This paper explores energy and physical resource limitations to transitioning from fossil fuels to the large-scale generation of electricity with photovoltaic arrays. The model finds that business as usual models, which involve growth rates in world electricity demand of between 2% and 3.2% p.a., exhibit severe material difficulties before the end of this century. If the growth rate is lowered to 1% p.a., then it may be possible to reach the year 2100 before such difficulties, but it is likely that material constraints will occur early the next century. Steady state scenarios show that silicon based photovoltaic panels could, however, displace fossil fuels before the middle of the century, providing around the same order of magnitude as present (2010) world electricity demand. Scenarios also show that outcomes will be highly dependent upon the rate of improvement of photovoltaic technologies. The analysis does not contend that silicon PV technology is the only technology that will or can be adopted, but as the embodied energy content per kWh generated of this technology is similar to other renewable technologies, such as other solar technologies and wind, it can provide a baseline for examining a transition to a mixture of renewable energy sources. (C) 2010 Elsevier Ltd. All rights reserved.