Two University of New Hampshire (UNH) doctoral candidates have designed an underwater turbine that could revolutionise what we know about tidal energy.
Parviz Sedigh and Mason Bichanich – in partnership with the National Renewable Energy Laboratory (NREL), Sandia National Laboratories, and the Pacific Northwest National Laboratory (PNNL), and with funding from the US Department of Energy’s Water Power Technologies Office – have designed an axial-flow tidal turbine that’s fully instrumented to collect data at the mouth of the Piscataqua River in New England.
Using NREL’s Modular Ocean Data Acquisition (MODAQ) setup, their turbine will supply data for the nascent field of tidal energy, a clean energy source that could potentially power up to 21 million homes in the USA.
The 25-kilowatt turbine – about the size of a harbour seal and oriented like an underwater wind turbine – will be on triple duty once deployed. Besides producing valuable data, it will help power a busy drawbridge and support community education through UNH’s Living Bridge Project.
Sedigh and Bichanich needed their turbine to sense and collect data. It would have to protect many sensor types, along with their wiring and controls, all while powering small loads and dodging debris in the turbid estuary, before the Piscataqua meets the Gulf of Maine.
They picked through a conceptual scrapyard of past designs, drawing inspiration when possible or adding a unique spin when necessary. ‘We couldn’t pull one-to-one from past designs because of scale. Sometimes the costs don’t make sense,’ Bichanich explained.Collaborating closely with NREL, PNNL, and Sandia, the team eventually settled on a viable 3D model.
The new turbine is slated for initial testing this year in Portsmouth, New Hampshire, beneath the Memorial Bridge, which was rebranded as the Living Bridge by the Atlantic Marine Energy Center (AMEC) to promote its role as a pillar of public science.
Compared to a prior research turbine beneath the bridge, the incoming turbine is technologically unique in that it is highly instrumented to collect as much data as possible. The kernel of this data acquisition is NREL’s MODAQ, which contains open-source software for logging performance data.
‘With this project, NREL is sharing its past experience and technological skills with AMEC and its students in the hopes that the Living Bridge platform can be used for future turbine testing and education,’ said Aidan Bharath, project lead at NREL. ‘Bichanich and Sedigh are building the foundation of a research platform that will allow future turbine components to be tested and comprehensively monitored.’
Data from the MODAQ system will be openly available through the Water Power Technologies Office’s Marine and Hydrokinetic Data Repository. Besides tracking strain on the turbine, power output and environmental conditions, equipment such as PNNL’s acoustic camera will also watch upstream for floating perils and collect data on tidal debris. ‘We got hit by a lobster pot the other day,’ Bichanich said, also noting the dangers of fallen trees and bobbing icebergs.
As the team approaches the finish line, they recognise how important close collaboration has been. ‘Sedigh and I are each turning the wrench as much as the other,’ Bichanich said.
‘One person can come up with an idea, but two of us can try and multiply the idea to get an optimised outcome,’ Sedigh added.