CUSTOM-ART · Project

Flexible, Earth-Abundant Solar Panels That Replace Building Facades and Urban Furniture

energyTestedTRL 7

custom-art-h2020.eu

Imagine if your office building's windows, walls, or even park benches could quietly generate electricity — without relying on rare or toxic metals. That's what CUSTOM-ART worked on: thin, flexible solar panels made from kesterite, a material built from common elements like copper, zinc, and tin. These panels can be bent onto curved surfaces, made semi-transparent for windows, and stuck on with a reversible adhesive so they can be swapped out later. The goal was to hit 20% efficiency at the cell level while lasting over 35 years — all at under 75 euros per square meter.

By the numbers

20%

Target cell conversion efficiency

16%

Target module conversion efficiency (monolithically interconnected)

35 years

Extrapolated module lifetime from mechanical aging tests

< 75 €/m²

Target production cost

Consortium partners across 10 countries

SMEs in the consortium

48%

Industry partner ratio

The business problem

What needed solving

Buildings account for roughly 40% of energy consumption in Europe, and regulations increasingly demand near-zero energy performance. Current building-integrated solar options either rely on scarce, expensive elements (indium, gallium, tellurium) or toxic materials (cadmium), creating supply chain risk and regulatory headaches. Architects and developers need flexible, aesthetically adaptable solar solutions that can integrate into facades, windows, and urban furniture without compromising design or long-term sustainability.

The solution

What was built

The consortium built kesterite thin-film solar cell demonstrators achieving up to 20% efficiency (cell) and 16% efficiency (sub-module with monolithic interconnection), on both flexible polymer and steel substrates as well as semi-transparent polymer. They also developed a reversible adhesive system for building integration, validated 35-year durability through accelerated aging tests, and confirmed real-world performance through 6-12 months of field testing with continuous monitoring.

Audience

Who needs this

Commercial property developers pursuing net-zero energy building certificationsCurtain wall and facade system manufacturers looking to add energy-generating glass productsUrban furniture companies (bus shelters, benches, signage) wanting integrated solar powerArchitects specializing in sustainable building design and renovationMunicipal smart city departments deploying self-powered urban infrastructure

Business applications

Who can put this to work

Commercial Real Estate & Property Development

enterprise

Target: Property developers and building owners pursuing net-zero energy certification

If you are a property developer struggling to meet near-zero energy building requirements without sacrificing architectural aesthetics — this project developed flexible and semi-transparent kesterite solar modules that integrate directly into facades and windows. They target 20% cell efficiency and 16% module efficiency with production costs below 75 €/m², using only earth-abundant, non-toxic materials. The reversible adhesive system means modules can be replaced or upgraded without damaging the building envelope.

Urban Infrastructure & Smart Cities

any

Target: Municipalities and urban furniture manufacturers

If you are a city authority or street furniture manufacturer looking to power bus shelters, benches, or signage sustainably — this project built flexible PV modules on polymer and steel substrates designed for product-integrated photovoltaics (PIPV). The modules are engineered for 35-year durability and can conform to curved surfaces typical of urban furniture designs. Field testing validated real-world performance over 6-12 months of continuous monitoring.

Glass & Facade Manufacturing

mid-size

Target: Curtain wall and glazing system manufacturers

If you are a facade or glazing manufacturer looking to add energy-generating capability to your product line — this project developed semi-transparent kesterite solar modules on polymer substrates that can replace conventional glass panels. Unlike competing technologies using cadmium or indium, these use only abundant, non-toxic elements, simplifying regulatory compliance. The target production cost below 75 €/m² positions these as competitive additions to premium facade systems.

Frequently asked

Quick answers

What would these solar modules cost compared to conventional BIPV?

The project targeted production costs below 75 €/m², which is competitive with existing thin-film BIPV technologies. Because kesterite uses earth-abundant elements (copper, zinc, tin, sulfur) instead of scarce indium, gallium, or tellurium, raw material costs are structurally lower and less exposed to supply chain volatility.

Can this technology scale to industrial production volumes?

The project brought kesterite BIPV technology from TRL 4-5 to TRL 7 (system prototype demonstrated in operational environment). With 10 industry partners in the 21-member consortium — including 7 SMEs — and demonstrated monolithically interconnected sub-modules, the technology is positioned for pilot manufacturing but has not yet reached full commercial production scale.

