The same ocean winds that bring relief on hot days at Shoals Marine Lab also help keep the lights on by powering the island’s wind turbine.
At Shoals Marine Lab and elsewhere, wind energy has an incredible potential to make electric grids greener by reducing reliance on fossil fuels. In a wind turbine, the movement of surrounding air spins blades connected to a generator, making electricity through motion. The summer 2022 sustainability engineering interns at Shoals Marine Lab, Zach Katz, Izzy Medeiros, Jason Shao, and Tess Hays, are working to ensure that the island’s turbine works as efficiently as possible.
Last year, Shoals Marine Lab updated its wind turbine. The interns are analyzing why there are often differences between the manufacturer’s estimate of how much energy the updated turbine would produce and how much energy is actually being produced.
“The island prides itself on its sustainability, and publishes its data on the dashboard for everyone to see, so it's important that this data is accurate,” Shao said.
Because the wind’s speed is often changing, manufacturers cannot issue estimates of exactly how much energy their turbines will produce. Instead, they tell customers what percentage of the wind’s total energy can be harnessed by the turbine. To measure how much energy an updated turbine could produce, the interns need to calculate the wind’s total power. They learned the fundamentals of wind power calculations from University of New Hampshire Mechanical Engineering and Ocean Engineering professor Dr. Martin Wosnick.
According to the interns, one possible reason for the difference between the real and estimated energy made by the wind turbine is that island engineers may not know exactly how fast the wind is blowing at the turbine. The wind speed is measured at the island’s radar tower and on a nearby island but not at the turbine itself, so the calculation of the turbine’s ideal output might be based on incomplete data. More accurate wind measurements at the turbine could help rule out whether something could be wrong with the turbine itself, rather than just with the calculations.
Shoals Marine Lab operates during the summer, so island staff raise the wind turbine blades at the beginning and end of each active season. This is a complex, labor intensive process. The hydraulic system for tilting the tower to raise and lower the blades has a design flaw - it tends to spill hydraulic fluid because the reservoir for the fluid is too small. The interns’ task is to recommend solutions so that Shoals Marine Lab staff no longer need to catch spilled hydraulic fluid in buckets.
“Our task is to analyze the wind turbine’s hydraulic system, determine what size reservoir of hydraulic fluid is needed to effectively operate it,” Katz said.
The interns researched hydraulic systems, consulting research papers and textbooks in order to devise the best possible solution for the hydraulic system issue. Eventually, they found that the fluid storage tank needs to be larger to allow for extra storage. This solution will reduce the amount of work needed to maintain the wind turbine, because someone will no longer need to hold a bucket to catch the fluid.
“With a small population on the island, it’s important to make sure that we don’t need the entirety of the professional staff to raise and lower the blades,” Hays said.
As the interns learn how to improve existing infrastructure systems at Shoals Marine Lab, they improve both the island’s future and their own sustainability engineering skill sets.
“I think it's really cool to see how the systems interact with each other and look at ways that we can make that more sustainable,” Hays said.