The control strategy for a photovoltaic (PV) system with a hydrogen (H-2) subsystem consisting of an electrolyzer, pressurized hydrogen gas storage, and fuel cell has been investigated. Detailed computer simulation models for TRNSYS have been developed, tested, and verified against a reference system, namely the PHOEBUS plant in Julich, Germany. The basic control strategy and main logical control variables for a PV-H-2 system are described. System performance indicators, parameters, and constraints that can be used to analyze the performance of PV-H-2 systems have been identified. The results from a time series simulation for a typical year are presented. Finally, the importance of selecting smart control strategies is demonstrated. (C) 2003 Elsevier Ltd. All rights reserved.