A solar reflector for an evaporator in a heat pump system. The evaporator has heat transfer plates and is located in an outdoor environment. The solar reflector has a curved surface configured to reflect solar radiation to the heat transfer plates of the evaporator. The curved surface can be in the shape of a truncated parabola. The curved surface can also be curved in a dish-like shape defining an upper perimeter and a lower perimeter, and the lower perimeter defines a bottom opening configured to receive the evaporator. The solar reflector can also be made of a plurality of partially overlapping curved surfaces configured to reflect solar radiation to the heat transfer plates of the evaporator. In this case the solar reflector includes a hinge ring, and each of the curved surfaces are hingedly attached to the hinge ring. Preferably the hinge ring defines an opening to receive the evaporator.