What is the IP and licensing situation?

Based on available project data, the consortium of 21 partners across 10 countries likely generated shared IP. Licensing arrangements would need to be negotiated with the coordinator (IREC, Spain) or the specific industrial partners involved. The reversible adhesive prototype and specific cell architectures may carry separate IP.

How long do these modules actually last?

Mechanical aging and accelerated lifetime testing demonstrated compatibility with a 35-year extrapolated lifetime. Additionally, packaged modules underwent 6-12 months of real-world field testing with continuous power and efficiency monitoring, validating durability claims beyond laboratory conditions.

How efficient are these panels compared to what's on the market today?

The project targeted 20% conversion efficiency at the cell level and 16% at the sub-module level with monolithic interconnection. These figures are competitive with mainstream thin-film technologies like CIGS, but achieved using only non-toxic, earth-abundant materials — a significant differentiator for green building certifications.

Do these modules meet building codes and safety regulations?

The project used standard industry mechanical aging tests (bending, stretching) for packaging validation. The exclusive use of non-toxic, earth-abundant elements avoids the regulatory complications associated with cadmium-based competitors. Based on available project data, specific building code certifications would need to be confirmed with the consortium.

Can I integrate these into existing building renovation projects?

Yes — the reversible adhesive system was specifically developed for retrofit applications. Modules can be bonded to existing surfaces and later debonded without damage, making them suitable for renovation projects where permanent modifications are undesirable. Both flexible (polymer and steel substrate) and semi-transparent options provide design versatility.

Consortium

Who built it

The CUSTOM-ART consortium is unusually strong for commercialization: 21 partners spanning 10 European countries, with a 48% industry ratio (10 industrial partners including 7 SMEs). This near-equal split between industry and research institutions signals genuine market pull, not just academic curiosity. The geographic spread across major European markets (Germany, France, Italy, Spain, Sweden, UK) provides direct access to diverse building codes, energy markets, and construction industries. Having 7 SMEs involved means the technology development was shaped by companies that need practical, cost-effective products — not just publishable results. The coordinator IREC (Catalonia) is a well-established energy research institute with strong ties to Spanish and European solar industry.

FUNDACIO INSTITUT DE RECERCA EN ENERGIA DE CATALUNYACoordinator · ES
ECO RECYCLING SOCIETA A RESPONSABILITA LIMITATAparticipant · IT
CRYSTALSOL OUparticipant · EE
INTERUNIVERSITAIR MICRO-ELECTRONICA CENTRUMparticipant · BE
UPPSALA UNIVERSITETparticipant · SE
CENTRE TECHNIQUE INDUSTRIEL DE LA PLASTURGIE ET DES COMPOSITESparticipant · FR
AGENZIA NAZIONALE PER LE NUOVE TECNOLOGIE, L'ENERGIA E LO SVILUPPO ECONOMICO SOSTENIBILEparticipant · IT
RESCOLLparticipant · FR
IMRA EUROPE SASparticipant · FR
ACT SISTEMAS SLthirdparty · ES
ATECH ADVANCED SOLUTIONS SAparticipant · ES
UNIVERSITAT POLITECNICA DE CATALUNYAthirdparty · ES
HELMHOLTZ-ZENTRUM BERLIN FUR MATERIALIEN UND ENERGIE GMBHparticipant · DE
OXFORD BROOKES UNIVERSITYparticipant · UK
RESCOLL MANUFACTURINGthirdparty · FR
CARL VON OSSIETZKY UNIVERSITAET OLDENBURGparticipant · DE
SUNPLUGGED - SOLARE ENERGIESYSTEME GMBHparticipant · AT
TALLINNA TEHNIKAÜLIKOOLparticipant · EE
EIDGENOSSISCHE MATERIALPRUFUNGS- UND FORSCHUNGSANSTALTparticipant · CH

How to reach the team

Contact IREC (Fundació Institut de Recerca en Energia de Catalunya) in Barcelona, Spain — the coordinating research institute. SciTransfer can facilitate introductions.

Order a report on this consortium See FUNDACIO INSTITUT DE RECERCA EN ENERGIA DE CATALUNYA profile →

Next steps

Talk to the team behind this work.

Want to explore kesterite BIPV for your buildings or product line? SciTransfer can connect you directly with the CUSTOM-ART team and provide a tailored technology brief. Contact us for a matchmaking introduction.

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