The characteristics of photovoltaic (PV) panels in the field conditions are to be obtained using a fast varying load. The paper presents a simple electronic load for testing a set of PV panels using linear metal oxide field effect transistors (MOSFETs). The proposed test set up gives the current versus voltage and power versus voltage characteristics of PV panels by quickly scanning the load. Design equations giving the MOSFET rating, and gate voltage range for obtaining a specified portion of the PV panel characteristics are derived. With additional signal processing, the maximum power available from the panels and the corresponding current and voltage values are also obtained. Experimental waveforms obtained on the test circuit are presented. (c) 2005 Elsevier B.V. All rights reserved.