The word heat rate can be used in the context of thermal power plants. As we may know, these power plants convert heat energy stored in the fuel (such as gas, coal, oil and so on) into electricity (with the unit - kWh).The amount of heat needed to obtain 1 kWh (which is also known as a Unit) of electricity is referred to as heat rate. Its unit is given as kCal/kWh (where in some contexts, it is kJ/kWh). The United States Energy Information Administration (EIA) expresses the heat rates in British thermal units (Btu) per net kWh generated (net heat rate formula).