Revenue flows from corporate sponsorships structured in tiers (Platinum, Gold, Silver, Lithium) with 200+ supporting organizations, individual patron donation packages ranging from CHF 50 (Junior Flight Officer) to CHF 1,000 (Senior Captain), and in-kind contributions from academic and industrial partners. The customer base spans academic research (primary), aviation enthusiasts and individual patrons, and corporate sponsors across aviation, energy, technology, and manufacturing sectors. The organization is not venture-backed, has no equity investors, and is governed by a board of directors with ETH Zürich students rotating through focus project cohorts annually.
CELLSIUS - Project e-Sling and Project H2 firmographics
Firmographics- Name
- CELLSIUS - Project e-Sling and Project H2
- Legal name
- Verein Cellsius
- Website
- https://cellsius.aero
- Company type
- Private
- Founded year
- 2020
- Operating status
- Operating
- Short description
- Cellsius is a non-profit ETH Zürich student association developing zero-emission aircraft propulsion systems across three demonstrator airframes: e-Sling (battery-electric), H2-Sling (hydrogen fuel cell), and Project Liquid H2 (cryogenic liquid hydrogen). Funded via corporate sponsors, individual patrons, and institutional partners.
- Ownership category
- akta.pro rank
CELLSIUS - Project e-Sling and Project H2 industry classification
Industry- Product category
- Sustainable Aviation Propulsion
- NAICS
- Battery Manufacturing (33591), Bare Printed Circuit Board Manufacturing (334412), Switchgear and Switchboard Apparatus Manufacturing (335313)
- SIC
- Aircraft & Parts (3720), Aircraft Engines & Engine Parts (3724), Electronic & Other Electrical Equipment (No Computer Equip) (3600)
- akta.pro primary industry
- Training & Light Sport Fixed-Wing Aircraft Manufacturing (IMABAAAE)
- akta.pro secondary industries
- Battery Management Systems (BMS) & Battery Electronics (IMAGAHAC), Battery Management Systems (BMS) & Pack Electronics Manufacturing (EUAFABAJ), Battery Pack Manufacturing & Module Assembly (EUAFABAI), Battery Management System (BMS) & HV Control Electronics Manufacturing (IMACACAH)
Keywords
Where CELLSIUS - Project e-Sling and Project H2 is headquartered
LocationHeadquarters
- HQ city
- Dübendorf
- HQ country
- Switzerland
- HQ region
- Europe
Offices1 record
Markets served
CELLSIUS - Project e-Sling and Project H2 business model
Business model- GTM type
- B2B
- Offering type
- Hardware or Manufacturing
- Cost components
- Personnel, Technology or R&D, Operations, Infrastructure, Supply Chain
Revenue model
- Corporate Sponsorships: Corporate sponsors provide financial and material support at various tiers (Platinum, Gold, Silver, Lithium). Sponsors receive recognition on aircraft, website, and at events.
- Patron/Donation Programs: Individual patrons make one-time contributions (CHF 50-1000) through tiered packages (Junior Flight Officer, Second Officer, First Officer, Captain, Senior Captain) receiving name recognition, merchandise, and event invitations.
Pricing tiers
| Model | Billing | Price |
|---|---|---|
| Subscription | Annual | Junior Flight Officer - CHF 50 |
| Subscription | Annual | Second Officer - CHF 100 |
| Subscription | Annual | First Officer - CHF 250 |
| Subscription | Annual | Captain - CHF 500 |
| Subscription | Annual | Senior Captain - CHF 1000 |
Go-to-market motion1 record
Distribution channels1 record
Marketing channels7 records
CELLSIUS - Project e-Sling and Project H2 product offering
Product offeringCore offering
CELLSIUS is a non-profit student association that develops and flight-tests zero-emission aircraft propulsion systems through three projects: the e-Sling (battery-electric four-seater), the H2-Sling (hydrogen fuel cell, 100kW, gaseous H2), and Project Liquid H2 (cryogenic LH2 storage at -253°C). The organization designs propulsion systems, control electronics, power distribution, and aircraft integration components in-house, supported by corporate sponsors and individual patrons.
Product overview
CELLSIUS develops sustainable aircraft propulsion systems through three main projects: the e-Sling (battery-electric four-seater, maiden flight 2022), the H2-Sling (hydrogen fuel cell aircraft with 100kW system achieving 200 km range), and Project Liquid H2 (advanced liquid hydrogen system targeting 500 km range). The company also develops core subsystems including Electronic Control Units, Power Distribution Units, custom PCBs, electric motors with inverters, cryogenic LH2 tanks, heat exchangers, and extended wing structures. All components are developed in-house with significant support from ETH Zurich and industrial partners like Pilatus and Sling Aircraft.
Differentiator
Problem solved
Functional benefit
Brands
- H2-Sling: Hydrogen fuel cell powered aircraft based on Sling High Wing kit, featuring 100kW fuel cell system with gaseous hydrogen storage for 200km range
- e-Sling
- Project Liquid H2
Products and services
- e-Sling Battery-electric four-seater aircraft based on the Sling TSi kit, equipped with a modular battery system and self-developed propulsion system. Achieves 180 km range with 1 hour 15 minute flight time and 0g CO2 emissions. Currently in flight testing phase.
- H2-Sling Hydrogen fuel cell powered aircraft with 100kW fuel cell system using gaseous hydrogen. Electrochemical conversion produces only water as byproduct. Achieves 200 km range with 2 hours of cruise flight and 0g CO2 emissions. Undergoing certification for first flight.
