Trackers
Impact
An increase of 100% or more cumulative energy per unit area above the performance of today's SiPV flat panel arrays. The better the HCPV cell and loss management the further beyond 100% efficiency improvement becomes possible. The use of electronic trackers (eTrackers) will allow XE to obtain close to 100% land area coverage while using the best HCPV solar cells currently available. The XE products would have the best feature of unconcentrated PV panels: 100% area fill; and the best feature of concentrated solar panels: high efficiency PV cells. All while eliminating the large-scale mechanical trackers currently utilized.
FIG 3.5 Arrays, Efficiency and Cumulative Energy. (A) Sparse solar tracking arrays for concentrating thermal, concentrating PV, and SiPV all currently have the same poor area utilization. (B) Area Efficiency of three different solar receiver configurations. (C) Cumulative Energy Density of three different solar receiver configurations. The three cases are: Case-1 (Dashed Blue) is a single 1 m^2 solar panel having 20% conversion efficiency on a large mechanical 2-Degree of Freedom (DOF) tracker providing 100% area efficiency because there is no unused space around the tracker or neighboring trackers that shadow it. Case-2 (Red) is the same solar panel as in Case-1 but now surrounded by a very typical array with a 50% packing density. This corresponds to the sparse array of image (A). Case-3 (Green) is an XE eTracker utilizing solar panels with an overall conversion efficiency of 20% (35% HCPV cell and a panel efficiency of 25%). The SunStalker electronics tracker has an embedding dielectric of n1 = 1.5 and a 100% packing density. The image shows how the losses due to using a sparse array are recaptured using eTracking---single panel (blue) to array of spaced trackers (red) back up to fully recovered area (green) plots. Finally, in case-4 (Black) we have the same conditions as the green plot but now with a 40% panel conversion efficiency achieved in by a combination of XE low loss concentrator lenses and future advances in the HCPV solar cells. Plots for sunny Barstow CA.