Google+

BBC Future

Matter of Life & Tech

Nomadd: Cleaning solar power's dirty side

About the author

Jonathan Kalan is an independent journalist and photographer specializing in social innovations in emerging markets. Based in Nairobi, Kenya, he frequently reports from around the region, specialising in the spaces where technological innovation, social justice and media converge. You can find him on Twitter at @kalanthinks

Testing Nomadd (Copyright: Kaust)

(Copyright: Kaust)

The simple device that could finally allow solar panels to be located where they would get the most sun. A tech-fix to a grubby problem

Putting solar panels in the Saudi Arabian desert sounds like an obvious thing to do. There’s cheap real estate, ample sunshine and the possibility of one of the biggest oil-producing countries transforming itself into one of the biggest producers of solar-energy.

It is something that cannot happen quickly enough. Around a third of the oil pumped in Saudi is used to generate electricity for the country, while demand for power is growing at around 8% a year, the fastest in the region. If these rates continue, some estimates suggest the oil capital of the world may one day become a net importer of oil to power itself. Yes, you read that right- the country with one of the world’s largest oil reserves could actually have to import oil.

As a result, the country plans to invest a staggering $109bn over the next 20 years into solar, with the intention of generating more than 30% of their electricity from the sun - up from practically zero today. It is all part of the government’s plan to break the country’s oil dependency and give it a long term future after the oil reserves eventually run dry.

But if all of this sounds too good to be true, you’d be right. Saudi Arabia’s plans have a dirty secret.   

Lego build

In just one hour, a desert sandstorm can plaster even the toughest solar panels with a thick layer of residue, reducing their efficiency by upwards of 70-80%.  If the panels aren’t cleaned almost daily, they become virtually useless.

Most solar installations around the world, large or small, use automated water cleaning devices, or manual labor with hoses to wash them down. But Saudi Arabia is in one of the driest regions on earth. Around 90% of its water supply comes from desalination – converting saltwater to freshwater. It is a very expensive and energy intensive process.  Using this precious resource to clean vast arrays of solar panels in the desert would be a waste of the energy they produce, as well as making the economic model more difficult to justify.

So, while there is tremendous potential for harnessing solar energy from desert environments, it has been relatively impractical on a large scale. But that may soon change.

Enter Nomadd, or “no-water mechanical automated dusting device”, a waterless solar panel cleaning device designed specifically for use in harsh desert environments. Once a day, Nomadd pushes dust and dirt away from panel surfaces with an automated “dry sweep.” It can even clean the thick dust that sticks after a rain shower or sand storm in humid conditions.

“Basically it can clean solar panels without water. It’s a brand new solution to a brand new problem,” says German-Australian engineer Georg Eitelhuber, a physics teacher at the King Abdullah University of Science and Technology (Kaust) in Saudi Arabia, who invented the ingenious device.

“This whole project started with Lego and toilet rolls,” Eitelhuber says of his early days prototyping the Nomadd in after-school experiments. “And now the idea’s gone up to some pretty high levels in the Saudi government. It’s kind of crazy”

Nomadd is as simple, rugged and low-maintenance as possible, with just four major moving parts. Eitelhuber is reluctant to reveal too many details, as he has various patents pending. However, he says the device is designed to run along a bank of solar panels, sweeping away the dust. It is powered by lithium-ion batteries, charged by the array and is able to maneuver over gaps and obstacles between the panels. It can be used as often as desired- either automatically on a schedule, or instantly with the touch of a button in a remote control station.

“This allows the entire array of banks to be cleaned in a short time, which is essential after a sandstorm” says Eitelhuber.

In February, the device won $200,000 from Kaust’s Seed Fund, which offers finance and support to students, faculty and staff who want to turn their discoveries into commercial ventures. With the money, Eitelhuber is now testing a full-scale Nomadd designed for larger solar arrays- like the kind planned for Saudi Arabia.

Nomadd’s timing couldn’t be better, says Ibrahim Faza, the project coordinator of Kaust’s Seed Fund. “They are providing a solution at the right time,” he says. “Nomadd is very early in the market, because the market is now being planned.”

It is a claim supported by Christopher Burghardt of First Solar, one of the world’s leading solar solution providers. He says Saudi Arabia’s bold solar vision is likely to set off a wave of solar development in the region.

“The Middle East will be one of the major global markets for [photovoltaic] solar in the coming decades,” he says. “In particular, Saudi Arabia.”

Within the next year, large-scale solar arrays are expected to begin sprouting up in the desert, and Eitelhuber hopes Nomadd will be ready to help kick-start the efforts.  

“We think we have the best solution by a long shot to cleaning solar panels in the desert,” Eitelhubert claims.

And Saudi Arabia is the just beginning, he says. If it can work there, it can work anywhere.

“It’s desert-proof,” says Eitelhuber. “Anywhere that has tough conditions that need tough solutions, we’re looking there.”

If you would like to comment on this article or anything else you have seen on Future, head over to our Facebook page or message us on Twitter.