Related to Fossil fuel energy

Fossil fuel means natural gas, petroleum, coal, or any form of solid, liquid, or gaseous fuel derived from such material.
Fossil fuel-fired means the combustion of fossil fuel or any derivative of fossil fuel, alone or in combination with any other fuel, independent of the percentage of fossil fuel consumed in any calendar year (expressed in mmBtu).
Thermal energy means the thermal output produced by a combustion source used directly as part of a manufacturing process, industrial/commercial process, or heating/cooling application, but not used to produce electricity.
Geothermal energy means energy contained in heat that continuously flows outward from the earth that is used as the sole source of energy to produce electricity.
Useful thermal energy means, with regard to a cogeneration unit, thermal energy that is:

Fossil fuel energy definition