Dimensioning the equipment of a wave farm: Energy storage and cables

Still largely untapped, wave energy is particularly abundant and may represent an important share in the energy mix of many countries in the future. However, the power fluctuations generated by most wave energy converters with little to no storage means or without suitable control strategies may deteriorate the power quality of the local network to which wave farms will be connected. They may in particular generate an excessive level of flicker. The minimum amount of storage required for a wave farm to be grid compliant with respect to typical flicker requirements was investigated and is presented in the first part of this study. Besides giving rise to power quality issues, the rapid and high amplitude power peaks generated by wave devices may also render more complex the optimal dimensioning of the wave farm electrical components, whose cost is highly dependent on their power rating. This statement applies also to submarine cables, as the maximum current flowing potentially through them seems to be no longer a relevant criterion for determining their optimal current rating. Hence, the second part of the presented study focuses on the minimum current rating required from a submarine cable to avoid its thermal overloading.