- Project Liquid H2 Advanced hydrogen propulsion system based on the H2-Sling platform using liquid hydrogen stored at -253°C in vacuum-insulated tanks with a custom heat exchanger feeding the fuel cell. Targets 500 km range with 4 hours of flight time and 0g CO2 emissions.
Quantifiable outcome
- First hydrogen-powered aircraft developed by students, setting precedent for academic hydrogen aviation research
- +2 more outcomes
Companies that use CELLSIUS - Project e-Sling and Project H2
Customer profileNamed customers1 record
Segments3 records
Ideal customer profiles3 records
CELLSIUS - Project e-Sling and Project H2 technology and API
TechnologyTechnology focussed Yes
API detail
- Has API
- No
- API docs
- API detail
Core technology
AI maturity
App detail
AI capability3 records
Feature10 records
CELLSIUS - Project e-Sling and Project H2 partnerships and signals
Strategic signalPartnerships
Eight partnerships are on record, tiered core and minor.
- Sling AircraftcoreSouth African aircraft kit manufacturer whose Sling High Wing platform serves as the base aircraft for both e-Sling and H2-Sling projects. CELLSIUS visited Johannesburg to coordinate wing extension manufacturing. Long-standing collaboration since e-Sling development.
- PilatuscoreSwiss aircraft manufacturer producing the motor mount structure for H2-Sling. Painted the aircraft exterior and provided manufacturing expertise. Dr. Urs Thomann serves as patron, contributing industry leadership perspective.
- PowerCellcoreSwedish fuel cell manufacturer supplying the hydrogen fuel cell stack. Stack delivers over 100kW power at only 40kg weight. CELLSIUS team visited PowerCell in Gothenburg to understand serial production systems.
- Experimental Aviation of Switzerland (EAS)coreSwiss experimental aviation authority conducting aircraft inspections and certification. Inspected and accepted the H2-Sling in October 2025 as part of the certification process.
- ETH ZürichcoreHome institution providing student talent, academic supervision through IDSC (Institute for Dynamic Systems and Control), and facilities at Innovation Park Dübendorf. Multiple focus project cohorts since 2020.
- LAT and SWISSminorAviation industry partners enabling team travel to South Africa to coordinate with Sling Aircraft manufacturer.
- Bundesamt für Zivilluftfahrt (BAZL)coreSwiss Federal Office of Civil Aviation overseeing experimental aircraft certification requirements and safety standards for hydrogen aircraft operations.
- IDSC (Institute for Dynamic Systems and Control)coreETH Zürich institute supervising ECU development through two bachelor's theses, providing academic guidance for control system engineering.
Scale indicators9 records
Recent moves6 records
Expansion highlights6 records
CELLSIUS - Project e-Sling and Project H2 competitors and assessment
Company assessmentMarket position
Weaknesses1 record
Competitive moat5 records
Key risks6 records
Key highlights7 records
Customer concentration
CELLSIUS - Project e-Sling and Project H2 social profiles
Digital presenceCELLSIUS - Project e-Sling and Project H2 financial estimates
Financial estimateRevenue estimate
Valuation estimate
CELLSIUS - Project e-Sling and Project H2 leadership team
Management profileNumber of profiles
Profiles3 records
CELLSIUS - Project e-Sling and Project H2 funding detail
Funding detailFunding overview
Funding rounds
Investors
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
CELLSIUS - Project e-Sling and Project H2 M&A and investment
M&A and investmentM&A
Investments
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about CELLSIUS - Project e-Sling and Project H2
What does CELLSIUS - Project e-Sling and Project H2 do?
CELLSIUS is a non-profit student association that develops and flight-tests zero-emission aircraft propulsion systems through three projects: the e-Sling (battery-electric four-seater), the H2-Sling (hydrogen fuel cell, 100kW, gaseous H2), and Project Liquid H2 (cryogenic LH2 storage at -253°C). The organization designs propulsion systems, control electronics, power distribution, and aircraft integration components in-house, supported by corporate sponsors and individual patrons.
Is CELLSIUS - Project e-Sling and Project H2 a public or private company?
CELLSIUS - Project e-Sling and Project H2 is a private company. It is classified as nonprofit foundation owned and is currently operating.
When was CELLSIUS - Project e-Sling and Project H2 founded?
CELLSIUS - Project e-Sling and Project H2 was founded in 2020.
Where is CELLSIUS - Project e-Sling and Project H2 based?
CELLSIUS - Project e-Sling and Project H2 is headquartered in Dübendorf, Switzerland, in the Europe region.
How does CELLSIUS - Project e-Sling and Project H2 make money?
Two revenue lines are on record. Corporate Sponsorships are the primary driver. The others are patron/Donation Programs.
Does CELLSIUS - Project e-Sling and Project H2 have an API?
No public API is recorded for CELLSIUS - Project e-Sling and Project H2.
What industry is CELLSIUS - Project e-Sling and Project H2 in?
CELLSIUS - Project e-Sling and Project H2's product category is Sustainable Aviation Propulsion. Its primary akta.pro industry code is IMABAAAE, Training & Light Sport Fixed-Wing Aircraft Manufacturing, with a secondary code of IMAGAHAC, Battery Management Systems (BMS) & Battery Electronics. Its NAICS code is 33591 and its SIC code is 3720.