Verdant Power’s grid-connected tidal power demonstration project in New York City has exceeded performance projections by every measure as it reaches the record for the most marine renewable energy produced in the United States.
The three turbines on a novel mounting system have exceeded energy output by 40%, generating over 275MWh in eight months of continuous operation – a record for marine renewable energy production in the United States, the company claims.
Equally important, the system has been highly reliable and predictable, and has achieved operating cost targets, according to Verdant Power.
As the first U.S. commercially licensed tidal power project site, the company’s Roosevelt Island Tidal Energy (RITE) project activity is a demonstration of its fifth-generation tidal turbines integrated with its TriFrame mounting system – the next step to profitable commercial operations around the world.
Successful maintenance operation
With the support from the U.S. Department of Energy’s Water Power Technologies Office and New York State Energy Research and Development Authority, Verdant Power recently demonstrated a mid-point maintenance cycle on its tidal power system during the ongoing one-year demonstration.
The company’s strategy for maintaining an array of tidal turbines is to retrieve and replace (R&R) them and recommission the operating TriFrame system.
In the normal operation of an array, a service interval of five to seven years would be targeted for the execution of an R&R. As such, during a 20-year life, the company would conduct this exercise twice as planned maintenance, according to John Banigan, Verdant Power’s CEO.
As part of this mid-point maintenance cycle, one turbine was removed from the TriFrame and replaced with a ready spare under a collaborative project with the National Renewable Energy Laboratory (NREL).
“The spare turbine is equipped with thermoplastic blades for comparative analysis and is projected to represent considerable industry advancements in terms of cost to manufacture and lesser penetration of salt water, resulting in extended life span and recyclability”, Banigan said.
Over the current deployment period, NREL’s data acquisition system will measure blade loads for the fourth turbine.
Following the deployment, the blades will return to NREL for structural validation and material characterization to help researchers better understand why certain materials perform better in seawater than others.
Power performance assessment complete
In another world’s first, Verdant Power’s RITE Project tidal system performance was independently confirmed over a 39-day test period by Scotland’s European Marine Energy Centre (EMEC) under the new International Electrotechnical Commission (IEC) international standard.
The electrical power output of each turbine was measured and analysed to develop power and efficiency curves for the turbines.
As the first authorized Renewable Energy Testing Laboratory, EMEC confirmed the high availability and water-to-wire efficiencies, including all losses, of over 50%.
To remind, the deployment of Verdant Power’s turbine array took place on 22 October 2020, while the units started providing electricity seven days later to Roosevelt Island through a distributed generation connection to Con Edison’s New York City grid.