The use of solid rotor and pole-plate synchronous machines has several advantages, among which is the fact that it provides a more robust rotor compared to laminated equivalents. This paper investigates the time and space harmonic losses in solid rotor synchronous machines. The work considers the use of copper coating on the pole-plates, studying the effect that this design modification has on the losses. A recommendation is given based on this study, which is considered to reduce the time harmonic losses without detrimental effects as far as the space harmonic losses are considered.