Yes, it's fairly easy to convert heat to cold. In away that's what's happening with standard air-conditioning powered by electricity generated by burning coal, except the heat is converted to electricity first, to drive a heat pump.
Thermodynamics limit the ultimate maximum efficiency of the system.The higher the temperature differential on the hot to ambient side and the lower the temperature differential on the cold to ambient side, the more efficient in terms of Watts of heat in, compared to Watts of cooling, it can be. For example, if the ambient temperature is 30°C and your heat source is 300°C, you'll get more cooling power, per Watt than a 100°C heat source and if you only need to cool to 20°C it will be more efficient, than cooling to -20°C.
The question is whether it's any more efficient compared to existing technologies such as absorption cooling?