In this research, for the study of solar radiation energy and estimation of GHI in the area of radiation component, data were collected for the years during 2005–2014 from ECMWF database. To investigate the ocean thermal energy conversion, vertical changes of water temperature were studied using UNESCO data as seasonal thermocline for the Caspian Sea. Moreover, to investigate the possibility of the use of ocean thermal energy conversion (OTEC) in the offshore regions, the surface water temperature data obtained from ECMWF from 2005 to 2014 was used, the number of days that the ocean thermal energy conversion could be used in the field was calculated. The findings show that the use of the ocean thermal energy conversion is only possible in the southern basin during July–September. The fields of Sardar Jangal, Shahdeniz, Ganeshli and Azari are the only oil and gas fields that can use this energy 54, 34, 31 and 31 days a year, respectively. In the field of solar radiation, the southern basin with an annual average of 1550 kWh/m2 is the most suitable basin and Sardar Jangal field with the monthly average of 131.81 kWh/m2 is the most suitable field for the use of solar energy.