Solar technologies

Article 1: New transparent solar panels could fit invisibly over windows and phone screens.

By Barbara Speed

Much as they’d hate to admit it, most people are far more likely to make eco-friendly life changes if they require the absolute minimum in effort and inconvenience. Yes, we all want a low-carbon future; no, we don’t want a wind farm next door.

Lucky, then, that a new type of solar panel has arrived. It isn’t ugly, inconvenient or loud; in fact, it’s practically invisible. The panel, developed by a team at Michigan University, is transparent, and could be used to fit over windows – or tablets, electronic signs or mobile phones.

This technology is a step forward from similar panels, which are see-through but tinted, and therefore less useful. As Richard R. Lunt, one of the new panel’s creators, puts it: “No one wants to sit behind coloured glass.”

There’s a reason it’s been so difficult to develop transparent solar panels. Completely transparent materials let nearly 100 per cent of light through (that’s how you can see what’s on the other side). But solar panels function by siphoning off some of the light as energy: if they let all the light through, how can they collect any energy?

The breakthrough made by the Michigan State researchers was to find a way of collecting invisible wavelengths. Their panels are embedded with salts that absorb infrared and UV wavelengths; something called a “transparent luminescent solar concentrator” then converts these into wavelengths that traditional solar panels can absorb. These are then channelled to the edges of the panel, where thin black strips of the cells used by traditional solar panels convert them into electricity. The result? A panel that lets all visible light through, but still collects solar energy.  

This faintly confusing diagram from the panel’s creators shows the process. The squiggly purple line represents non-visible waves, obviously:

The technology is still in its early stages: the prototype is only 1 per cent efficient, which means that the panels can only turn 1 per cent of the sunlight that hits them into usable energy. The scientists hope to increase this to 5 per cent, but even this is far lower than most commercial panels: the most efficient panel created so far had an efficiency of 47 per cent; even other semi-transparent solar panels manage 7 per cent.

The unobtrusiveness of the transparent panel might outweigh these drawbacks. It’s unclear how expensive they would be, but if they use less energy to produce than traditional panels, the low efficiency might not matter that much.

There’s another advantage. Solar panel maintenance – which means clearing dust and dirt from the surface so light can reach it – is something users would do automatically, to enable their existing routines. Like, say, texting. Or spying on their neighbours.

Article 2: Low-cost solar

• by Mit TR Editor

Solar cells can produce 10 times more electricity per gram of silicon thanks to this system, which concentrates sunlight on the cells with the help of parabolic troughs and a tracking system that keeps them pointed at the sun. Concentrated sunlight ordinarily causes solar cells to overheat, impairing their performance, but this system uses heat sinks and convection to prevent that problem. The reflective troughs, a type already used in solar thermal plants that concentrate sunlight to make steam and drive turbines, can be made in high volume at low prices.

Resume:

The question of the use of natural resources is very important nowadays. Article One speaks about researchers who are trying to find alternatives to non-renewable resources like oil. The goal is to find a renewable energy that does not cost too expensive and that is easily usable. Researchers in Michigan have developed the idea of solar panels. They could be utilize on our windows, our mobile phones. This can be made possible thanks to the transparent material they developed. Although this technology is still in its infancy, the idea deserves further study.

Obviously the technology of solar panels exist already but its biggest problem is the cost. This is why people from MIT tried to develop a system that can reduce this cost. The advantage of their solar panels is that they do not overheat due to the temperature as is the case with only the traditional solar panels. Their technology allows them to make more efficient panels and produce more electricity

So even if oil reserves are not empty yet, we must think the energies of tomorrow and that is why researchers are trying to find new ideas for the needs of tomorrow.