A team of researchers at the Massachusetts Institute of Process (MIT) has discovered a new scalable manufacturing technology for producing ultrathin and light solar cells that can be swiftly and readily inserted into any surface.
These tough, flexible solar cells are connected to a strong, lightweight fabric and are far thinner than a human hair, making them easy to instal on a permanent surface. They may be carried and swiftly deployed in isolated areas to provide help in an emergency, or as a wearable power fabric, they can deliver energy on the run. They are made of semiconducting inks and printed processes that can be scaled up to large-area production in the future, and they generate 18 times more power per kilogramme than regular solar panels.
Because these solar cells are so light and thin, they may be glued to a variety of surfaces. They may, for example, be attached to tents and tarps used in disaster relief operations, incorporated into a boat’s sails to provide power while at sea, or used on drone wings to improve their flying distance. This portable solar technology requires minimum installation and integrates well into built environments.
“In most cases, just the power conversion efficiency and cost in dollars per watt are used to evaluate new solar cell technology. Integrability, or the ease with which new technologies may be adopted, is also critical. The current work is inspired by the integrability provided by thin solar textiles. Given the present urgent need for new carbon-free energy sources, we are working to accelerate the adoption of solar energy, says Vladimir Bulovi, Fariborz Maseeh Chair in Emerging Technology, director of MIT.nano, and leader of the Organic and Nanostructured Electronics Laboratory (ONE Lab).
Bulovi collaborates on the work with co-lead authors Mayuran Saravanapavanantham, a graduate student in electrical engineering and computer science at MIT, and Jeremiah Mwaura, a research scientist at the MIT Research Laboratory of Electronics. The work was published in the journal Small Methods.
Solar Streamlined
Because traditional silicon solar cells are fragile, they must be enclosed in a hefty, thick aluminium frame, limiting where and how they may be employed.
Six years ago, the ONE Lab team employed a novel class of thin-film materials that were so light they could sit on top of a soap bubble to produce solar cells. However, sophisticated vacuum-based procedures were utilised to make these incredibly thin solar cells, which may be costly and difficult to scale up.
The purpose of this project was to develop fully printable thin-film solar cells using ink-based materials and scalable manufacturing processes.
Solar cells are made with nanomaterials in the form of printable electronic inks. While working in the MIT.nano clean room, they coat the solar cell structure with a slot-die coater, which deposits layers of electrical components onto a ready, releasable substrate only 3 microns thick. The solar module is completed by screen printing an electrode onto the framework, a technique used to add images to silkscreened T-shirts.
The printed module, which is around 15 microns thick, may then be peeled away from the plastic substrate, resulting in a lightweight solar device.
However, because they are easily ripped and difficult to control, such small, freestanding solar modules are challenging to deploy. On address this challenge, the MIT team sought for a thin, flexible, and robust substrate to which they could attach the solar cells. Fabrics were chosen as the finest alternative since they provide mechanical strength and flexibility while adding little weight.
They found the ideal material: Dyneema, a composite fabric with a weight per square metre of only 13 grammes. The fibres used to produce this fabric are so strong that they were used as ropes to lift the sinking cruise ship Costa Concordia from the bottom of the Mediterranean Sea. They adhere the solar modules on sheets of this fabric with a small layer of UV-curable glue.
Even while it may appear easier to simply print the solar cells directly on the fabric, the range of suitable fabrics or other receptive surfaces would be limited to those that are chemically and thermally compatible with all of the manufacturing methods necessary to make the devices. According to Saravanapavanantham, our technique separates the manufacture of solar cells from their integration into final goods.
Superior to Conventional Solar Cells
When freestanding, the device could generate 730 watts of power per kilogramme and around 370 watts per kilogramme when placed to the high-strength Dyneema fabric. This is roughly 18 times the power per kilogramme of conventional solar cells.
A typical rooftop solar installation in Massachusetts has a capacity of around 8,000 watts. According to the creator, our fabric photovoltaics would only add about 20 kilogrammes (44 pounds) to the weight of a home’s roof to produce the same amount of power.
