The SEAS PhotovoltaicOntology Ontology describes solar panels and its components as electric power systems.
The class of electronic devices or circuitry that change direct current (DC) to alternating current (AC). (source: The Authoritative Dictionary of IEEE Standards Terms, Seventh Edition, IEEE Press, 2000, ISBN 0-7381-2601-2, page 588)
sub class of: ElectricPowerTransformer
Solar arrays consist of one or many solar panels.
Solar cells belong a solar module.
Solar modules consist of one or many solar cells.
Solar panels consist of one or many solar modules.