A system for roasting particulate material, such as coffee or cacao beans, grains, or malt, includes a photovoltaic unit configured for generating electricity from the solar radiation, a heat storage device comprising at least one phase change material, a roasting device configured for roasting said particulate material, a thermal circuit connecting the heat storage device to the roasting device and configured for circulating a fluid through the roasting device, and an electrical circuit connecting the photovoltaic unit to the heat storage device and configured for exchanging heat with said at least one phase change material.