Solar-PV – introduction 3
© EMD International A/S • www.emd.dk • windPRO 4.1 • September 2024
14.1 Solar-PV – introduction
14.1.1 Introduction to Solar-PV
The windPRO Solar-PV module allows users to design and perform energy yield calculations
for a Solar Photovoltaic (PV) plant.
A PV plant can be designed in multiple areas with individual properties (panel type, tilt,
row distance etc.) making it easy to handle also complex plant designs.
The designed plant can be visualized using the windPRO PHOTOMONTAGE module.
The Solar-PV module can handle any size of PV-plant, from just one panel to millions of
panels. The calculation time can although limit what is realistic to calculate. This is solved
by a reference panel calculation when plants get very large. When enabled, just one panel
(table) is calculated and scaled up to the full area. The tool will give a warning if a
calculation is started with more than 300.000 panels (~200 MW), which will take 10-15
hours to calculate with a 20-year time series on a standard PC. With the reference panel
calculation method, calculation time is less than 1 minute. It is possible to calculate some
areas with reference panels, other as individual panel calculation and thereby get correct
shading calculation where obstacles are near panels, while still working with a reasonable
calculation time. We are constantly working on improving the calculation time.
windPRO handles both bifacial (panels utilizing irradiance at the rear side of the panel) and
tracking plants. Tracking can be set to manual (seasonal tilt adjustment for panels facing
Equator) or as continuous (for e.g., East-West facing panels, becoming more and more
common due to higher electricity prices morning and afternoon). Not all tracking variants
are included at present, only the most common.
The module can optimize tilt angles for fixed tilt plants or season tracking plants based on
an optimizing algorithm. This algorithm uses the time series irradiance data and all losses
to find the tilt angles giving the highest annual energy production after loss deduction. For
continuous tracking systems backtracking is included in the tilt angle calculations, so panel
shading is prevented when the solar angle is low.
Starting from windPRO 4.0 a more advanced optimization tool is available, where multiple
parameters of the layout can be optimized: tilt, row spacing, azimuth, number of vertical
panels and AC/DC ratio of the plant. The objective of the optimization can be maximizing
annual energy production (AEP), minimizing levelized cost of electricity (LCOE) or
maximizing net present value (NPV).
The basic philosophy of the module is it to make it quick and easy to design PV-plants and
to calculate the expected energy production accurately. The module enables handling and
analysing the meteorological input data for the calculation, because poor data quality can
lead to significant bias and high uncertainty in any calculation. Calibration of long-term
model data with local short-term local measurements is an option. The comprehensive
METEO ANALYSER tool in windPRO handles solar data just as flexibly and comprehensively
as it does for wind data.
The calculation of the shading reductions is of high importance when designing a plant.
This is where the plant developer can make a difference. Panel shading by many rows in a
field or on a flat rooftop, is the major loss component for modern PV plants, and this is
handled quickly and easily in the module by testing different alternatives. In addition, as a
windPRO speciality; how much shading loss will wind turbines cause, when the PV-plant is