This paper presents a review of a standalone and grid-connected hybrid renewable energy system (HRES) to supply AC loads. The configuration of the HRESs and interfacing power converters for connecting the energy sources to the AC bus is extensively discussed. An overview of the control concepts in an HRES and the application of the appropriate control schemes for system stabilization, effective injection of high quality power and proper load sharing are discussed. The different approaches for HRES design and control strategies for power converters in the recently published literature are also briefly addressed. Finally, this paper highlights the future developments in HRESs to increase the utilization of power generated from renewable energy sources (RESs).