UPC Spain Confirms Solaires' Photovoltaic Power Advantage

Solaires Team | Victoria, B.C | March 31st, 2025

Solaires’ PVModules absorb more indoor light, with less materials, than all economically viable competition, according to a new independent paper published in IEEE Transactions on Instrumentation and Measurement. With LED lights, the most common household light source in North America, Solaires’ PVModules performed between 50 and 200 % better than their commercially available competition.

Researchers at the Universitat Politècnica de Catalunya (UPC) in Barcelona evaluated and compared commercially available indoor photovoltaic (IPV) modules from eleven companies making photovoltaics from crystalline silicon, amorphous silicon, organics, GaAs, and perovskite.

Solaires’ PVModules absorb more indoor light, with less materials, than all economically viable competition, according to a new independent paper published in IEEE Transactions on Instrumentation and Measurement. With LED lights, the most common household light source in North America, Solaires’ PVModules performed between 50 and 200 % better than their commercially available competition.

Researchers at the Universitat Politècnica de Catalunya (UPC) in Barcelona evaluated and compared commercially available indoor photovoltaic (IPV) modules from eleven companies making photovoltaics from crystalline silicon, amorphous silicon, organics, GaAs, and perovskite.

This paper was published as a part of the CELISA project , funded by Spain’s Agencia Estatal de Investigación , to investigate the challenges and opportunities of powering smart devices and IoT with small photovoltaics. As indoor photovoltaics is a young market, few measurement or quality standards exist, with the IEC only recently releasing recommendations for how to measure, and prepare to measure, indoor photovoltaics. Additionally, while organisations like NREL maintain databases of outdoor photovoltaic performance, no such database exists for indoor photovoltaics. As such, consumers, investors, and customers are often left to the PV manufacturers themselves to supply performance and comparative data. The purpose of this specific article is to directly compare the performance of commercial devices with multiple lighting conditions in an industry where performance is dependent on self-reporting by companies which can pick and choose their testing conditions.

The research group at UPC built an automated testing platform where modules were evaluated in a dark box to prevent ambient light from skewing test results. In the dark box, four light sources with tuneable output power were used; specifically  warm LED (2800 K), cold LED (4800 K), compact fluorescent light (CFL), and halogen incandescent bulbs. Additionally, the testing system included a source and measurement unit to measure current and voltage from illuminated PV modules.

While crystalline silicon modules are designed for outdoor use, and performed poorly with LED and CFL lighting, the other technologies were designed for indoor use and all but one performed worse - usually less than 50% of the power density - than PVModules. Only the GaAs module outperformed Solaires’ technology, though the authors note that GaAs technologies are prohibitively expensive (~100x more expensive than other technologies!) outside of highly niche applications where cost is a minor factor.

In a comparison of twelve different photovoltaic modules from eleven different companies, Solaires is proud to have more than doubled the power generation of incumbent amorphous silicon companies; nearly doubled co-emerging organic PV companies; and doubled the performance of our perovskite competitors. The comparison was done with light intensities ranging from 100 to 1000 lux and using “warm” LED, “cold” LED, CFL, and halogen bulbs. In both LED and CFL scenarios, Solaires trailed only the GaAs module at “standard” conditions (1000 lux, 25 °C), performing best with warm-LED, generating 72 μW / cm2, while other perovskites produced less than 40 μW / cm2, and silicon modules produced ~ 25 μW / cm2.

Of particular note, when using halogen bulbs, an incandescent light largely being phased out worldwide, Solaires PVModules perform even better than the GaAs module, and only trail the crystalline silicon modules tuned for the outdoors. This is because halogen bulbs have a very similar light spectrum to natural sunlight . The upside of this is that while PVModules are tuned to generate electricity from LED and CFL sources, they still perform very well in outdoor - and outdoor adjacent - conditions, opening the door for hybrid applications like headphones and power banks.