The energy input into a piece of Carbon Fibre Composite due to a lightning strike was investigated. The lightning strike has been broken down into its separate components, i.e. current impulses and the plasma heat flux. The energy deposited into the system from each of these components was examined separately. Before the energy input due to the current impulses could be considered, the AC electrical behave of CFC panels was investigated. The experiments showed that there were no capacitance or inductance effects in the 1 Hz - 1 kHz window. This means the CFCs can be treated as a purely DC resistive material (in this freq. range). A quasi-static DC model was then developed to determine the energy input from each of the lightning components. The model predicts that with CFCs the majority of the damage is caused by current component A