2014-08-19

Co.Exist

Spray-On Solar May Be Cheaper And More Eco-Friendly Than The Panels On Your Roof

Spray-on solar cells take less energy to make and can be put on everything from jeans to cars.

Scientists are one step closer to spray-on solar power. Instead of traditional bulky solar cells encased in glass--which can be awkward to put in places other than a roof, and take a lot of energy to produce--we may someday be able to easily spray paint low-cost, low-energy solar cells on everything from a pair of jeans, to a car, to the side of a skyscraper.

Research on painted solar cells isn't new, but it has been challenging to make these solar cells efficient enough to actually be useful. Now, scientists in a lab at the University of Sheffield have discovered a trick to making them work better: A material called perovskite, which can be almost as efficient as silicon, but cheaper to make and, in theory, more environmentally friendly.

Making silicon--the main component in most solar cells today--takes a huge amount of energy as silica rock is heated up to about 3,000 degrees. Ironically, solar-cell manufacturing is usually powered by coal or other fossil-fuel-powered plants. Perovskite, by contrast, takes little energy to produce, and spraying it on saves even more energy.

It's going to take a little longer in the lab before it's actually ready to use, however. At the moment, the spray-on solar being tested at the University of Sheffield is only about 11% efficient--a huge step up from the 1% efficiency of similar spray-on solar a couple of years ago, but far from perovskite's potential of 19%, or silicon at 25%.

It also doesn't last as long as conventional solar cells, so it's unlikely to start replacing rooftop solar panels anytime soon. But it may start to show up on different types of products where traditional solar panels wouldn't work as well.

"First applications could be in more low-lifetime products in which long-term stability is not required, i.e. on clothing, or for various indoor applications to scavenge energy," says lead researcher David Lidzey. Later, the technology might be used in stable places like the gap between two windows, and eventually, on the facade of buildings.

For now, the researchers are working on making the technology more efficient. Perovskite may keep evolving as well. Today, it's made from a not-so-environmentally-friendly lead chloride, and other researchers are working on finding a better material.

The fact that perovskite is so cheap might mean that it can help bring solar power to people who might not otherwise have been able to afford it. "The technology offers the ultimate potential of very low-cost solar energy, with photovoltaic devices built into many varied environments," Lidzey says. "This will be particularly important in the developing world, where access to low-cost, carbon-free energy will be an important part of making sure that economic and population growth happens in a sustainable fashion."

[Photo: Flickr user Andrew Magill]

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5 Comments

  • Steven James Silva

    New Energy Technologies (symbol NENE) beats the pants off the outfit described with a spray on solar window among other novel solar glass technologies producing electricity in fact far better than conventional bulky solar cells.

    See here: http://www.pennystocksweekly.com/otc_stories_1_20_11_a_look_through_new_energys_solarwindow_coating.html

    "The results that New Energy got from their SolarWindow application were surprisingly good. Engineers were able to demonstrate a cost savings of $40,000 to $70,000 per year for one 40-story building, as opposed to only $20,000 in savings for a rooftop installation on the same building. What is also interesting is that the product has been shown to produce electricity from artificial sources of light better than traditional solar technology. This can provide additional savings in the winter when interior building lights are used more. SolarWindow works both ways and can turn this light back into some energy."