Inter-row spacing calculation in photovoltaic fields - A new approach

The inter-row spacing in photovoltaic (PV) systems is an important design parameter affecting the inter-row shading and the diffuse radiation masking losses and hence, reducing the electric output of the PV system. Decreasing these losses are possible by increasing the inter-row spacing however, on the expense of land, cabling cost and associated system losses. As shading losses in PV systems was the prominent concern, many articles are published on this topic, including publications on row spacing. Less attention was paid in the past to masking losses, constituting a larger component of radiation losses. The present study shows that masking losses exceed by far the shading losses for both isotropic and anisotropic diffuse radiation models. Consequently, this study proposes to use an acceptable level of masking losses as a criterion for the spacing between the PV rows. Assuming an yearly acceptable 1.5% masking losses, for a given PV system design for example, the inter-row spacing is 1.344m, the shading losses are 0.309% and the global losses are 1.809%, at latitude 32⁰N.