Solar panel cleaning method goes 
 intergalactic – as NASA investigates 
 airflow cleaning of its Mars rovers 

The idea of life on Mars has mesmerized mankind for centuries. Much remains to be discovered, but it’s an established fact that the atmosphere on Mars gradually coats solar panels in dust and reduces efficiency, just as happens here on earth.

NASA has two roving vehicles – ‘Opportunity’ and ‘Spirit’ – that have been exploring sand dunes and sedimentary rock on Mars since 2004. Though originally designed to fulfill a 90-day mission, the solar powered vehicles have beaten all expectations as to the duration of their working life – Spirit eventually stopped working in 2010 when its solar panels became covered in dust, and Opportunity is still ‘alive’ today.

The vehicle’s future is uncertain though. The same winds that have blown away dust from the solar panels could yet cover them again, and right now Mars is experiencing unprecedented dust storms.

Photograph of Mars without and with the sandstorm. (photo: NASA)

Even without epic Martian dust storms, a previous 90-day mission by the ‘Sojourner’ rover saw its power output reduced by 23% by the mission’s end. Similarly, accumulating dust here on earth reduces solar panel energy production – after one month by up to a third, even in arid regions like the Middle East, unless they are expensively maintained.

A Mars rover can be angled to ‘catch’ surface winds and blow accumulated dust away, but earth’s solar farm panels are fixed in place. This is where London based startup ‘Aerial Power’ comes in, which has developed panel cleaning by using specially adapted ‘cleaning’ drones.

Their highly accurate self-flying drones create downdraft over the solar panels – row by row – the downward airflow from which is enough to blow away the dust.

The Startup will target sun-rich arid regions of the world. Solar power production is booming in these areas, but the cleaning costs are high and logistically challenging. So the startup has been conducting tests in India’s Rajasthan desert.

Monitoring of solar panels in the Rajasthan desert (photo: Aerial Power Ltd)

“Our aim is to reduce operation and maintenance costs for solar panels, and therefore raise panel profitability to allow for solar farms to be established in more marginal areas. With our cleaning drones we anticipate being able to significantly reduce the frequency of any manual wet cleans” the inventor and founder Ridha Azaiz explains.

The US Patent and Trademark Office – finding the cleaning method novel – recently granted patent No. US 10,046,857. This is in addition to the previous granting of European (EP 3077882) and Australian (AU 2015285989) patents. (photo: NASA)