The sun should keep burning for another five billion years or so, and it may take that long to develop a solar-powered phone that customers want.

Many handset makers have tried. Last year, Nokia’s solar-powered prototype packed a bunch of photovoltaic cells onto the back of a handset that ended up only providing enough power to keep the phone on standby.

“What is the job to be done here? Why do you put a solar panel on a handset? Seems like a pretty simple question, right? And the answer seems to be, of course, ultimately to power the cell phone,” said Mike Morgan, senior analyst at ABI Research. “But the amount of help that it’s giving is almost inconsequential.”

Both Samsung and LG have both also taken cracks at practically implementing solar power in mobile devices. The former’s Blue Earth failed to change the world—despite decent reviews--and LG’s Pop suffered a similar fate. Both phones, like Nokia’s, placed the solar panels on the back of the phone, meaning the front functions of the phone were inaccessible during charging. And in all cases, the addition of enough solar panels to create a meaningful power supply meant the device was bulked up way past the standard slim profile seen in so many mobile devices today.

These are problems that could be ultimately solved with Sunpartner’s WYSIPS (pronounced “wee zips”) technology, which the company will be demoing at this year’s Mobile World Congress.

Sunpartner has many different applications in mind for WYSIPS on a larger scale, where the technology could be laid over windows, outdoor displays and woven into fabric. But WYSIPS Crystal is specifically designed to be used with touchscreen devices and hopefully put back some of the power they so rapidly drain from batteries.

WYSIPS Crystal is a 0.5 millimeter-thick layer of photovoltaic cells and a lenticular surface fused together and placed (read this sentence again) over a touchscreen during manufacture. Once installed, WYSIPS can deliver around three milliwatts per square centimeter out in the sun or under artificial light. The company is hoping to double that figure in the next two years but at that current output, it comes out to about 232 milliwatts for an entire 3.5-inch display, such as on the iPhone 3G Sunpartner uses in demos.

Sunpartner marketing director Matthieu DeBroca said, “As long as you expose the device to light, artificial or natural, there will be some energy produced.”

“With one hour exposure, like if you lay your device on your table while you’re working or sipping a beer in your garden, you will get around 10 minutes more speaking time.”

When Sunpartner debuted WYSIPS at CTIA in 2011, WYSIPS had reached 70-percent transparency and supplied around 5.8 milliwatts per square centimeter. As the transparency has increased, the amount of power conversion has decreased, but it still produces a good amount of energy.

“We can’t say, technologically speaking, that we can recharge the whole phone because that would be a lie,” DeBroca said. “But we can give you 20 percent additional time during the day between leaving from and returning to your home.”

That’s the promise that WYSIPS carries with it entering into Barcelona along with the 95-percent transparency is has recently reached, making the layer nearly invisible on top of the display. All this and Sunpartner comes to town with a new trophy to show off having been recently awarded the title of Nobel Sustainability Supported Clean Tech Company 2013. But its real draw has to come from being able to keep the battery alive.

“If this thing was good enough so that solar panel could at least negate the draining effect of leaving a phone on standby, I think that that could be in itself the value here,” Morgan of ABI said.

WYSIPS does approach a sort-of infinite standby capability with the energy it provides. But as an added bonus, the technology can address another typical gripe in regards to touchscreen devices: viewing angle.

On the iPhone 3G Sunpartner uses in its demos, the average 50-degree viewing angle on the device was enlarged to a full 180 degrees by placing the film inside the device. So the film could present a low-cost solution to improving the viewing experience on less expensive devices with lower quality displays that perform poorly when viewed at an angle. And DeBroca said that this effect can be applied in reverse as well to increase privacy, which could be seen as a definite plus depending on the manufacturer.

DeBroca said that the technology Sunpartner is showing off now is ready and that WYSIPS should come to market this year. He has also began a push to raise the technology’s profile in the U.S.

WYSIPS might not take the world by storm as it begins to arrive since the amount of energy it provides is still fairly small and the rapidly evolving technology surrounding touchscreen devices like smartphones and tablets will only continue to demand more power. But by making itself nearly invisible and tucking itself away inside the phone where nobody will notice it, WYSIPS has eliminated bulky awkwardness that plagued so many solar-powered phone designs before.

And with perks like boosting viewing angles added to the equation, it seems like WYSIPS could be a strong value proposition even as it continues to work on providing more power. But even the small amount of juice it gives off now should be welcome considering the dire state most mobile device’s batteries are in by the end of the day.

“Every single milliamp you can add back into the system is a good thing,” Morgan said.