Monthly Archives: May 2021

Right whale #3720

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Right Whale #3720 with her calf

On March 18th Chris Paparo, the manager of Stony Brook University’s Marine Sciences Center reported a sighting of a mother right whale with her calf just 300 yards off an East Hampton ocean beach!  #3720, as she is called, had travelled from waters near Wassaw Island, Georgia, where she and her calf were last seen on Jan. 19th 2021, their final destination perhaps Cape Cod bay, or as far north as the gulf of St. Lawrence.

We all know that the right whale is a critically endangered species with less than 400 individuals still alive and perhaps less than 100 reproducing females.  Spotting calves with their mothers represents a glimmer of hope.

With plans to build an offshore South Fork Wind Farm 35 miles east of Montauk point and run a submarine cable coming ashore on a Wainscott beach, I could not help wonder how the developer (Ørsted) plans to safeguard these magnificent marine mammals.

Here is my lay person report.

  • Ørsted takes this very seriously.  I spoke with Sophie Hartfield Lewis, Ørsted Head of U.S. Permitting. Safeguarding whales are clearly dear to her heart. Together with Woods Hole Oceanographic Institution they are tackling issues like the correct distance between a source of submarine noise, such as pile driving, and a whale straying into the area. At what distance is there assured harm to the whale’s hearing (permanent or temporary)? At what distance do all drilling operations need to be halted? Currently that stands at 1 km depending on what marine species is involved and the type of noise emitted, including the noise frequency.  F.ex. frequencies above 200 mHz are deemed safe because whales don’t hear them or because they don’t have adverse reactions to them.
  • I also learned about techniques used to dampen noise.  (a) There is something called a ‘Big bubble curtain’ (BBC): it consists of a flexible tube fitted with special nozzle openings and installed on the seabed around the pile. Compressed air is forced through the nozzles producing a curtain of rising, expanding bubbles. These bubbles effectively attenuate noise by scattering sound on the air bubbles, absorbing sound, or reflecting sound off the air bubbles! (b) There is the Hydro-Sound Damper (HSD): it consists of a fisher net with different sized elements, laid out at various distances from each other, and encapsulating the pile. HSD elements can be foam plastic or gas-filled balloons. Noise is reduced as it crosses the HSD due to reflection and absorption. (c) There is the AdBm, Helmholz resonator: it consists of large arrays of Helmholtz resonators, or air filled containers with an opening on one side that can be set to vibrate at specific frequencies to absorb noise, deployed as a “fence” around pile driving activities.  Sophie told me that if operations were to start tomorrow, they would use BBC.
  • I spoke with Catherine Bowes of the National Wildlife  Foundation.  Key recommendations include: seasonal & temporal restrictions on pile driving; real-time monitoring of science-based exclusion zones; underwater noise limits; vessel speed restrictions; and commitments to pre, during & post-construction monitoring to ensure we learn as we go, in launching this new clean energy industry. This last point is essential for informing impact mitigation strategies along the coast. 

Sophie Hartfield Lewis directed me to an online pdf. Pages 100-166 directly concern mitigation strategies for the SFWF. It is titled “Protected Species Mitigation and Monitoring Plan South Fork Wind, LLC.“  I warn the reader: it gets pretty involved.

The world has seen an increasing and alarming number of extinctions in recent years. And that’s only the ones we know about. Ultimately, protecting threatened species protects us, the human species, because loss of biodiversity has health impacts among many other ill effects. Just google ’loss of biodiversity.’   Simultaneously, we are existentially threatened by climate change.  Thus, we have no choice. We need to save species like the right whale and we need offshore wind energy.

