Offshore renewable energy brings new challenges to the design of high voltage cable systems. Unlike normal cable networks, power transfer required from the cables is  not goverened by demand, but by supply. Supply, in turn, is generally a function of natural forces, which are  predictable only statistically; individual, short term, peaks and troughs cannot be predicted.

This leads to the need for attention to cable rating, to avoid both undersizing and oversizing of cables. This is further exacerbated by the varying thermal environments along the route, often with areas of deep burial or ducting in the warmer, more thermally challenging, beach landing zones.

Undersized cables will obviously overheat and suffer reduced service life.

Oversized cables are also to be avoided especially with the increasingly high cost of copper.

 

Interarray Cables 

The smaller, medium voltage, interarray cables also pose challenges.

Firstly the question of how often to increase the conductor size along the rows of turbines.

Secondly the short cable routes and large number of end pulls. Such operations are the most critcal part, needing carefiul attention to vessel offset, catenary tension, re-termination allowances, and avoidance of unsupported cable spans.