Solar Panels that Track the Sun

August 18, 2012 by  
Filed under Green Energy News

Photovoltaic arrays and solar water heating systems are already fantastic options for homeowners and businesses looking to reduce energy bills in an environmentally-friendly way. For those who want to maximize energy output, solar trackers may be an ideal add-on to an existing power system.

How It Works
The average solar installation is static, meaning that it will not move (if installed correctly). However, during the course of a day, the sun moves across the sky, meaning immobile panels will not always have the optimal angle for capturing energy.

Solar trackers can make an installation generate even more energy by moving the equipment to follow the sun’s path across the sky. That way, the power system is at the ideal angle to maximizing output, according to Sustainable Plant.

“Photovoltaic trackers are used to minimize the angle of incidence between the incoming light and photovoltaic panel, thereby increasing the amount of energy produced from a fixed amount of installed power-generating capacity,” Mahdi Sebti wrote in an August 13 Sustainable Plant article.

Smaller photovoltaic installations, like the ones a typical homeowner might have, use what is known as a dual-axis tracker. This type of device allows the PV panels to track the sun from all angles. A two-axis tracking device can make a solar panel 30 to 40 percent more efficient at capturing sunlight than a static installation, Sustainable Plant reported.

How A Tracker Finds The Sun
There are two main methods solar trackers use to identify the sun’s location at any given moment. One method leverages a camera in conjunction with global positioning equipment.

The other method involves programming a motor to automatically move solar equipment to where the sun will be at any moment. Using the Solar Position Algorithm developed from the National Renewable Energy Laboratory, the sun’s position can be calculated based on day, time and location of the installation.

A new method developed at the University of Wisconsin could potentially change how solar trackers work. Researchers have devised a system that involves measuring the temperature of liquid. As the liquid warms and cools based on the sun’s location, the equipment uses the temperature differences to roughly calculate the sun’s position.

Comments are closed.