**1.1 Solar energy applications**

Specific areas of solar technology application has been identified to include electricity supply during power outages, telephone installations, industrial sector and drying of agricultural and forestry products like cocoa, timber etc (Akarakiri and Ilori, 2003). For instance, in Nigeria, Nitel powered the Ugonoba and the Gewadabawa repeater stations in 1997; more than 50 repeater stations in the Nigerian Network were powered by PV systems (Coker, 2004).

Solar energy has been limited mainly to low grade thermal applications in the Sub Saharan African region. For instance over 10,000 units of solar water heaters have been installed in Botswana, Zimbabwe, and South African (Akarakiri and Ilori, 2003). A project funded by the Agency for International Development (AID) in Tangaye, Africa provides fresh water and runs a grain mill for commercial production of flour (Maycock and Stirewait, 1981).

Several researches have been undertaken concerning the direct generation of electricity using the heat produced from nuclear reactors, kerosene lamps, firewood and biomass. The development of improved materials, use of multi-junction devices and novel cell designs to capture a higher proportion of the solar spectrum and use of concentration (Fresnel) lenses to focus the sunlight to high efficiency cells are areas of rapid development (Duffie, and Beckman, 1976).

The study of thermoelectric materials is a very active area of modern research that combines aspects of physical chemistry, solid state physics, and materials science. A thermoelectric material is a material that converts heat to electricity and vice versa. The main motivation for studying thermoelectricity is to find ways to improve their performance to better implement them in practical systems. The concept of thermoelectricity, a process that converts heat energy into electrical energy by using the Seebeck effect, has been used in agricultural operations.
