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Photovoltaic Resource Modeling for Long-term Simulation. Rajesh Bhana Power and Energy Systems Research Group. Photovoltaic production and load. Sources: ERCOT and NREL. Probabilistic simulation framework. Nature of the problem.
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Photovoltaic Resource Modeling for Long-term Simulation Rajesh Bhana Power and Energy Systems Research Group
Photovoltaic production and load Sources: ERCOT and NREL
Nature of the problem • Incorporate photovoltaic (PV) production in a probabilistic simulation framework • Identify patterns of PV production • Capture the variable, intermittent and time-dependent characteristics of PV production
Drivers for scaling • Ability to effectively compare data of different magnitudes and durations • Computational tractability in the representation of the time-dependent, variable and intermittent PV output data
Pattern identification • Separate data into four seasons • Groups (clusters) with associated probabilities • K-means clustering
Euclidean distance • Distance between two output characterizations • Sum of the square of the differences
Incorporation of probabilistic model into framework • Load conditioned over each hour • PV production subtracted from the load • ‘Controllable load’ • Representative weeks cover shorter durations • Framework applied to obtain reliability, economic and environmental effects
Future Work • Determine a more accurate ‘clear-day’ • Develop and apply a model to represent distributed PV sources • Apply a solar thermal model • Capture storage capability
Radiation measurement devices Pyranometer Pyrheliometer http://www.volker-quaschning.de/fotos/messung/index_e.php
K-means clustering • K clusters • Result dependent on initial centroid • Euclidean distance • Iteratively: • Characterizations are grouped in clusters • Cluster centroids are recalculated • Process continues until there is no change in the membership of the clusters.
k-means clustering example • Four data points, two clusters • Data points: {1, 3, 8, 10} • Initial centroids: 1 and 3 • Allocation: 1 {1} and 3 {3, 8, 10} • New centroids 1 and 7 • Allocation: 1 {1, 3} and 7 {8, 10} • New centroids: 2 and 9 • Allocation: 2 {1, 3} and 9 {8, 10} • No change in allocation => Complete