Researchers in Australia are working on a way to lower the cost of producing solar thermal energy by as much as 40% with the help of shatterproof rear-view mirrors originally designed for cars.
That could be huge for agriculture and industrial facilities which need large amounts of heat for large-scale processes at temperatures between 212 - 754 °F (100 - 400 °C). That addresses food production, drying crops, grain and pulse drying, sterilizing soil and treating wastewater on farms; industrial applications include producing chemicals, making paper, desalinating water, and dyeing textiles.
A quick refresher in case you're out of the loop: solar thermal energy and conventional solar energy (photovoltaic) systems both harvest sunlight, but they work in fundamentally different ways. Solar thermal setups capture the Sun's heat rather than its light, use reflectors to concentrate sunlight onto a receiver, and convert solar radiation directly into heat energy. This heat can be used directly for heating buildings, water, or the aforementioned industrial processes.
A team at the University of South Australia (UniSA) is using plastic mirrors developed at UniSA to be shatterproof, flat-packable, 50% lighter than glass counterparts, and easier to design and assemble into rear view wings for new vehicles. The plastic in question is a commonly available material, but uses special coatings to be as reflective as a regular mirror. Here's a promo clip highlighting the mirrors' capabilities:
UniSA's pilot project will see two models each made up of 16 coated mirror panels with a special multilayer aluminum-silica reflective coating to help generate thermal energy at those high temperatures. This setup will be tested at Charles Sturt University's Vineyard of the Future, a hub for innovating in wine production processes in Australia.
"We’re seeing record fossil fuel prices and increasing pressure for industries to decarbonize," said UniSA professor Colin Hall, who invented the plastic mirror coating technology. "This concentrated solar thermal (CST) solution is uniquely suited to Australia’s hot, dry climate and offers a viable pathway to zero-emissions process heat.”
This follows a CST project in China from last year, which saw two towers surrounded by mirrors set in overlapping concentric circles that can follow the path of the Sun and reflect light to either tower – making for efficiency improvements of 24%.
"Industrial process heat accounts for a staggering 25% of global energy use and 20% of CO2 emissions," noted UniSA project lead Dr. Marta Llusca Jane. Innovations like these could help us meet those demands without stressing the environment a whole lot.
Source: University of South Australia