  Due to the increasing proportion of distributed photovoltaic (PV) production
in the generation mix, the knowledge of the PV generation capacity has become a
key factor. In this work, we propose to compute the PV plant maximum power
starting from the indirectly-estimated irradiance. Three estimators are
compared in terms of i) ability to compute the PV plant maximum power, ii)
bandwidth and iii) robustness against measurements noise. The approaches rely
on measurements of the DC voltage, current, and cell temperature and on a model
of the PV array. We show that the considered methods can accurately reconstruct
the PV maximum generation even during curtailment periods, i.e. when the
measured PV power is not representative of the maximum potential of the PV
array. Performance evaluation is carried out by using a dedicated experimental
setup on a 14.3 kWp rooftop PV installation. Results also proved that the
analyzed methods can outperform pyranometer-based estimations, with a less
complex sensing system. We show how the obtained PV maximum power values can be
applied to train time series-based solar maximum power forecasting techniques.
This is beneficial when the measured power values, commonly used as training,
are not representative of the maximum PV potential.
