Land constraint makes solar trackers less effective for photovoltaic power generation

<p>Unprecedented photovoltaic (PV) expansion makes land used for solar farms more limited and costly. Packing factors (ground cover ratio) of PV modules may become a key constraint for solar potential assessment, especially for solar trackers that require more land areas for deployment. This constraint is often neglected previously. This study re-assesses the global electricity generation potential of different solar trackers considering packing factor to judge their suitability. A physical model chain was used to convert irradiance to power. Generally, solar trackers help to utilize more radiation, thus increasing global average capacity factor by 8.1 % - 21.5 %, depending on solar tracker type. However, using solar trackers causes smaller packing factor and thus reduces installation density, consequently reducing global total electricity potential by 2.6 – 24.7 %, compared to fixed mounts. This tradeoff is spatially variable, and horizontal single-axis tracker (NST) and dual-axis tracker (DAT) can increase electricity by 5%-10% at mid- and low-latitudes, respectively. To maximize electricity potential, fixed mounts dominate most of the world, and DAT and NST perform better near the equator and at mid-latitudes, respectively. With the optimal solar module deployment, 107 countries can meet electricity demands by developing less than 5 % of their potential, while 17 countries cannot do it even if more than 50 % of their potential are developed, and need other measures like distributed PV to bridge the electricity gap. This study contributes greatly to clarifying the global suitability of solar trackers in land-constraint situations and guiding national and international PV development.</p>