Friday, July 10, 2015

Looking on the sunny side - solar news

I recently came across a bunch of interesting articles on solar panel applications that I wanted to share.
A Dutch entry in the annual World Solar Challenge in Australia took my fancy  It may look wacky and science fiction-ey, but it is at least a more practical machine than most of the entrants into the race, which tend to be low-slung, ultra-streamlined, single occupant affairs, totally impractical for day today use.
The University of Eindhoven's entry, however, fits four passengers, and even has a trunk. It has a respectable top speed of 125 km/h, and can run for over 1,000 km on a fully-charged battery pack. What's more, the car is "energy positive", meaning that it generates more power than it uses, and can upload its excess energy into the grid. Pretty neat!
Also in the Netherlands, in the small town of Krommenie just outside Amsterdam, a bike path made of glass-coated solar panels is producing even more electricity than initially anticipated. In its first six months, the 70 metre bike path has generated about 3,000 kWh, enough to power a small household for a year.
The bike path is made of many small solar panels sandwiched between glass, silicone rubber and concrete (with a laminated coating to provide traction), and is strong enough to support 12-ton trucks without damage, and to last for a estimated 20 years. Each individual panel is connected separately to the grid (or directly to street lighting) in order to prevent unnecessary outages, and the panels around the faulty one are able to pinpoint the problem for quick repair.
In theory, the technology could be extended to regular roads. A California start-up called Solar Roadways wants to see just that happen in the USA, claiming that, if all of America's roads were paved with solar panels, it would produce more energy than the country consumes. Plus, the panels' internal heat prevents ice and snow build-up, and built-in LED lights can even be used to show traffic messages. Is the future really here?
Next, an American start-up company called Ubiquitous Energy has plans to bring to market a technology for producing completely transparent solar panels that was first demonstrated experimentally about a year ago.
Previous "transparent" solar panels have only been partially transparent, and also tended to cast a rather strange colourful shadow. By shrinking the components and changing the way the cells absorb light, though, this new design is transparent and unobtrusive enough to be used in everyday windows. Effectively, the cell selectively harvests that part of the solar spectrum that we humans cannot see with our eyes, while letting regular visible light pass through.
Although currently still quite inefficient in terms of energy produced per square metre, it is hoped that efficiency should increase with commercial production, and also that it will be possible to produce cost-efficient window panels all the way from large industrial applications right down to small consumer models, potentially allowing huge areas to be brought into action. Various spin-off ideas are also being investigated.
And finally, the Netherlands again: decorative, multi-coloured solar panels to be used in practical applications like highway sound barriers, bus stops, even park benches. "Luminescent solar collectors" or LSCs are a cheap type of solar panel that allows for bright colours to be used, and a professor at Eindhoven University has begun a test installation of the collectors as noise-cancelling barriers on the main A2 highway near Den Bosch.
The panels are substantially cheaper than standard silicon-based solar panels, and arguably more attractive. They are essentially sheets of plastic that, depending on the particular dye used, capture a certain wavelength of sunlight, which is then funnelled toward solar cells on the panel’s edges. They are less efficient than traditional solar panels (by about a fact of 2), but they may have wider applications, and the professor envisages their use on bus stops, park benches, outdoor concert stages, and potentially many other sites. Why not?

No comments: