Fifteen years ago, Dr Anita Ho-Baillie’s dad remarked that there should be a way to put solar cells on windows.
Today this vision is set to become a reality, with Ho-Baillie now working on a high-insulating energy generating glass that promises to “revolutionise the architectural glazing market”.
“It stayed with me for several years,” she says. “It’s amazing that something my dad said as a throw away I’m now working on.”
Ho-Baillie, a senior research fellow in the Faculty of Engineering at UNSW, is partnering with University of Sydney’s Professor David McKenzie and Viridian Glass on the project, which involves integrating semi-transparent perovskite solar cells into a double-glazed vacuum-insulated window unit.
The project has received $365,000 in funding from the Australian Research Council Linkage Grant program, with the goal to create a high-performance glazing system that can mitigate heat gain in summer and heat loss in winter, while also controlling the entry of light and generating electrical energy in order to create, according to the research statement, “the ultimate energy solution for future cities”.
Ho-Baillie is well-known for her work with perovskites, the cheap, flexible and lightweight darling of the solar industry.
At the end of last year she gained international attention for breaking the world energy conversion efficiency record for perovskites, with a 12.1 per cent efficiency rating for a 16cm perovskite solar cell, up from 3.8 per cent in 2009. With thousands of researchers around the world working on the technology, she says efficiency could double in the next year or so.
Perovskites are expected to transform the built environment sector, having the ability to be spray-coated, printed or painted on almost any surface imaginable.
It may also be necessary for meeting a global goal of net zero buildings by 2050, with a pitt&sherry report into net zero high-rise buildings released last year naming building integrated photovoltaics (BIPV) – particularly as part of glazing units – as key to this challenge.
Ho-Baillie says different levels of transparency can be created with the perovskites, depending on the power rating needed for the facade (the more transparent, the less energy generated). The perovskites can also be tuned to display different colours, which could have both functional and aesthetic uses. Having building fabrics with multiple functions, she says, should increase a building’s value.
One problem with perovskites has been their durability, as they are prone to fluctuating temperatures and moisture, meaning their lifespan is only a few months without protection.
The excitement around this current project is that not only will the vacuum-sealed double-glazing unit – pioneered by the University of Sydney and Professor McKenzie – provide an extremely high level of insulation by removing thermal bridges, it will also work to protect the perovskite layer from moisture damage.
“It serves a purpose of making them longer lasting,” Ho-Baillie says.
Durability of perovskites is already progressing in leaps and bounds.
“The durability is improving as we speak. A few years ago [the cells] would last for a month; now it’s more than a year. With so many people working in the field, a lot of the problems can be solved.”
Ho-Baillie won’t be drawn on when the technology will become commercially available, as it’s still early days. However, the universities are actively engaging with Viridian to make sure the technology can be low-cost, viable and replicable.
Watch this space.