Most of the work done on solar
stills (Cooper, 1970; Hirschmann and Roefler,
1970) used the expressions for internal heat transfer
coefficients as developed byDunkle (1961). But due
to certain limitations of these expressions, Kumar
and Tiwari (1996) developed a model based on
regression analysis that was free from the limitations of the expressions given by Dunkle (1961).
LaterTiwari et al. (2003)have studied the convective heat transfer coefficient for passive/active solar
still by using inner glass cover temperature for
limited period of operation. Recently Delyannis
(2003) and Tiwari et al. (2003)presented a historical
background and present status of desalination and
renewable energies.