Birth of a new photovoltaic module technology optimised for urban environment

Newswise — Dr. Seung-il Cha's electric conversion material R&D team in Korea and Electrotechnology Research Institute (KERI) developed a 'New photovoltaic module technology' can perform self-power generation for urban environment.

Solar energy is an advocating renewable energy source as eco-friendly in South Korea, and with its own benefit as sunlight which is inexhaustible resource, currently utility-scale photovoltaics are installed incremental and widely in Southeastern-western area. But there's a critical aspect in terms of sharing and utilisation electricity in less supplying of the renewable energy’s transmission networks expected to transmit to the metropolitan or high demand area produced in installed area.

There are many attempts in order to produce and utilise electricity through photovoltaic power generation inner-urban. But in fact, it's an uneasy task since installation area (Spatially and structural) for applied infrastructure is complicated and diverse aspects concerns are inevitable. As an example, the photovoltaic power generation’s efficiency is sharply declined by partial shading; buildings, plants and so forth and eventually the repetition phenomenon of partial shading on the photovoltaic module, it clogs generated current (hot-spot)¹⁾ causing the ignition point. Therefore, urban photovoltaic module requires an advanced technology.
^{1) Ignition phenomenon (hot spot) by partial shading : When the shade shrouds the photovoltaic module partially, the generated current can come in but can't go out and cause the heat. The ignition point occurs by the given condition; partial shade, heat flocking and repetitions.}

The KERI's achievement is significant and with its new photovoltaic module development secures stretchable, security, efficiency and applicable to the urban environment. The research team restructures photovoltaic module's²⁾ materials and structures conventionally consists for more than 40 years.
^{2) The photovoltaic module's production commenced by 1955 and for space solar power utilisation, the module has been produced (tempered glass-EVA-Cell array- EVA-polymeric back sheet laminated structures) with low-price materials and processed since 1980. However, the previous module system lasts more than 40 years encounter issues such as material's durability, life span, possibility of fire risks, etc., since the solar power capacity demands high lately.}

The previous photovoltaic module was formed in laminated layers demands high cost with the tempered glass and plastics for solar cells protection. However, Dr.Seung-il Cha's team encapsulated each solar cells through silicone material and then electrical connected for glass-free applications, the team successfully restructures the outcome as flexible structures in module. The module's electrical connectivity is enabled to a hybrid way for the applications; the serial/parallel (more paths for the electricity to flow) combined. The team's idea changes the paradigm of the photovoltaic module obstinates for decades, therefore the world's first outcome of the KERI research is prominent performed for years of diligence.

The greatest advantage of the KERI's new photovoltaic module is stability of the power generation, security and stretchability. KERI module replaces previous flammable plastics to flame retardant materials appropriates in electric insulation and durability. Although, the hybrid (serial/parallel) structure effectively supports high power maintenance and prevents hot spot generations even though partial shading occurs on the photovoltaic module.

The module's stretchability is as highly portable as like paper folding, it allows diverse integrating applications, such in bench or lighting shield and etc., enables photovoltaic power generation. Although, the team fulfilled the module's design concerns can accelerate urban environmental applicability and adaptability by tessellation (mosaic) designs as on the pavement or bathroom tile alike.

The KERI improves the efficiency of the photovoltaic module with a new technology 'Helianthus (sunflower)'. It generates electricity by the module's structural optimisation and tracing solar location(Self-tracking) that is performable by attached shape memory alloy on arrayed solar cells. In this regard, the electric generation manifests 60% incremental per day compare to the previous flat modules. The KERI's photovoltaic module is the world's first solution and without particular installation of the system in the module but with the integral Self-tracking method.

"Our technology will be enabling our life better with our natural resource solar energy and self-electrogeneration throughout cities" and "It will be the significant milestone for the carbon neutrality and energy security strengthening as we see as national issues today." KERI's Dr.Seung-il Cha said.

This research has acknowledged by the British Royal Society of Chemistry(RSC) and published in 5 different research papers, include energy science journal's 'Sustainable Energy & Fuels' as a cover study³⁾. KERI aims the sustainable R&D to broaden solar power applications and to provide lighter and efficient solar modules for the future mobility such as automatic transportation (drone).
^{3) Impact Factor 6.084 / JCR’s Top 15.18%}

KERI is a national research institute affiliated with the Ministry of Science and ICT's National Research Council of Science & Technology (NST).