INVESTIGATION OF EFFICIENCY ASPECTS IN 3×3 PHOTOVOLTAIC PLANT USING MODEL OF SHADING

Abstract

Abstract
Solar irradiation is the most affordable renewable energy source, implementable even on household level. The
considerably lower cost of setup and maintenance compared to the other renewable energies makes it a
preferable choice in regions with lot of sunny days throughout the year. One of the main R&D aspects of
interest of the Photovoltaic (PV) technologies is the efficiency of the PV conversion, which is dealt with on
material level. Additional efficiency aspects could be a field of research in support to higher energy
production. One of them is the land use efficiency of the utilized plot surface. Namely, the usual approach in
populating the plot used by the plant is with row and column distances that guarantee no inter-shading among
the panels. This paper presents results of research proposing use of denser panel population in the plot, with
allowed inter-shading which under some approximation provides calculations of lower individual panel
efficiency but much higher overall land use efficiency. The research project proposes an inter-shading model
in a 3×3 PV plant, which can be validated in CAD applications. A clear-sky irradiation model is then used to
estimate plant's power at certain moment in the year, and calculation of energy production. Sun position and
its incidence angle are calculated using a verified model. The analytical software uses the following input
parameters - plant geo-location (latitude, longitude, time zone); panel geometry (width, height); plant
geometry (inter-row and inter-column distances, panel inclination angle); and date and time. The intershading
model results in total plant exposed PV surface to direct solar irradiation, as well as in the total
shaded PV surface receiving diffuse (and reflected) radiation. The energy model can then be used for power
and energy calculations, as well as optimal inclination, inter-row and inter-column estimations. If panel
technologies allow small segmentation with protective diodes implementing approximation that whole directly
exposed surface performs PV conversion, then allowed inter-shading and thus denser panel populated plant
plot may prove cost-effective.
Key words
solar irradiation, photovoltaic conversion, intershading, land use efficiency.