Win With Wind held a virtual seminar on

Offshore Wind Farms & Protection of Endangered Species

Q&A with 2 renowned experts:

Catherine Bowes,  Program Director, National Wildlife Federation

Sophie Hartfield Lewis, Head of Environment & Marine Affairs, Ørsted

Wednesday Jun 9, 2021, 4:00 – 5:30  PM

The seminar can be viewed in its entirety on YouTube:

Vertical turbines could be the future for wind farms

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Oxford Brookes University. “Vertical turbines could be the future for wind farms.” ScienceDaily. ScienceDaily, 27 April 2021. www.sciencedaily.com/releases/2021/04/210427085752.htm

Summary: The now-familiar sight of traditional propeller wind turbines could be replaced in the future with wind farms containing more compact and efficient vertical turbines. New research has found that the vertical turbine design is far more efficient than traditional turbines in large scale wind farms, and when set in pairs the vertical turbines increase each other’s performance by up to 15%.

The now-familiar sight of traditional propeller wind turbines could be replaced in the future with wind farms containing more compact and efficient vertical turbines. New research from Oxford Brookes University has found that the vertical turbine design is far more efficient than traditional turbines in large scale wind farms, and when set in pairs the vertical turbines increase each other’s performance by up to 15%.

A research team from the School of Engineering, Computing and Mathematics (ECM) at Oxford Brookes led by Professor Iakovos Tzanakis conducted an in-depth study using more than 11,500 hours of computer simulation to show that wind farms can perform more efficiently by substituting the traditional propeller type Horizontal Axis Wind Turbines (HAWTs), for compact Vertical Axis Wind Turbines (VAWTs).

Vertical turbines are more efficient than traditional windmill turbines

The research demonstrates for the first time at a realistic scale, the potential of large scale VAWTs to outcompete current HAWT wind farm turbines.

VAWTs spin around an axis vertical to the ground, and they exhibit the opposite behaviour of the well-known propeller design (HAWTs). The research found that VAWTs increase each other’s performance when arranged in grid formations. Positioning wind turbines to maximise outputs is critical to the design of wind farms.

Professor Tzanakis comments “This study evidences that the future of wind farms should be vertical. Vertical axis wind farm turbines can be designed to be much closer together, increasing their efficiency and ultimately lowering the prices of electricity. In the long run, VAWTs can help accelerate the green transition of our energy systems, so that more clean and sustainable energy comes from renewable sources.”

With the UK’s wind energy capacity expected to almost double by 2030, the findings are a stepping stone towards designing more efficient wind farms, understanding large scale wind energy harvesting techniques and ultimately improving the renewable energy technology to more quickly replace fossil fuels as sources of energy.

Cost effective way to meet wind power targets

According to the Global Wind Report 2021, the world needs to be installing wind power three times faster over the next decade, in order to meet net zero targets and avoid the worst impacts of climate change.

Lead author of the report and Bachelor of Engineering graduate Joachim Toftegaard Hansen commented: “Modern wind farms are one of the most efficient ways to generate green energy, however, they have one major flaw: as the wind approaches the front row of turbines, turbulence will be generated downstream. The turbulence is detrimental to the performance of the subsequent rows.

“In other words, the front row will convert about half the kinetic energy of the wind into electricity, whereas for the back row, that number is down to 25-30%. Each turbine costs more than £2 million/MW. As an engineer, it naturally occurred to me that there must be a more cost-effective way.”

The study is the first to comprehensively analyse many aspects of wind turbine performance, with regards to array angle, direction of rotation, turbine spacing, and number of rotors. It is also the first research to investigate whether the performance improvements hold true for three VAWT turbines set in a series.

Dr Mahak co-author of the article and Senior Lecturer in ECM comments: “The importance of using computational methods in understanding flow physics can’t be underestimated. These types of design and enhancement studies are a fraction of the cost compared to the huge experimental test facilities. This is particularly important at the initial design phase and is extremely useful for the industries trying to achieve maximum design efficiency and power output.” make a difference: sponsored opportunity

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Materials provided by Oxford Brookes University. Note: Content may be edited for style and length.

Journal Reference:

  1. Joachim Toftegaard Hansen, Mahak Mahak, Iakovos Tzanakis. Numerical modelling and optimization of vertical axis wind turbine pairs: A scale up approach. Renewable Energy, 2021; 171: 1371 DOI: 10.1016/j.renene.2021.03.001