This paper investigates the determinants of solar photovoltaic (PV) deployment in the electricity mix for a panelof OECD and BRICS countries from 1997 to 2016 by paying particular attention to the impact of oil market con-ditions. Relying on a nonlinear, regime-switching specification, we show that rising oil prices stimulate PV de-ployment only if their growth rate exceeds 6.7% per annum. Although wefind that various other determinantsmatter—with the influence of some of them depending on the situation on the oil market—public policies playa crucial role.