Abstract: The solar thermal energy resource situation in Nigeria including the estimated potential and available amount of the resource are presented in this study. The status of the database is discussed indicating its degree of adequacy and an identification of the gaps. The National Energy Policy Document states that Nigeria lies within a high sunshine belt and within the country; solar radiation is fairly well distributed. The annual average of total solar radiation varies from about 12.6 MJ m^-2 day (3.5 kWh m^-2 day) in the coastal latitudes to about 25.2 MJ m^-2 day (7.0 kWh m^-2 day) in the far North. Assuming an arithmetic average of 18.9 MJ m^-2 day (5.3 kWh m^-2 day), Nigeria therefore has an estimated 17, 459, 215.2 million MJ day^-1 (17.439 TJ day^-1) of solar energy falling on its 923,768 km² land area. Energy is one commodity on which the provision of goods and services depend, its availability and consumption rate is an economic index to measure the development of any community. In Nigeria, there is a limitation to power supply from the National grid which has adversely affected the economic and social development of the populace. This really necessitates the need for decentralized power source as a viable alternative to which solar/thermal energy readily fits in.