Solar power is a great alternative energy source, but it’s unfortunately a rather expensive one. However, researchers at MIT are working on a new and less-expensive way to make solar cells which involves printing them directly on to fabric or paper.
We’re not talking about any fancy paper or fabrics. The MIT researchers discovered the printing process works on just about any paper, from regular printer paper, to tissue paper, and even to already-printed newspaper. However, printing the cells is not as simple. It must be done in a vacuum-tight room where the special “ink” is deposited on the paper. According to an article by MIT’s David L. Chandler, the process is almost as cheap and as easy as printing a photo on your inkjet.
It’s a much easier method than the current one, which needs super high-temperature liquids at several hundred degrees Celsius to create the cells. The new method uses vapors and lower temperatures at less than 120 degrees Celsius. According to Chandler, these “gentle conditions” are what makes it possible to use untreated paper as the substrate.
The substrate of the current method is usually glass and requires a number of other components that are expensive and result in a heavy, rigid object – and that’s not even taking into account the installation costs. With paper or fabric being used as the new substrate, creating the solar cells is much less expensive. To create the cells, five layers of material have to be deposited on the paper in consecutive passes. Though it might sound complicated, Chandler said the basic process is pretty much the same as the one used to make the shiny silver lining in a bag of potato chips. So, if potato chips bag producers can do it on a large commercial scale for cheap, so can solar-cell printing.
The paper can be folded up, slipped into your pocket, unfolded, and will work as well as it did in the first place. The MIT researchers tested this by folding the printed material into a paper airplane. Professor of Electrical Engineering Vladimir Bulovic said the team has thoroughly tested the robustness of the technology. He said that the low weight of the paper substrate will let them create “scalable solar cells that can reach record-high watts-per-kilogram performance” This could open up a number of applications. For example, they could be used in remote developing countries where weight is a large factor in how many cells can be delivered. The paper can also easily be applied to a wall or to window shades to make it super easy to install your own solar panels.
The team tested it under the extreme heat of a laser printer and the cells still worked. Also, they tested cells they created last year, which means they have a long shelf life. There’s no word on how long of a shelf life they actually have, since the experiment has only been going for so long. Even so, a year is fine if replacing them just involves printing some more sheets out. The paper can also be coated with lamination materials, so you can place them outside and not worry about water damaging the cells.
The one drawback is that, currently, the paper-printed solar cells have about a 1 percent efficiency. However, the team feels it can drastically increase that with more fine-tuning. Bulovic said that the cells are currently good enough to power a “small electric gizmo.”
Could this be a new way to give our battery-hungry smartphones a little boost as they start to fade when we’re on the go? Or eventually will we all be rolling out laminated paper sheets on our roofs for years of free energy?