The electrical systems technical working group is one of five technical working groups of the Offshore Wind Accelerator (OWA), consisting of experts from each of the OWA’s partner organisations and the Carbon Trust. It aims to increase the efficiency and reliability of systems that collect and transmit electricity for offshore wind, and to increase their cost effectiveness.
As windfarms move further offshore, and turbine ratings continue to increase, considerable challenges and opportunities are presented to reduce the costs of electrical systems through the implementation of innovative solutions. The group aims to tackle these problems with projects that:
- Improve efficiency and performance of electrical systems
- Assess opportunities for offshore wind to provide system services
- Reduce direct costs of electrical components
Research areas
The electrical systems technical working group conducts projects in a number of key research areas.
HVDC transmission
There is increasing demand for safe and efficient grid connection of offshore wind farms using HVDC transmission technology, especially as projects move further from shore. The electrical systems technical working group is conducting a number of studies to advance research in this area, including investigations into the potential for medium voltage DC (MVDC) array cables to connect wind turbines direct to shore, which could provide dramatic cost savings by negating the need for offshore substations.
Read our 2018 refresh study, which looked at the advancements in DC technology in recent years.
System services
In order to maintain long term offshore wind power competitiveness and grid stability with increasing amounts of renewable generation, it is important for offshore wind to participate in solving current and future grid integration challenges. The OWA has supported research in this area with investigations into the potential of offshore wind turbines to provide black start capability, and associated controls and protocols that would be required. Beyond black start capability, the OWA has also assessed opportunities for offshore wind to participate in additional ancillary and flexibility services markets, and innovation requirements to realise this participation.
Innovative electrical components
The electrical system technical working group is continually investigating opportunities to reduce costs of, and provide innovative alternatives to, conventional electrical components, which can comprise a significant proportion of offshore wind farm capital expenditure.
In 2015, the OWA launched a study to further investigate the benefits of the Offshore Transformer Module (OTM) concept, a new kind of substation, and a discretionary project to support its market introduction. The project investigated the engineering and regulatory challenges faced during design and refinement to ultimately allow a better industry understanding and acceptance of this cost saving solution. The objective of the OTM discretionary project is to share knowledge of the first full-scale development of the OTM module for the Beatrice offshore wind farm in Scotland. The OTM did demonstrate cost savings and is now an option for industry.
More recently, the OWA has commenced an investigation into the potential for a magnetically-controlled shunt reactor (MCSR) to play a role in reactive power compensation of an offshore wind farm, including investigations into grid code compliance, and potential cost benefits of such technology. Initial expectation is that MCSR would be cheaper and have a smaller physical footprint (size) than existing technologies.
Higher voltage cables
After managing a number of studies investigating the potential benefits of upgrading from existing 33kV cable technology to 66kV it became clear that these higher voltage electrical arrays would offer benefits that would increase cable reliability and efficiency, leading to cost reductions. To encourage the development of a competitive 66kV cable market, the OWA launched a competition for innovative 66kV inter array cables. This resulted in the OWA supporting the testing and qualification of four different designs from JDR, Nexans and Prysmian, with the first cables becoming commercially available from 2015.
Regulation
The continued success of offshore wind power can be facilitated further by ensuring regulation keeps pace with industry developments. The electrical systems technical working group has conducted research studies into improved regulatory environments for offshore wind connection and integration.
Contact
For any questions relating to the electrical systems working group please contact owa@carbontrust.com.
