Total energy of the domain for different values of η. In the η = 0 experiment there is no energy transfer due to Ohmic heating, however, there are still energy losses through numerical dissipation. The total energy was calculated using the Poynting flux on the boundary, therefore, any numerical energy losses in the domain are accounted for. The plots have been normalised by , which gives the total energy input from the driver in an equivalent but linear and ideal set-up.