Urgent action is needed to ensure sufficient supply of export cables for offshore wind and to avoid global demand outstripping supply by as much as 85% by 2015, according to research published by UK seabed owner, The Crown Estate.
Global demand from offshore wind developers that are pursuing "high certainty" projects is expected to exceed supply by 33% during the period 2012-18, concludes a report produced for The Crown Estate by Cable Consulting International (CCI).
In the first study of its kind investigating global supply-demand scenarios for offshore wind export cables and associated equipment, such as interconnectors, CCI concludes that a "significant supply chain gap exists". At worst, demand will exceed supply by 85% in 2015.
Some additional capacity is expected to become available from 2016. However, CCI’s report notes that cable manufacturers are reluctant to invest in new production capacity due to uncertainty about project approvals and timing. The UK government's recent decision to block construction of Centrica's Docking Shoal project is quoted as an example of how demand for cables can be revised downwards.
"Cable manufacturers have had bad experiences from demand collapse in the past and, therefore, they are reluctant to scale up," explained Crown Estate development manager, Matt Bleasdale, speaking about the research at Windpower Events’ recent offshore cable installation, engineering and maintenance event in London. "New manufacturers need to be encouraged and existing manufacturers encouraged to increase capacity."
CCI urges UK offshore wind developers to "convince manufacturers to act now" and to give cable companies as much certainty as possible about project timetables and requirements.
Other options for reducing the looming supply gap are explored, including ways of bringing down demand. These include:
- increasing system voltage to cut conductor size
- reviewing cable rating on a project-by-project basis with a view to rating for smaller conductor size
- coordinating offshore network structures to minimise necessary cable quantities
- reducing AC power transmission frequency to both cut conductor size and, in some cases, the number of cables
- developing common technical specifications to speed up cable quotations and manufacture
- developing cable buying alliances that would allow developers to purchase greater volumes of the same cable design
- and shortening the length of time between issue of tender and contract fulfilment.