SA academics help produce cheap solar energy via windows

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Academics Lucas Erasmus (left) and professor Hendrik Swart (right).
Academics Lucas Erasmus (left) and professor Hendrik Swart (right).

Academics in South Africa and Belgium have produced a working model of a new type of window glass – a transparent solar panel – which will generate cheap power from the sun in a clean way.

The working model proves the viability of the process which now needs to be refined, made more efficient and brought to the market. It is hoped this will be achieved within a decade.

The joint research, being done by academics from the University of the Free State (UFS) in SA and Ghent University in Belgium, will have the capacity to generate power cheaply from the sun to power homes, factories and cities.

The ambitious project becomes the latest project to support government’s desire to find alternative energy sources.

SA’s road map for future electricity mix, the draft Integrated Resource Plan, recognises the importance of alternative energy.

The Department of Energy has already signed 27 renewable energy projects with independent power producers. These deals are reportedly valued at about R58 billion.

Analysts estimate the private sector has invested more than R200 billion in renewable energy in SA to date.

Academics, professor Hendrik Swart and Lucas Erasmus from the UFS, have now entered the fray, doing joint research with Ghent University in Belgium, to find solutions for energy production.

The two universities entered into an agreement recently for this research into electricity generation. The research, driven by the UFS, was prompted by ever-rising electricity prices and growing demand for electricity production.

Swart, who is senior professor in the UFS Department of Physics and chairman of the South African Research Chairs Initiative in Solid State Luminescent and Advanced Materials, says: “An innovation like this, which can help to replace traditional means of carbon-based fuel for power generation in our daily lives, would be hugely welcome.

“The idea is to develop glass that is transparent to visible light, just like the glass you find in the windows of buildings, motor vehicles and mobile electronic devices. However, by incorporating the right phosphor materials inside the glass, the light from the sun that is invisible to the human eye (ultraviolet and infrared light) can be collected, converted and concentrated to the sides of the glass panel where solar panels can be mounted.

“This invisible light can then be used to generate electricity to power buildings, vehicles and electronic devices. The goal is therefore to create a type of transparent solar panel.”

Swart says this technology can be implemented in the building environment to meet the energy demands of the people inside the buildings.

“The technology is also good news for the 4.7 billion cellphone users in the world, as it can be implemented in the screens of cellphones, where the sun or the ambient light of a room can be used to power the device without affecting its appearance.”

Another possible application is in electric cars, where the windows can be used to help power the vehicle.

Erasmus, who works with Swart, explains: “We are also looking at implementing this idea into hard, durable plastics that can act as a replacement for zinc roofs. This will allow visible diffused light to enter housing and the invisible light can then be used to generate electricity. The device also concentrates the light from a large area to the small area on the sides where the solar panels are placed; therefore, reducing the number of solar panels needed, and in return, reducing the cost.”

He says it is envisaged the technology will take about a decade to refine and implement. This study is ongoing, and UFS is experimenting and testing different materials in order to optimise the device in the laboratory. It then needs to be upscaled in order to test it in the field. “It is truly the technology of the future.”

The UFS envisages the end result of this research will provide an attractive solution to address the energy demands of buildings, electric motor vehicles and mobile electronics without affecting their appearance.

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