Two 20 W copper indium gallium diselenide photovoltaic modules were subjected to a thorough indoor assessment procedure, followed by outdoor deployment at the Nelson Mandela Metropolitan University as part of an ongoing study. The initial indoor measurement of maximum power output (P(MAX)) of one of the modules was considerably higher than the manufacturer's rating (E.E. van Dyk, C. Radue and A.R. Gxasheka, Thin Solid Films 515 (2007) 6196). The modules were deployed on a dual-axis solar tracker and current-voltage characteristics were obtained weekly. In addition to the normal PV parameters of short-circuit current, open-circuit voltage. PMAX, fill factor and efficiency, shunt and series resistances were also monitored. The performances of the two modules are compared and analyzed and the results presented in this paper. (C) 2008 Elsevier B.V. All rights reserved.