Sun-Tracking RobotTom Lombardo
posted on March 27, 2013 |
Isaac Asimov never wrote a novel about a robot that optimizes the production of solar energy, but if he were alive today, I think he’d be quite impressed by the QBotix Tracking System (QTS), an innovative method of keeping an array of solar panels pointed directly at the sun throughout the day.
A fixed-mount photovoltaic (PV) panel only faces the sun at solar noon. For the rest of the day the sunlight hits the panel at an angle, which decreases the amount of light that strikes the panel, and in turn, decreases the electricity generated. Many solar panel mounts include one or two motors to track the sun throughout the day and the year. Dual-axis tracking can increase the daily output of a solar panel by 25% or more compared to a fixed mounted panel, depending on local conditions. For utility-scale PV farms, adding motors to each mount is costly. Also, each motor becomes a potential point of failure. Coupled with the extra maintenance required, it may not be cost-effective to include tracking motors.
QBotix has the solution: a robot that moves around the entire solar farm and adjusts the position of each panel, one at a time. One robot means one part to maintain and one potential point of failure. Cost is decreased while reliability improves, and the panels are always facing the optimal position relative to the sun.
The above picture shows the QTS track weaving its way through the PV farm. The track includes a cable tray to house electrical wiring. The robot makes a pass across the entire array, adjusts each panel as needed, goes back to its starting point, and repeats the process, constantly making small adjustments throughout the day. It returns to a charging station when it needs to recharge its batteries. The QBotix includes software that monitors system performance and runs self-diagnostics. It also has wireless communication ability. There are two robots per track – one is a backup in case the primary unit fails.
Here’s the QTS in action. (Don't adjust your speakers - there's no sound.)
One QTS can manage an array of up to 300 kW. The system is modular so it can be scaled up. Designed to work in harsh environments like deserts, the QBotix robot is waterproof and dustproof.
QBotix doesn’t say whether their robot obeys Asimov’s Three Laws of Robotics, but I’m pretty sure it wouldn’t harm a human being (First Law).