6.1 The Dual Angle Solar Harvest (DASH) Method: An Alternative Method for Organizing Large Solar Panel Arrays That Optimizes Both Harvested Solar Energy and Constrained Spaces

Tuesday, 14 January 2020: 10:30 AM
256 (Boston Convention and Exhibition Center)
Jennifer Lynn Kafka, Rutgers Univ., New Brunswick, NJ; and M. Miller

Solar energy has been the fastest growing renewable energy resource in the world for the past three consecutive years. A large part of this growth can be attributed to the steadily decreasing cost of installed solar panels, which is thanks to advancements in technology as well as more and better tax incentives. The direction and tilt angle at which a fixed solar panel is installed largely affects the amount of total possible harvested solar energy. Many studies have focused on calculating a single tilt angle that optimizes a region’s local radiation field, climate, and geography. While these studies have primarily focused on optimizing the amount of solar radiation that can be incident on a solar panel at a particular location, they have not optimized the land cost. In other words, solar panels take up space and space costs money. Large solar panel arrays are often organized into rows of solar panels. These rows must have ample spacing so that adjacent rows aren’t often shadowed by the rows in front of them. It then follows that rows of higher tilted panels must be spaced out further than rows of lower tilted panels in order to minimize the shadow problem. By orienting all solar panels at the same tilt angle, all rows must be spaced the same distance apart, assuming that the solar array is on a flat surface.

This is where the Dual Angle Solar Harvest (DASH) method is born. The DASH method theorizes an alternative solution to organizing a large solar panel array by constructing the array with rows of solar panels at two different tilt angles. While there are some combinations of two angles that can come close to the efficiency of a single tilt angle, no combination can beat the single tilt angle alone. However, a dual-angle array can actually generate more energy in the same footprint as the original array. This is because the best combination of two angles is usually comprised of a lower tilt angle and a similar or slightly higher tilt angle compared to the optimum tilt angle. This results in a dual-angle system that can fit more rows of solar panels into the same footprint as the original single tilt angle system. An added benefit is that the lower tilted panels can actually better harvest the diffuse field of radiation, which can be a significant portion of the total radiation field in partly cloudy and cloudy climates.

While the cost of installed solar panels is decreasing, the cost of land is generally increasing. Thus, it can make more economical sense to spend a little more money up front on extra solar panels as part of a dual angle system that can not only fit into the same footprint as the original single tilt angle solar array, but can also generate more energy per area compared to the original array. The DASH method optimizes both the maximum possible incident solar energy on the pair of angles as well as the lowest number of solar panel rows to accomplish an overall gain in harvested solar energy in the same footprint as the original array, thus reducing costs as much as possible.

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