What Eternal Sun does

Eternal Sun (legal entity: Eternalsun Spire) is a Dutch solar module testing equipment manufacturer and inspection services provider founded in 2011 and headquartered in The Hague, Netherlands. The company designs and sells high-end solar simulators used to measure the current-voltage (IV) characteristics of photovoltaic modules. Its product portfolio spans LED-based steady-state solar simulators and XENON-based flash solar simulators, all achieving A+A+A+ class illumination per IEC 60904-9 ed. 3. Flagship products include the SPIRE Xenon Solar Flasher, SPIRE Temperature Controlled Laboratory Flasher, Mini LED Light Soaker, High Performance Light Soaker (HPLS AAA), and Large Area Steady State (LASS AAA), with test setups tailored to PERC, IBC, HJT, perovskite, and CdTe cell technologies as well as bifacial, half-cut, shingled, and large-format modules.

Eternal Sun monetizes through direct sales of capital equipment to solar module manufacturers, PV research institutions, and certification bodies, complemented by professional services including PV import testing at the Ports of Rotterdam and Valencia and factory inspections in China and South-East Asia. In June 2025, the company acquired key assets of German cell-level simulator developer WAVELABS, forming a wholly-owned subsidiary (WAVELABS Eternal Sun) in Leipzig that extends coverage down to cell-scale testing and adds LED projection-based simulators to the lineup. The go-to-market is enterprise field sales, supported by technical content marketing including webinars, whitepapers, and IEC-standards-based application guidance.

The company is privately held, employs between 11 and 50 people, and operates from the Netherlands with a German subsidiary and service points across major European ports and Asian manufacturing hubs. Leadership comprises founder and CTO Stefan Roest, CEO Florian van Rijn van Alkemade, and CCO Erik Bentschap Knook. Recent ownership changes include a 2025 investment by Dutch firm Bolster, which acquired stakes previously held by Vermec and the ABN AMRO Sustainable Impact Fund.

Name

Eternal Sun

Legal name

Eternalsun Spire

Website

https://eternalsunspire.com

Company type

Private

Founded year

2011

Operating status

Operating

Headcount range

11–50 employees

Short description

Eternal Sun is a Dutch manufacturer of high-end LED and XENON solar simulators for photovoltaic module IV-testing, plus PV import testing services at European ports and factory inspections in Asia. It serves solar module makers, research labs, and certification bodies worldwide.

Ownership category

akta.pro rank

Product category

Solar Testing Equipment

NAICS

Instrument Manufacturing for Measuring and Testing Electricity and Electrical Signals (334515), Testing Laboratories and Services (54138), Commercial, Industrial, and Institutional Electric Lighting Fixture Manufacturing (335132)

SIC

Measuring & Controlling Devices, Nec (3829), Industrial Instruments For Measurement, Display, And Control (3823), Optical Instruments & Lenses (3827)

akta.pro primary industry

Solar Quality, Testing, Certification & Standards (Lab Testing, Inspections, Compliance) (EUAMABAN)

Keywords

• Solar testing equipment
• LED solar simulators
• Flash sun simulators
• PV inspection services
• Solar module testing

Headquarters

HQ city

The Hague

HQ country

Netherlands

HQ region

Europe

Offices1 record

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

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

Revenue model

1. Solar Simulator Hardware Sales: Sale of high-end LED-based steady-state solar simulators and XENON-based flash sun simulators for solar panel testing. Products include various models for manufacturing and laboratory purposes with different specifications for temperature control, spectrum range, and testing capabilities.
2. PV Testing & Inspection Services: Testing and inspection services including PV import testing at ports of Rotterdam and Valencia, factory inspections in China and South-East Asia, and setup of certification labs according to IEC standards.
3. Cell Testing Platform: Dedicated cell testing platform for precise, reliable results at every scale through Wavelabs technology.

Go-to-market motion1 record

Distribution channels4 records

Marketing channels5 records

Core offering

Eternal Sun manufactures and sells high-end LED-based steady-state solar simulators and XENON-based flash sun simulators used for solar panel IV-testing in laboratories and manufacturing environments, achieving A+A+A+ class illumination per IEC 60904-9 ed. 3. The company also provides PV import testing services at the ports of Rotterdam and Valencia, factory inspections in China and South-East Asia, and helps customers set up certification labs according to IEC 61215, IEC 61730 and IEC 61853 standards.

Product overview

Eternal Sun (branded as Eternalsun Spire) is a provider of solar module testing solutions consisting of both hardware products and inspection services. The product portfolio centers on LED-based steady-state solar simulators and XENON-based flash sun simulators for IV-testing of solar panels, organized under two main categories: manufacturing solar simulators and laboratory solar simulators. Key products include the Class AAA Steady-state LED Solar Simulator, SPIRE Xenon Solar Flasher, SPIRE Temperature Controlled Laboratory Flasher, and Mini LED Light Soaker. The company expanded its offerings in 2025 through the acquisition of German company WAVELABS, forming the subsidiary WAVELABS Eternal Sun based in Leipzig, which adds LED projection-based solar simulators to the lineup. Complementing the hardware products are testing and inspection services including PV import testing at the ports of Rotterdam and Valencia, and factory inspections in China and South-East Asia. The test setups address specific technologies including PERC, IBC, HJT, Perovskite, CdTe, and are capable of handling bifacial, half-cut cell, shingled, and large modules.

