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Lanai High-Density Irradiance Sensor Network for Characterizing Solar Resource Variability of MW-Scale PV System « Manual « Downloads

Date postedApril 9, 2012
Downloaded441 times
CategoriesManual, Renewable Energy, Solar Energy, Photovoltaic


Sandia National Laboratories (Sandia) and SunPower
Corporation (SunPower) have completed design and
deployment of an autonomous irradiance monitoring
system based on wireless mesh communications and a
battery operated data acquisition system. The Lanai HighDensity Irradiance Sensor Network is comprised of 24
LI-COR® irradiance sensors (silicon pyranometers) polled
by 19 RF Radios. The system was implemented with
commercially available hardware and custom developed
LabVIEW applications. The network of solar irradiance
sensors was installed in January 2010 around the
periphery and within the 1.2 MW ac La Ola PV plant on
the island of Lanai, Hawaii. Data acquired at 1 second
intervals is transmitted over wireless links to be timestamped and recorded on SunPower data servers at the
site for later analysis. The intent is to study power and
solar resource data sets to correlate the movement of
cloud shadows across the PV array and its effect on
power output of the PV plant. The irradiance data sets
recorded will be used to study the shape, size and velocity
of cloud shadows. This data, along with time-correlated
PV array output data, will support the development and
validation of a PV performance model that can predict the
short-term output characteristics (ramp rates) of PV
systems of different sizes and designs. This analysis could
also be used by the La Ola system operator to predict
power ramp events and support the function of the future
battery system. This experience could be used to validate
short-term output forecasting methodologies.

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