IMPRESSIVE · Project

Fully Transparent Solar Windows That Generate Electricity Without Blocking Light

energyTestedTRL 5

impressive-h2020.eu

Imagine if your office windows could generate electricity while still looking completely clear — no tinting, no color, just normal glass that happens to be a solar panel. This project figured out how to harvest the invisible parts of sunlight (ultraviolet and infrared) while letting all the visible light pass straight through. They stacked two types of solar cells together like a sandwich — one catches UV, the other catches infrared — and built a working transparent module about the size of a large tablet. The goal: 14% energy conversion efficiency from something you literally cannot see is working.

By the numbers

14%

Target power conversion efficiency for fully transparent solar cells

25 years

Target lifetime for transparent PV modules

200 x 300 mm

Size of demonstrated transparent tandem PV module

55%

Minimum average visible transmittance (fully see-through)

Consortium partners across 4 countries

44%

Industry partner ratio in the consortium

The business problem

What needed solving

Buildings consume enormous energy but their largest surface — windows — generates nothing. Conventional solar panels are opaque and ugly on facades, forcing architects to choose between daylight and energy production. Property developers pursuing net-zero targets need a way to generate clean energy from glass surfaces without compromising building aesthetics or natural light.

The solution

What was built

The consortium built a fully transparent tandem photovoltaic module (200 x 300 mm) combining a UV-perovskite solar cell with a NIR-dye-sensitized solar cell, achieving over 55% average visible transmittance. They also completed life cycle assessment, cost analysis, and a post-project commercialization roadmap.

Audience

Who needs this

Architectural glass and facade manufacturers looking for next-generation smart glass productsCommercial real estate developers pursuing LEED, BREEAM, or net-zero building certificationsSolar energy companies wanting to expand beyond rooftop panels into building-integrated PVGreen building consultants and energy retrofit specialistsGreenhouse operators seeking energy-generating transparent roof panels

Business applications

Who can put this to work

Commercial Real Estate & Green Building

enterprise

Target: Property developers, building owners, and facility managers pursuing net-zero or green building certifications

If you are a commercial property developer trying to meet net-zero energy targets — this project developed fully transparent solar modules (200 x 300 mm, over 55% visible light transmission) that turn ordinary windows into power generators. Instead of choosing between natural daylight and on-site energy production, you get both. The technology targets 14% power conversion efficiency with a 25-year lifetime, potentially offsetting a building's energy costs without sacrificing aesthetics.

Glass & Facade Manufacturing

mid-size

Target: Architectural glass manufacturers and curtain wall system integrators

If you are a glass manufacturer looking for the next high-margin product line — this project created a transparent tandem solar cell that can be integrated into building glass. One consortium partner already sells dye-sensitized solar cell modules for building-integrated PV, and another has a pilot production line. The 200 x 300 mm module format and over 55% average visible transmittance make it compatible with standard facade engineering requirements.

Renewable Energy & Solar

any

Target: Solar PV companies and energy solution providers seeking differentiated products beyond rooftop panels

If you are a solar energy company whose products compete on price alone — this project offers a technology that opens entirely new surfaces for solar deployment: windows, skylights, and glass facades. Unlike conventional panels, these transparent cells target 14% efficiency while remaining colorless. With a projected 25-year lifetime and a cost roadmap developed within the project, this could expand your addressable market beyond rooftops.

Frequently asked

Quick answers

What would transparent solar windows cost compared to regular building glass?

The project included a dedicated cost study and roadmap (WP7) for post-project commercialization. Based on available project data, specific per-unit pricing is not published, but life cycle assessment and cost analysis were core deliverables designed to establish a viable price point for the construction market.

Can this be manufactured at industrial scale?

The consortium upscaled components to a 200 x 300 mm transparent PV module, and one partner (UTV) already operates a pilot production line for building-integrated dye-sensitized solar cells. Another partner (HG) is the first company commercially selling DSSC modules for building-integrated PV. These are concrete steps toward industrial-scale manufacturing.

What is the IP situation — can I license this technology?

The project is based on a patent that was being filed at the time of launch. IPR management was a dedicated work package (WP1), handled in coordination with InnoEnergy. Licensing inquiries would need to go through the consortium, likely led by the coordinator CNRS and the industrial partners.

How efficient are these transparent solar cells really?

The project targeted 14% Power Conversion Efficiency while maintaining full transparency (over 55% average visible transmittance). For context, conventional opaque solar panels achieve 20-22%, so 14% from something completely see-through represents a significant energy yield from otherwise unused building surfaces.

How long do these transparent solar modules last?

The project targeted a lifetime of over 25 years, which aligns with standard building component warranties. Stability testing was a dedicated work package (WP5), and the consortium includes partners with deep expertise in durability assessment of both perovskite and dye-sensitized solar cells.

Does this meet building regulations and standards?

Based on available project data, the life cycle assessment (WP7) and the involvement of building-integrated PV specialists suggest regulatory compliance was considered. The 55% average visible transmittance target was specifically designed for integration into building facades and windows. Specific certifications would need to be confirmed with the consortium.

Who in the consortium can actually produce and deliver this?

HG is already the first company selling DSSC modules for building-integrated PV commercially. UTV has developed a pilot production line for building-integrated DSSC. These two industrial partners are the most likely routes to product availability. The consortium also includes InnoEnergy involvement for business strategy.

Consortium

Who built it

The 9-partner consortium across France, Switzerland, Italy, and the Netherlands brings together world-class solar cell research with real manufacturing capability. CNRS coordinates, EPFL leads perovskite solar cell development, and critically, the consortium includes companies that are already in the building-integrated PV market — HG is the first company commercially selling DSSC modules, and UTV operates a pilot production line. With 4 industrial partners (44% of the consortium) including 2 SMEs, this is not a purely academic exercise. The involvement of InnoEnergy for business strategy and EQY for market uptake suggests the consortium was designed with commercialization in mind from the start.

CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRSCoordinator · FR
UNIVERSITA DEGLI STUDI DI ROMA TOR VERGATAparticipant · IT
UNIVERSITE DE PICARDIE JULES VERNEthirdparty · FR
UNIVERSITA DEGLI STUDI DI TORINOparticipant · IT
ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNEparticipant · CH
DE WILD-SCHOLTEN MARISKAparticipant · NL
EUROQUALITY SASparticipant · FR

How to reach the team

The project is coordinated by CNRS (France). Industrial partners HG and UTV are the most relevant contacts for commercial licensing or product inquiries.

Order a report on this consortium See CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS profile →

Next steps

Talk to the team behind this work.

Want an introduction to the IMPRESSIVE consortium for licensing transparent solar window technology? SciTransfer can connect you with the right partner — contact us for a matchmaking consultation.

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