How Class A+A+A+ solar simulators from EternalSun enable accurate IV-curve testing of PERC, HJT, Perovskite and bifacial modules — and why BUET, KUET and Bangladesh's growing solar quality-control sector need them.
Bangladesh installed substantial new solar capacity in 2025 and is on track to reach 20% of electricity from renewables by 2030 (~5,600–6,145 MW) under the Renewable Energy Policy 2025. Yet the country still lacks a nationally accredited PV module testing laboratory capable of certifying panels to IEC 61215 and IEC 61730 — the two international standards required for bankable solar projects. The result: imported modules are accepted on the basis of overseas test certificates alone, with no independent verification of performance under Bangladesh's specific climate conditions (high humidity, high ambient temperature, dust loading from the dry season). EternalSun solar simulators are the instrument of choice for closing this gap — and Vvon Technologies is the authorised supplier in Bangladesh.
A solar simulator is a laboratory instrument that replicates the spectral distribution, intensity and spatial uniformity of natural sunlight under standardised conditions (AM1.5G, 1000 W/m², 25°C cell temperature) — the reference conditions defined by IEC 60904-3. By exposing a solar cell or module to this controlled artificial sunlight and sweeping the load from open-circuit to short-circuit, the instrument measures the IV curve — the fundamental performance fingerprint of any PV device. From the IV curve, all key parameters are derived: open-circuit voltage (Voc), short-circuit current (Isc), maximum power point (Pmax), fill factor (FF) and efficiency (η). Without a calibrated solar simulator, none of these parameters can be measured accurately indoors.
EternalSun was founded in 2011 as a spin-off from Delft University of Technology (TU Delft) in the Netherlands — one of Europe's leading technical universities. The company's founders were PV researchers who built their own solar simulators for research and realised that no commercial instrument met the accuracy requirements of next-generation PV technologies (Perovskite, tandem, HJT). EternalSun now supplies simulators to leading research labs and module manufacturers in over 30 countries, including NABL-accredited labs in India (Mitsui Chemicals Solar PV Lab) and space PV testing facilities. The company's instruments are certified to IEC 60904-9 Edition 3 — the most stringent version of the solar simulator standard.
| Product | Type | Module Size | Spectrum | Key Application |
|---|---|---|---|---|
| LED Light Soaker | Steady-state LED | Mini to very large modules | 300–1200 nm, A+A+A+ | R&D, quality control, degradation testing |
| Mini LED Light Soaker | Steady-state LED | Up to 50×50 cm | Wide / extra-wide | Perovskite, tandem, thin-film R&D |
| Xenon Flasher | Pulsed xenon | Full-size modules | AM1.5G, Class A | Production-line IV testing |
| Temperature-Controlled Flasher | Pulsed xenon + temperature | Full-size modules | AM1.5G, Class A | Temperature coefficient measurement |
The LED Light Soaker is EternalSun's flagship product and the world's most widely used steady-state solar simulator for R&D. Its key advantages over conventional xenon-lamp simulators are: (1) spectral tunability — the multi-channel LED array can be tuned to match the spectral response of any PV technology, including tandem cells that require simultaneous illumination at two wavelengths; (2) long-term stability — LEDs maintain their spectral output for up to 36,000 hours without recalibration, compared to xenon lamps that degrade within 1,000 hours; (3) temperature control — an integrated temperature chamber maintains the module at 15–85°C for temperature coefficient measurements and accelerated degradation testing; and (4) A+A+A+ classification across all three IEC 60904-9 criteria (spectral match, spatial uniformity, temporal stability).
University PV research (BUET, KUET, RUET, SUST): Bangladesh's engineering universities are increasingly active in PV materials research — particularly thin-film, organic and Perovskite solar cells. A solar simulator is the essential instrument for characterising new absorber materials, optimising device architecture and measuring efficiency under standard test conditions. Vvon Technologies has already installed a solar simulator at KUET (Khulna University of Engineering & Technology) for the university's renewable energy research programme. National testing and certification: The Bangladesh Standards and Testing Institution (BSTI) and the Bangladesh Accreditation Board (BAB) are working towards establishing a nationally accredited PV module testing laboratory. An EternalSun simulator would be the centrepiece of such a facility, enabling Bangladesh to issue IEC 61215-compliant test reports that are accepted by international project financiers. Solar industry quality control: Module importers and EPC contractors can use a solar simulator to verify that imported modules meet their rated power — a critical step given the prevalence of under-performing modules in the market. A 5-minute IV test on arrival can detect power shortfalls of 5–15% that would otherwise go undetected until the plant underperforms.
IEC 60904-9 classifies solar simulators on three criteria, each rated A+, A, B or C: Spectral match — how closely the simulator's spectrum matches AM1.5G in each of six wavelength intervals (300–400, 400–500, 500–600, 600–700, 700–800, 800–1100 nm); Spatial non-uniformity — the variation in irradiance across the test area (A+ requires ≤1%); Temporal instability — the variation in irradiance over time during a measurement (A+ requires ≤0.5% for steady-state). A simulator rated A+A+A+ meets the highest classification on all three criteria simultaneously — the standard required for bankable power measurements and IEC 61215 type approval testing. EternalSun's LED Light Soaker achieves A+A+A+ classification, certified by independent accredited laboratories.
Vvon Technologies supplied and commissioned a solar simulator at Khulna University of Engineering & Technology (KUET) for the university's Department of Electrical and Electronic Engineering. The system is used for characterisation of PV cells and modules fabricated in the university's materials science laboratory, measurement of temperature coefficients for locally manufactured thin-film devices, and student training in PV measurement methodology. The KUET installation demonstrates the feasibility of operating a high-precision solar simulator in Bangladesh's tropical climate — with appropriate air-conditioning and humidity control, the instrument maintains its calibration and spectral stability year-round.
Vvon Technologies Limited is the authorised distributor and service partner for EternalSun in Bangladesh. We provide: pre-sales consultation and system specification; import clearance and customs documentation (HS code 9031.80.90 — optical measuring instruments); installation and commissioning by EternalSun-trained engineers; operator training in IV measurement methodology and IEC 60904 test procedures; and annual calibration verification. Lead time from order confirmation to commissioning is typically 16–20 weeks. Government universities and research institutes may procure through the annual development programme (ADP) budget under the 'Scientific Equipment' line item. Contact Vvon Technologies for a quotation and technical specification →