This study investigates the use of solar energy for producing biofuels through pyrolysis. A model is outlined to define the ideal parameters and evaluate the annual performance of a solar pyrolysis system. The model is demonstrated by considering a linear Fresnel reflector (LFR) system operating in Seville, Spain. The ideal operating temperature and total residence time were determined to be 571 K and 149 min, respectively. Subsequently, an LFR system was sized to have a total reactor length of 3.23 m, a polar inclination angle of 39 and an effective concentrating aperture area of 4.55 m(2). The maximum char yield fraction was found to be 40.8 wt.%; however, the annual variability of the solar input resulted in the system producing 1375 kg of biochar from 13.9 t of biomass. The model developed in this study can be applied to evaluate a range of solar thermal technologies in other localities for producing char, gar and oils through the pyrolysis process. (C) 2017 Elsevier Ltd. All rights reserved.