The thermal performance of a prototype solar cooker based on an evacuated tube solar collector with phase change material (PCM) storage unit is investigated. The design has separate parts for energy collection and cooking coupled by a PCM storage unit. Solar energy is stored in the PCM storage unit during sunshine hours and is utilized for cooking in late evening/night time. Commercial grade erythritol was used as a latent heat storage material. Noon and evening cooking experiments were conducted with different loads and loading times. Cooking experiments and PCM storage processes were carried out simultaneously. It was observed that noon cooking did not affect the evening cooking, and evening cooking using PCM heat storage was found to be faster than noon cooking. The cooker performance under a variety of operating and climatic conditions was studied at Mie, Japan. (c) 2004 Elsevier Ltd. All rights reserved.