Dynamic Electrical Ratings and the Economics of Capacity Factor for Wave Energy Converter Arrays

Wave Energy Converters (WECs) have been in development for several decades with some devices now coming close to commercial realities. As such, pilot projects are being developed, particularly in the UK and Ireland, to deploy WECs on a pre-commercial array scale. The ultimate ambition is to have multiple WECs installed in a ‘wave farm’ in a similar fashion to offshore wind farms. For large scale wind farms the inter-array and export electrical systems can represent more than 20% of the project’s capital expenditure. Submarine power cables account for a large proportion of this cost. The same is expected to hold true for wave farms. This paper investigates the possibility of underrating and dynamically rating the electrical inter-array and export cable systems for wave farms in order to assess the cost savings that can be made. This paper will also look at a simulated WEC array power output time series. The aim is to establish whether the electrical equipment, particularly submarine cables, will operate outside its design parameters if under-rated based on maximum continuous current. This paper also investigates the WEC capacity factor effect on the overall economics of the array electrical system. It is concluded that cost savings could be made in the electrical network by utilising one, or a combination of, the outlined strategies.