Apr 23 2020
According to Australian researchers, headed by members of the ARC Centre of Excellence in Exciton Science, semi-transparent solar cells that can be integrated into window glass are a real “game-changer” that can potentially redefine architecture, electricity generation, and urban planning.
Image Credit: Exciton Science.
The researchers have reported their study in the Nano Energy journal.
Headed by Professor Jacek Jasieniak from Monash University and Exciton Science, the scientists have successfully created state-of-the-art perovskite solar cells that produce electricity while enabling light to travel through. The team is currently exploring ways to integrate the novel technology into commercially available products with Australia’s largest glass manufacturer—Viridian Glass.
This latest technology will change windows into active power generators, possibly transforming the design of a building. According to the scientists, 2 m2 of solar window will produce almost as much electricity as a regular rooftop solar panel. The Australian Renewable Energy Agency (ARENA) has also funded the study.
Although semi-transparent solar cells are not a new concept, earlier designs did not work out well because they were inefficient, unstable, and very costly.
Professor Jasieniak and collaborators from Australia’s national science agency, CSIRO, and Monash University’s Materials Science and Engineering Department, adopted a different method.
The researchers selected an organic semiconductor that can be developed into a polymer and utilized it to substitute a typical solar cell component (called Spiro-OMeTAD). This exhibited extremely low stability since it develops an unnecessary watery coating. The organic semiconductor generated remarkable results.
Rooftop solar has a conversion efficiency of between 15 and 20%. The semi-transparent cells have a conversion efficiency of 17%, while still transmitting more than 10% of the incoming light, so they are right in the zone. It’s long been a dream to have windows that generate electricity, and now that looks possible.
Jacek Jasieniak, Professor, Exciton Science, Monash University
Dr Anthony Chesman, the study’s co-author and CSIRO research scientist, informed that the researchers are currently working to advance the manufacturing process.
“We’ll be looking to develop a large-scale glass manufacturing process that can be easily transferred to industry so manufacturers can readily uptake the technology,” Dr Chesman added.
For building residents and owners, solar windows will be a boon and will usher in new opportunities and challenges for planners, architects, engineers, and builders.
There is a trade-off. The solar cells can be made more, or less, transparent. The more transparent they are, the less electricity they generate, so that becomes something for architects to consider.
Jacek Jasieniak, Professor, Exciton Science, Monash University
Jasieniak added that the solar windows, tinted to the same level as today’s glazed windows available in the market, would produce around 140 W of electricity per square meter. The initial application could be done in multi-story buildings.
It is quite expensive to produce large-size windows that are installed in high-rise buildings. The extra cost of integrating the semi-transparent solar cells into these windows will only be marginal.
“But even with the extra spend, the building then gets its electricity free!” added Jacek.
Jacek continued, “These solar cells mean a big change to the way we think about buildings and the way they function. Up until now every building has been designed on the assumption that windows are fundamentally passive. Now they will actively produce electricity. Planners and designers might have to even reconsider how they position buildings on sites, to optimise how the walls catch the sun.”
Dr Jae Choul Yu, also from Exciton Science and Monash University and the study’s lead author, added that additional studies can lead to more efficiency gains.
Our next project is a tandem device. We will use perovskite solar cells as the bottom layer and organic solar cells as the top one.
Dr Jae Choul Yu, Study Lead Author, Exciton Science, Monash University
With regard to the launch of the first semi-transparent solar cells on the market, “that will depend on how successful scaling of the technology will be, but we are aiming to get there within 10 years,” Jacek informed.
Jatin Khanna, Operations Manager for Viridian Glass, stated, “The development of such solar windows presents an opportunity that could translate into the new glass innovations and technologies going forward.”