Here’s an image from a journey to the future: huge solar power stations with millions of mirrors. In those stations, thousands of robots are on the go, polishing, fixing and turning the mirrors to the sun.
Yesterday in its infancy, today solar energy is entering its early childhood years. It is still hardly significant worldwide, yet its popularity grows every year. It was this August when the world’s biggest power station of this type was opened in the Mojave Desert on the border between California and Nevada. It is called Ivanpah Solar Power and it consists of 170,000 mirrors reflecting the sunlight and focusing it on top of three 150 m tall towers, where the water heats to create high-temperature steam, which then turns turbines. The plant’s capacity of 377 MW is enough to supply power for a city with a population of half a million.
Modern as it is, Ivanpah Solar Power remains a fairly traditional power station. Why? Because you won’t find there a fellow named Wall-E and his equally hard-working mates. Who are they and what do they do? It’s time for a presentation. Wall-E belongs to the first generation of robots which are supposed to cut down the cost of solar energy and thus to speed up its path to adulthood. Currently the main task of this silver microwave-sized machine is to keep the mirrors, called heliostats, turned towards the sun. Exact control over these mirrors helps to generate much more solar energy and, consequently, reduce the costs of electricity generation.
The latter statement is not a big discovery. For a couple of years various attempts have been made to turn heliostats so that they would be adjusted more or less perpendicularly to the sun angle. Some more simple systems rotate the giant mirrors only along the horizontal axis, whereas those more complex move them vertically as well. Nevertheless, both are hideously expensive, as each heliostat needs the installation of an engine which operates a complex system of gears and levers. Not only does it cost a fortune, but it often breaks down as well. Of course, as cost-cutting exercise, one may settle for a cheaper, “fixed-tilt” power station with mirrors positioned permanently at the cost of reducing the capacity. Either way, it’s bad.
That’s where our hero comes in! Invented by a group of robot enthusiasts from Silicon Valley, Solbot goes from one heliostat to another, rotating them towards the sun. As it turns out, you don’t need thousands of small engines and steel arms. It took three years to develop the robot. The work was done by young researchers from two famous Californian universities: the California Institute of Technology (Caltech) and Stanford University. Then, those of them who had some business experience (i.e. they went under a couple of times but they never gave up) looked for sponsors and found them, of course.
Solbot is now being tested at five sites in the world – in the U.S. and Japan. Moving along special monorail, it adjusts solar mirrors by 10 degrees every 40 minutes. Wall-E needs just a few seconds to tilt one panel, less than a second to make it to the next mirror. It is powered up by a battery, which needs charging once in a while.
Soon, the robot will be joined by SPOT, also a rail-based robot, only responsible for keeping heliostats clean and controlled by a laptop or smartphone. SPOT will automatically clean the mirror if it is dirty. Both robots were equipped with a GPS receiver, a set of sensors and wireless module to communicate with the main office. This duet will be shortly joined by even more intelligent devices doing minor repairs. They will not need any commands, as they will automatically diagnose and then fix the failure (or they will report it if the breakdown turns out to be more serious).
According to some experts, the robots will reduce the cost of electricity generation in big solar power stations by 20% over the next decade. It is a matter of time when machines able to build such plants will be developed , which will also bring the costs down. Yet we’ll have to wait for it two or three decades, although first prototypes of such giant robots are already available. And that makes me wonder when we will come to see a robot that will cut off electricity in our house when it figures out that we’re wasting it.