The QBotix Tracking System uses a monorail system of robots to tilt solar panels toward the sun as it moves throughout the day, replacing tracking systems that are complex and expensive to install and maintain. (Source: QBotix)
Once the "solbot" (Sol, as in Sun) breaks, the whole system is useless. They claim reliable, but put some bugs or animals in its way, on the track, and then what?
I like how they combated the old concept of having each panel move with its own motor. Each panel is then positioned optimally. This appears to be cheaper. I wonder how a typical day finds the Solbot. Is it able to power itself? Without the bot, how much energy is saved? And how would the same array fair with just moving all panels at the same time like puppets compare?
Under present designs, there are already low function robots on every panel, they are considerably >underutilized< and >massively< redundant! It makes sense to me to consider replacing that capital (expensive, life-limited wear items) with a concentration of robustness and intelligence in a few mobile units.
Suppose you have a robot built to wash the panels and perform routine maintenance and repairs, including damaged panel replacement. Such a robot is practical and necessary. It would be relatively trivial for it to also perform the function of the QBotix monorail. It would not necessarily require rails; although rails increase efficient, long balanced arms and/or gantries on a wheeled maintenance vehicle might have similar returns. The panels could have passive breakovers that let the panels lay over in severe wind gusts and be reset by the robots.
I think there is no reason to suppose that the fault tolerance of the system must be realized in a single robot, nor even that multiple-redundant robots are needed to achieve some consensus as to which ones are "sane". Any supervisory functions that manage the solar farm would also monitor the correctness of each of the tactically redundant robots.
As to the question of the relative production volume of the robot, I suggest that mass-produced robotic fruit and vegetable pickers under development (e.g., Vision Robotics) could be downrated and repurposed to the relatively simple tasks of solar panel washing and tilting.
Ttemple, I won't for rotating the entire farm by a single motor. Clubbing some panels in single frame and each frame can be rotating using a powerful motor instead of independent motor for each panel. This may be a cost effective solution when compare with many independent motors.
Scale describes the problem well. Go big enough and mountains look like check marks on a site plan.
I would be more concerned about how well the mechanical linkage on the Qbot method holds up to repeated interface cycles. It could fail to hold position after aiming and wind blows against the panel, putting torque on whatever it is that's supposed to keep it from moving while the Qbot adjusts all the other panels.
Don't worry, I wasn't really thinking about digging a ditch around my property...
Your points are good if random, odd, small locations are used.
If your plans were to invest considerable moneys then site location and site prep are paramount. Dips, valleys, trees and buildings can all be corrected. This brings down the complexity of control and ultimately cost of operation.
Two axis cotrol is assumed with two controlling motor inputs. I don't see a lot of success in future use of the super flexable robot setup unless PV panels get a whole lot more efficient than present. Return on investment is too slow.
I am sure PV efficiency will get there sooner than most expect but it may be 5 to 10 years.
I tracked satellites using very large antennas for 20 + years. I do understand what it takes to track and follow moving targets accurately. Those same antennas are still in operation nearly 50 years later but now with electric drive rather than the massive hydraulic drive system they started out with.
Your over the top suggestion (I hope) of propellers for guidance reminded me of a Jules Verne scheme. :)
The robot looks very interesting but time will tell if it is practical.
I can see them as a first step in an even better future design.
Not all solar panels have the same useable angle that they can be off by. The cheaper solution is to pick a wide angle panel and skip the tracking gear. But a panel with a narrower alignment could easily make more power for the same amount of light.
There's a company I saw years ago that made a tracking system that used a pair of reservoirs, one each mounted at opposite sides of a panel. Both cannisters were connected with a single tube. The system was filled with a fluid that turned to a vapor at very low temperature. Some sheet metal shielded each can so that when the panel was tipped to the east, sunlight would be able to warm that side but not the western cannister. The fluid would expand and travel out of that side to the other where it recondensed. At a certain point, the entire deal gets weighted far enough to tip over so it's facing west. Using a solar panel that makes the most of only half of the sky finished the design. In the morning when the sun starts to rise, the western side gets warmed up, the fluid travels back to the eastern side and the panel tips back to face east.
Well, for some reason S. Jersey has a lot of solar farms going up. So far as I can tell they are all of the fixed panel type. I often imagine that they could improve output by going with tracking, but perhaps this is a case where simplicity has the advantage of being easiest to implement and maintain.
rspake: I believe the requirement to use a mobile robot is also based on the fact that the monorail structure can be placed in any location, routed between trees & buildings or even across rooftops. It's a very flexible design for being capable of placement in any possible situation, even one of those badly planned government jobbies you mentioned.
Year-round aiming requires more than just choosing what azimuth is needed every few minutes. The sun follows a path that changes in height every day. It won't matter if a Qbot on a monorail is used or a structure like what you described, the installation itself could be less than perfectly flat & level. So each panel needs a slightly different elevation adjustment as well as tracking the azimuth.
A one motor single axis array will need a very well trussed structure in order to move as a unit without flexing noticably, and will also need a very large circular space cleared of all objects, which means it wont work in a suburban environment or any kind of existing building sites such as in industrial parks or around a hospital for example. No matter how you gear down, you'll still be moving a lot more weight with that one single motor so it'll still need to be a lot more horsepower and consume a lot more power. Plus cost more to purchase.
And did you consider placing panels across the entire area your circular structure will be operating inside of? Maybe you could try floating the thing on pontoons in a circular ditch just to take the weight off of the central spans. And then a much simpler approach is to have an anchor pin to keep the structure from drifting into the sides of the ditch and use propellers mounted all around the outer perimeter to make it rotate.