Robot ‘maid’ keeps solar panels clean
DUBAI // Despite year-round sunlight, plans to make solar power a primary energy source in the UAE are hindered by the all-pervasive dust in the atmosphere whipped up from the desert.
A layer of sand renders solar panels useless, regardless of how bright, and how long, the sun shines each day. But one company could have the solution to the Emirate’s green energy problems in the form of a specially designed cleaning robot.
Nomadd has designed a durable, waterless cleaning robot that “crawls” from one solar panel to another, saving thousands of man hours and countless more litres of water.
Already the firm, which is based in Saudi Arabia, is in talks with several upcoming projects in the region, including Dubai.
Georg Eitelhuber, acting chief executive, was a teacher at King Abdullah University of Science and Technology (Kaust), when he saw for himself what happened to solar panels when they were caught in a dust storm.
“Within a few hours they were filthy,” he said. “I realised that if there was to be a growth in solar in the Middle East, this would have to be one of the key problems that would be solved.”
Nomadd was started three years ago, with start-up costs of less than US$1 million (Dh3.67m) and seed money provided by Kaust. The first working model of the robot was built out of Lego.
The commercial launch of the Nomadd robot comes at a time when the solar industry in the region is beginning to boom.
According to the Middle East Solar Industry Association, by 2020 there could be $50 billion worth of investment in new solar parks.
Last year Abu Dhabi opened Shams 1, a 100-megawatt solar park that generates enough energy to power 20,000 homes. Dubai, too, opened the first phase of a 13-megawatt solar park, that once completed will generate one gigawatt of power.
The biggest investments, however, are in Saudi Arabia, which aims to build 41 gigawatts worth of solar parks by 2020 – the equivalent of more than 20,000 football fields.
Mr Eitelhuber said cleaning a facility of that size would be much more cost effective with robots rather than by employing “thousands of men with squeegees”.
“The labour force required to clean something like that is just astronomical,” he said. “Plus you’d have to install a whole bunch of new desalination plants, using oil-based electricity, to make the water to clean these arrays. It’s completely impossible.”
He said factoring in cleaning costs for solar parks was often overlooked in the rush to build greater and more expensive developments.
“If a dust storm hits you can lose 50 per cent of the performance of the array in just two hours,” he said. “And that will stay at 50 per cent until you clean it. If you can’t clean 10,000 football fields of solar cells in a day, you lose a huge amount of output, which drastically affects your end-of-year bottom-line profit.
“Add to that the uncertainty of labour costs over the next 20 years, in addition to water costs over 20 years. No one has a clue where those costs are going to go. Our business case is that we’ll remove all that uncertainty.”
Mr Eitelhuber said the robots would cost about $100,000 per megawatt generated. They would be able to pay for themselves in three years.
A single robot can crawl over a 400-metre row of conjoined solar panels, completing a wash of that size in about 30 minutes.
Of all the challenges Mr Eitelhuber had to overcome, designing a robot that could withstand the harsh desert environment was the most difficult. He quickly found that similar devices used in the US and Europe just would not cut it.
The finished design looks like a big, unlovely block. But that was the intention, Mr Eitelhuber said.
“What it boils down to is a case of simplicity being equated with beauty,” he said. “The fewer moving parts, the less complexity you can engineer into it, the more reliable it will be.
“The more things you’ve got, the more things that can fail. There’re no exposed parts because the desert will just eat it alive.”
Published: July 6, 2014 04:00 AM