Abstract
Halagonia Tidal Energy Limited (HTEL) worked with OERA (now Net Zero Atlantic), Fundy Ocean Research Center for Energy (FORCE) and other Industry members on the Pathway Program. HTEL was responsible for designing, assembling, and delivering to OERA a fully functional, multi-sensor monitoring platform design. The fully functioning platform has now been successfully demonstrated in the tidal stream at the FORCE site in Parrsboro.
HTEL used an existing platform frame designed to be used at the FORCE site, owned by FORCE, as the starting point for the monitoring platform. Using the best information available at the time, HTEL acquired sensors to be used by the project. The layout of the sensors on the platform was designed to ensure the proper clearance, access and coverage specific to each sensor. These sensors were attached to the platform using bespoke brackets designed and manufactured by Precise Design; the brackets were specified to withstand the expected forces at the test site. The sensors were integrated through a common user interface by JASCO Applied Sciences (JASCO). The data management plan was developed and executed by Strum Engineering. A corrosion analysis was completed by Corrosion Services to identify the optimum size of and locations for sacrificial anodes to provide cathodic protection to the platform, sensors, fixings and connectors. MacArtney Canada Ltd (MacArtney) completed the cable termination of the subsea cable and other sensor cables as required. MacArtney also designed and manufactured the multiplexor for the system. This multiplexor split the power from the power supply to each sensor and provided the fibre connection for data transfer from each sensor to the workstation ashore. The Marine Operations (deployment, recovery, etc.) were planned and managed by Halifax Offshore Consulting, supported by Huntley’s Dive and Marine and Dominion Diving. Seaforth Geosurveys identified the best route for the subsea cable from the test site back to shore. Enginuity designed and manufactured bend restrictors to protect the subsea cable at the platform connection point.
The monitoring platform was deployed at HTEL’s Berth E located in the FORCE Crown Lease Area (CLA) at the test site in the Minas Passage. This was the first time a monitoring platform had been deployed at the FORCE site, at this distance offshore and depth, cabled back to the FORCE Visitor’s Centre. It was a successful demonstration of the ability to collect information about fish presence at the FORCE test site from a tethered platform. The tether to shore allowed the team to modify sensor settings to optimize sensor performance for any given period of time or research purpose. This was a demonstration of a critical ability for instream tidal turbines at the FORCE site; Environmental Effects Monitoring is a key requirement for the FORCE EA, bertholder Marine Licence and DFO Authorization.
The platform was successfully deployed initially on 2 August 2021, however the project was unable to establish communications and, after thorough troubleshooting, recovered the platform for investigation on 14 September 2021. Following a fault analysis, a number of components were identified to either be refurbished or replaced. The platform was redeployed on 26 November 2021. The project completed its initial testing objectives on 10 December 2021 and commenced a full data collection program. Ever since, the platform has continued to collect data, with gaps that were caused by power loss at the Visitor’s Centre during winter storm outages. The project encountered a number of different events during the data collection period, all of which will be discussed in later sections of this report.
Recovery of the platform is pending due to a series of weather delays. The most recent attempt, on 24 March, was unsuccessful as the recovery buoys had released in early February, likely as a result of a failure in the flap designed to keep them spooled. The buoys detached prior to a recovery being possible. The project is intending to grapple for the platform’s recovery line and recovery the platform at the next available opportunity. Currently, this is planned to occur during the 7 April neap tide cycle, with a back up planned for on or around 22 April.