Robot with brush, water, wiper tackles solar panel cleaning

Credit: Sinfonia Technology (previously known as Shinko Electric Company)

At large-scale solar plants, keeping the surfaces of solar panels free from dust, sand and bird droppings is not just a matter of finicky housekeeping.

It can be a matter of plant profitability. Dirty panels lower power generation efficiencies.

Bird droppings on panels, for example, block the sunlight.

A Tokyo-based company has a solution. Sinfonia Technology announced late last month that it has developed a robot with camera and sensors that can move autonomously and clean solar panels at large-scale solar power plants.

Sinfonia's robot has a distinction in being "autonomous" in that, rather than tethered to rails, the robot is able to move from panel to panel, to tackle the panels' dirt and debris.

The robot is equipped with scrub brush, wiper and detergent; and also sprinkles water stored in its tank. The robot can work in the dark; it has LEDs, having wavelengths in the infrared range.

Aside from autonomy, another key distinction is that Sinfonia's robot can handle the fact that not all solar panels are alike; the robot is designed to tackle panels that tilt in different ways.

To clean tilted solar panels on a mounting system, the robot can move on a planes tilted at 5-30°. If there is a gap between panels, the robot can go over a gap of 50cm or less and can deal with a height difference of 30cm or less.

The robot is powered by a battery and is capable of wireless data transmission. A tablet can be used to check the robot's status—to check if, for example, it has enough water or to check the battery charge remaining.

Sinfonia Technology, in promoting the benefits of its panel-cleaning robots, also noted cost advantages over using manpower for cleaning panels.

Generally, experts say that, for large-scale solar panel installations, attention to keeping the panels clean makes sense.

Earlier this year, however, a study out of the Jacobs School of Engineering at University of California San Diego, in quantifying losses of electricity output due to dirty solar panels, found panels that hadn't been cleaned, or rained on, for 145 days during a summer drought in California lost on average a little less than 0.05 percent of their overall efficiency per day.

The overall conclusion was, that cleaning the panels often was not worth the cost, according to the study's engineers.

They cautioned, though, that their study focused on smaller systems and that, for very large installations, economies of scale may mean that washing panels was worth it.

Sharp, meanwhile, is another Japan-based company showing interest in devising automatic ways to clean solar panels.

SUGAR Volt: Boeing's Hybrid Electric Aircraft - YouTube

NASA asked a Boeing-led team to explore the possibilities of a hybrid electric aircraft. Marty Bradley, Boeing Research and Technology, explains how the SUGAR Volt concept is defining the future of flight.

Antonov's 3-speed transmission for electric vehicles boosts efficiency by 15 percent

Electric vehicles have been a reality for more than 100 years, but it's only in the last decade or so that the world has truly woken up to their potential as a viable, cleaner urban transport alternative to their combustion engined cousins.

During this EV renaissance much of the focus has been on developing improved power sources like batteries and fuel cells in order to deliver the range and performance consumers have become accustomed to during the age of oil.

Transmissions on the other hand, despite being so important in the ICE space, hardly rate a mention because the wide torque curve of electric motors makes them largely irrelevant. It could be time to rethink that approach according to U.K. based engineering firm Antonov.

The company has produced a 3-speed transmission designed specifically for electric vehicles that promises to bring significant efficiency gains and a better driver experience.

The company's Business Development Manager Dave Paul outlined these benefits in a presentation at the IDTechEX Electric vehicles conference this week in Stuttgart.

Standby: Electric Fish Turn Down Charge for Energy Efficiency

Fish that use electric fields to sense their environments dim their signals to save energy during the day when they are resting.

Sternopygus macrurus, a South American river fish, is a natural practitioner of energy efficiency. It can reshape the charged-molecule channels in its electricity-producing cells to tone down its electrical signature within a matter of minutes.

“This is a really expensive signal to produce. The fish is using up a lot of its energy budget,” said neurobiologist Michael Markham at the University of Texas at Austin, lead author of a paper in PLoS Biology on the fish. “These animals are saving energy by reducing the strength of the signal when they are not active.”

Thousands of fish and other oceanic creatures use electrical fields to help them perceive their environments. The most famous is the electric eel, which a colleague of Markham’s termed “a frog with a cattle prod attached,” but most animals use the electrical signals in more subtle ways.

The fish’s standard electrical signal runs at 100 hertz; if you turn the electrical signal into sound, it sounds like a hum high whine. In laboratory experiments, the fish can detect tiny bugs half a centimeter wide and easily navigate obstacles by detecting the changes the objects cause in the electrical field.