Differentiator

Problem solved

Functional benefit

Brands

• SPIRE: Product line of solar simulators including SPIRE Xenon Solar Flasher and SPIRE Temperature Controlled Laboratory Flasher for solar panel IV testing

Products and services

• Steady-state LED Solar Simulator (Class AAA) A+A+A+ LED-based steady-state solar simulator for laboratory purposes, supporting all PV technologies including Tandem/Perovskite. Features wide and tunable spectrum for tandem matching, adjustable irradiance, and temperature control from 15°C to 85°C. Used by solar module manufacturers and high-end PV research groups.
• SPIRE Xenon Solar Flasher Flash sun simulator for solar panel IV-testing suitable for both laboratory and manufacturing purposes. Provides A+A+A+ class illumination per IEC 60904-9 ed. 3, Xenon Single Long Pulse >110ms, wide spectrum 300-1200nm, and market-leading repeatability and reproducibility. Used by module manufacturers for inline quality control and maximum power determination.
• SPIRE Temperature Controlled Laboratory Flasher Laboratory flash sun simulator for high-accuracy temperature coefficient measurements (IEC 61215) and Energy Rating determination (IEC 61853). Features A+A+A+ class illumination per IEC 60904-9 ed. 3, Xenon Single Long Pulse 230ms, wide spectrum 300-1200nm, and stable uniform temperature control from 10°C to 85°C.
• Mini LED Light Soaker Steady-state solar simulator for cells up to mini modules with a 50x50cm testing area. Available in wide or extra-wide active spectrum range, with Steady State Class A+A+A+ performance up to 36,000 hours without interruption, precise sample temperature control (15-85°C), and full range IV measurement from 60mA to 20A with reliable MPP Tracking.
• High Performance Light Soaker (HPLS AAA) High performance LED-based light soaker for solar module testing with Class AAA performance standards, used by solar manufacturers and research organizations.
• Large Area Steady State (LASS AAA) Large area LED-based steady-state solar simulator with Class AAA performance for testing larger solar modules, enabling coverage of high-power modules used in modern PV manufacturing.
• PV Import Testing at Port of Rotterdam PV import testing service at the Port of Rotterdam, operated through OdinSpire under the Eternal Sun brand. Provides quality assurance of solar modules entering the European market for solar installers, EPCs, utility companies, and solar power producers.
• PV Import Testing at Port of Valencia PV import testing service at the Port of Valencia for quality assurance of solar modules imported into Europe, supporting solar installers, EPCs, utility companies, and solar power producers.
• PV Factory Inspections in China and South-East Asia Factory inspections and quality verification services in China and South-East Asia for solar module manufacturers and buyers, supporting pre-shipment and pre-import quality assurance.
• WAVELABS Eternal Sun Cell Testing Platform Dedicated solar cell testing platform for precise, reliable results at every scale, leveraging WAVELABS LED-projection-based solar simulators. Provides cell-level measurement solutions complementing Eternal Sun's module-level simulators.

Quantifiable outcome

• A+A+A+ class illumination according to IEC 60904-9 ed. 3
• +4 more outcomes

Named customers4 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

Feature5 records

Partnerships

Two partnerships are on record, tiered core.

• WAVELABScoreStrategic or Co-development Partner · 9 June 2025German company that develops LED-based solar simulators for solar cell measurement. Key assets were acquired by Eternal Sun, forming a new subsidiary called WAVELABS Eternal Sun based in Leipzig. The combined entity offers a full spectrum of solar testing technology solutions.
• OdinSpirecoreImplementation/ SI/ Consulting PartnerPartner providing PV import testing services at the port of Rotterdam under the Eternal Sun brand

Scale indicators2 records

Recent moves7 records

Expansion highlights6 records

Direct peers

• Pasan SA (Meyer Burger): Pasan (now part of Meyer Burger) supplies high-speed Xenon flash solar simulators for cell and module IV testing under IEC standards, making it a direct competitor in the same A+A+A+ flash testing category that Eternal Sun's SPIRE products address.
• EKO Instruments: Japanese manufacturer of solar radiometers, pyranometers, and solar simulators used for PV module characterization and outdoor performance testing; overlaps with Eternal Sun's laboratory-grade solar metrology offering.
• Hainan Dr. Laser Optoelectronics Technology: Chinese supplier of solar cell and module testing equipment, including IV testers and sun simulators; competes with Eternal Sun in the China and Southeast Asia manufacturing customer base.
• Kipp & Zonen (OTT HydroMet): Dutch-based maker of solar radiation measurement instruments (pyranometers, pyrheliometers) that complement or overlap with solar simulator calibration and PV performance measurement workflows served by Eternal Sun.
• Strama-MPS: German provider of automated production and testing systems for solar cells and modules, including inline IV testers — directly comparable to Eternal Sun's manufacturing-line flasher business.
• ReRa Solutions: Dutch independent PV testing and consulting firm offering characterization, certification support, and quality assurance services — directly comparable to Eternal Sun's PV testing and inspection services arm.
• Sciencetech: Canadian manufacturer of solar simulators (steady-state and pulsed) for research and PV applications, overlapping with Eternal Sun's laboratory product lines targeting PV research groups.

Broad incumbents

• Atlas Material Testing Solutions: A larger, established player in weathering and solar exposure testing (including PV durability testing) — adjacent to Eternal Sun's metrology business with broader scope across materials and automotive.
• Meyer Burger Technology: Swiss-headquartered solar equipment manufacturer with a broader portfolio of cell-to-module production tools, including Pasan flash testers; overlaps with Eternal Sun in test equipment but at much larger scale and product breadth.
• Quantum Design: US-based scientific instrument maker supplying solar simulators and materials characterization systems for research labs, adjacent to Eternal Sun's high-end research customer segment but with a much wider product portfolio.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks6 records

Key highlights6 records

Customer concentration

• Xx.com/EternalSunNL
• LinkedInlinkedin.com/company/eternal-sun

Revenue estimate

Valuation estimate

Number of profiles

Profiles3 records

Subsidiaries1 record

Funding overview

Funding rounds3 records

Investors2 records

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

M&A2 records

Investments

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

Frequently asked questions about Eternal Sun