How to Leverage Sunlight Hours and Sun Angle to Boost Solar Electric Production

A track rack greatly increases an array's electrical output.

Solar electric production, which is electrical current resulting from the sun's rays striking the surface of solar panels, can be an efficient source of electricity for your home. Errors in site selection however, are costly. You can increase the amount of electricity that your solar panels produce by positioning them to make strong use of sunlight hours and by adjusting the array to the angle of the sun.

Instructions

1. Observe the effects of the sun's rays, as the sun moves across the sky. Notice where shadows fall. Mark the locations that get the most sun.

2. Eliminate locations that often are clouded by dust, smoke or other pollutants.

3. Narrow down the remaining sites for your solar array by determining which sites allow the array to face south.

4. Determine whether the roof of your house or garage has a south-facing side with enough angle and lack of shadow to install a solar array that will catch full sun at least four hours a day, preferably during late morning and early afternoon hours.

5. Consider potential sites to install a track rack, which is a solar panel rack that follows the sun's path. You need a location where you can set in concrete a strong vertical pipe to hold the rack. Determine the height at which the rack needs to be mounted to the post to allow the lowest part of the rack to clear every obstacle it might encounter in its daily movement pattern.

6. Check which direction the wind normally blows by watching a wind sock or weather vane. Contact the weather bureau to review wind speed data. Eliminate from consideration for track rack installation any site that suffers from high winds or strong crosswinds.

7. If winds are low and you have a suitable site, choose a track rack system that allows you to adjust the angle of the rack to seasonal changes in the arc of the sun.

Tips & Warnings

• Passive solar track rack systems that automatically follow the sun require no motor or power to operate. These systems can increase total electrical output by more than 25 percent.

• Single-axis track racks move with the sun throughout the day but cannot be adjusted to compensate for seasonal differences in the sun's arc as it travels across the sky.

• Dual-axis track racks can be manually adjusted to the seasonal variations in the sun's path.

• Snow is more easily removed from dual-axis track racks that have been adjusted for the sun's winter path, because the adjustment steepens the rack's angle.

• Check local and state regulations before installing a solar system.

References

• Solar Energy Industries Association: Photovoltaic Solar Technology -- Creating Electricity from Sunlight
• American West Windmill & Solar: Universal Track Rack
• American West Windmill & Solar: Passive Tracking Arrays
• United States Department of Energy: Energy Savers -- Siting Your Small Solar Electric System

Resources

• United States Department of Energy; National Renewable Energy Laboratory; Solar Maps
• United States Department of Energy: Energy Savers -- Solar Radiation Basics