Solar glass for buildings, patented in Israel and the US

Facade glass that makes electricity from sunlight and from heat

Green Capsular Solution

We are developing a semi-transparent solar panel meant to replace ordinary building glass. The front layer turns sunlight into electricity. The layer behind it takes the heat that builds up in the panel and turns that into a second, separate power output, and a cooling coating on the back keeps it working after sunset.

Request the investor deck How it works

Commercial building with a semi-transparent amber solar glass facade

21.6%

combined efficiency (target)

~21%

of visible light passes through

The product

One panel, two ways of making power

Regular solar panels are opaque, so you can't glaze a building with them. We started from the opposite end. GCS is designed to be a window first: see-through enough for daylight, good looking enough for an architect, and producing electricity from both the light and the heat that hit it.

Semi-transparent solar glass, about 21% visible light through

Heat-to-electricity layer, patented technology

HOW IT WORKS

Two layers, two outputs

The top layer is a semi-transparent photovoltaic film. It turns sunlight into electricity and lets roughly 21% of visible light into the room.

Solar panels get hot, and normally that heat is just lost. In GCS a layer of laser-patterned pyrolytic graphite spreads it sideways and creates a temperature difference of about 20K across the panel. A thermoelectric layer converts that difference into a second, independent stream of electricity.

On the back there is a radiative cooling coating. At night it keeps the rear of the panel cooler than the front, so some output continues after dark.

21.6%

357W per panel, design target

That is above typical commercial silicon, in a panel that still passes about 21% of visible light and cools itself while it runs. The BIPV products we have looked at offer one of these, not all of them together.

Market

Nobody owns the BIPV market yet

The revised EU buildings directive (EPBD) phases in on-site solar requirements for new commercial buildings from 2026–27. That turns solar glass from something nice to have into something developers need, and in the semi-transparent, high-efficiency segment there is still no clear leader.

$29B

BIPV market todayGrowing 20–24% a year. The perovskite BIPV part of it is growing faster, 27–32% a year.

$150B

Projected for 2030Much of that growth is driven by the EPBD requirements.

$18B

Facade segment in 2030Glass facades, where a panel has to be both transparent and efficient.

3 in 1

Transparency, efficiency and heat recoveryWe haven't found a product on the market that combines all three.

BIPV market overview: manufacturing, supply chain and glass facades

Office and commercial facades

Goes in where standard glazing would. Offices keep their daylight and the facade produces power, which helps with EPBD compliance.

$18B by 2030

Data centers

Solar power, a lower cooling load and the extra thermoelectric output. Worth a lot to sites paying $10–50M a year for electricity.

$5B+ by 2030

Greenhouses

Enough light gets through for the plants to grow, so the same roof yields a crop and electricity.

$3–8B by 2030

Skylights and atriums

Glass roofs over train stations, malls and office lobbies that pay back part of the building's power bill.

$5B+ by 2030

Technology

What's inside the panel

Solar-thermoelectric panels have been tried before. They usually stall because the temperature difference collapses once the panel gets big, or because the materials are too expensive to scale. These are the three parts of our design that deal with that.

Thermal routing

The hard part of any solar thermoelectric panel is keeping a useful temperature difference across a large surface. Heat evens out, the gradient disappears and output drops to almost nothing. Our thermal routing layer is built to hold that gradient at full panel size, all day.

Patented, validated at an independent lab

Energy-conversion layer

A material system we arrived at after years of materials research. It converts heat to electricity near room temperature, which is where a building panel actually operates, and it can be produced industrially at a cost that makes commercial sense.

Patented, performance independently verified

Solar glass

We chose a photovoltaic absorber that beats standard commercial silicon on efficiency and still stays semi-transparent. It looks like tinted architectural glass, lets daylight in and produces more power per square meter than the BIPV products we compared it to. Long-term stability was tested under accelerated aging.

Certified efficiency, BIPV-grade durability tested

A cooler panel lasts longer

Because heat is pulled out of the photovoltaic layer while it works, the panel runs cooler. That raises PV efficiency and slows aging of the components. Other BIPV glass has no way to get rid of that heat.

How we compare

Against the BIPV glass products already on the market.

Product	PV efficiency	Light through (AVT)
Onyx Solar a-Si / CdTe, Spain	5–11%	15–20%
Heliatek Organic PV, Germany	8–10%	30–40%
Polysolar CIGS thin film, UK	11–13%	~25%
GCS Dual-layer PV + thermoelectric, Israel, patented	21.6% (target)	~21%