Patriot Solar Group (PSG), a provider of solar tracking and solar tracking equipment, recently developed a new product aimed at companies generating their own power.
The company’s new product is a solar tracker that automatically tilts PV panels to follow the sun wherever it goes. An up-and-coming application of PSG’s solar tracker is used in flat-roofed carports at schools, universities and large businesses. Carports equipped with a solar-panel control system protect vehicles from the elements and collect energy – either to fuel electric cars parked below or to return power to the building’s energy grid.
One controller can drive 500 feet of solar panels versus the previous approach, which required one device for each panel.
According to PSG, solar panels operated by automatic control systems can generate up to 30% more power than static panels.
PSG’s team met with a Rockwell Automation representative who helped them develop an effective control system. Each new PSG tracker comes equipped with the company’s Sun Scout control system. The “brain” of the system is the Allen-Bradley MicroLogix 1400 controller from Rockwell Automation. Instead of relying on the weather, the controller uses software pre-programmed with data from National Renewable Energy Labs. This data automatically provides accurate information on the sun’s exact position – anywhere, any time.
“Using programmable controllers for the solar industry is somewhat of a new concept, but anyone who knows drives will understand the logic behind them,” says Jeff Mathie, president at PSG. “Plus, the MicroLogix controller is a cost-effective, powerful controller that can fi t into a small form factor, so coupling it with the preprogrammed software transforms the system into a ‘smart’ application.”
Allen-Bradley MicroLogix 1400 controller uses software pre-programmed with data from NREL.
To create further efficiencies and protect the system’s hardware, the software also alerts the control system when the sun has set for the day. After 30 minutes of darkness, the PLC tells the system to shift into “stow” or “birdbath” mode, putting the panels in a protective position facing straight up at the sky. That way, they will not be damaged by high winds at night.
Likewise, if the controller detects gusts reaching 35 mph or higher during the day, the system will transition into protective mode. After a minute of winds under 35 mph passes, the Sun Scout system redeploys the trackers to resume their prime, sun-tracking positioning.
The control system resides in a completely sealed plastic box on top of the car-port next to the solar panels. The controllers communicate over an EtherNet/IP network, which provides reliable, high-speed communication.
PSG says the unit arrives on site entirely integrated with preset controls, including latitude and longitude information specific to its location. The end user only needs to enter the date and time of day before the system instantly starts autonomously tracking the sun regardless of external conditions.
NREL data automatically provides accurate information
on exactly where the sun is – anywhere, any time.
“The MicroLogix controllers are powerful little devices,” says Mathie. “By networking the PLCs, we can deploy them for multiple drive systems – much less expensive than our past approach.”
One PLC can drive 500 ft. of panels that can generate 110 kWh of power in perfect sun conditions, says PSG, whereas previous systems required one sun sensor per panel. Furthermore, with minimized equipment wear and tear, the new controller extends product longevity.
PSG has already used the next-generation system to retrofit 18 projects.