By: Neil Markee
Editor in Chief-Purchasing Link

Here on Long Island, and I suspect just about anywhere, few people want to sit on their decks or docks and watch a group of towering stately, wind turbines slowly rotating, as they generate the expensive, but clean, electrical power from renewable sources that seem to be the holy grail of future  power-supply planning. “Not on my horizon” is likely to be what the protest signs will read.  People just don’t want to be locked into looking at those tall, slender, efficient-looking, engineering marvels—no matter how beneficial they are. You may recall the big-name congressional dust up a few years ago when a wind farm was proposed for the sound off Nantucket and within sight from land. Currently, similarly contentious sites are under consideration off the south shore and eastern tip of Long Island.  Building them far enough offshore, to be over the horizon and invisible from shore, might be a solution.  But constructing traditional sea-floor-based towers in very deep water would likely be expensive and challenging. 

And there are other serious objections.  Commercial fishermen seek bottom structure, banks and other relatively shallow areas to spread their nets, drag their trawls, and set their pots to catch the seafood that helps feed the nation and provides the income to support the families involved with the industry. Reasonably, they do not want scores of towers planted on what they see as their fishing grounds. They are certain, and entitled, to employ every political and legal means at their disposal to block the construction. Think, long delay!

There are legitimate complaints from the shipping industry as well.  The sea lanes that approach major ports typically pass over the same near-shore bottom used by fishermen and targeted by wind power entrepreneurs.  Every obstruction is one more hazard that must be avoided on a stormy or foggy night. Given inevitable human error and electronic and mechanical failure, we probably should anticipate collisions involving huge container ships or tankers hitting towers sooner or later. The essence of seaborne containerized or bulk commerce is speed, rapid turn-around, and schedule keeping. Profit margins are thin in the very competitive industries and anything that causes delay is a serious economic problem. Shippers would likely opt to go to less-encumbered ports.  A possible answer to the aesthetic, commercial and safety issues might be to move the towers further offshore and away from sea lanes approaching ports. But as the water depth increases rapidly with distance off shore, soon the cost of building fixed towers very far offshore becomes prohibitive or beyond reasonable engineering capabilities.

That’s the downside, but there may be viable solutions to many of these problems. The oil/gas industry has long addressed deep-water drilling problems by building moored floating platforms not resting on the sea bottom.  Drilling technology allows several wells to be operated from one platform.  The oil or gas extracted is delivered ashore to refineries or pipeline terminals via underwater pipelines or tankers.  Floating rigs are self-contained and the scores of workers who operate the complex machinery involved nonstop live on board and rotated back ashore regularly. Typically these people are moved by helicopter.  Food and any needed supplies are delivered by specialized small ships.

Why couldn’t wind turbine towers be built on similarly sized platforms?  They could, although the cost would be prohibitive.  Oil/gas wells can be clustered in a relatively small area of the sea-floor area and served by one large-anchored platform, but wind turbines must be spread out because of the large area swept by their rotating blades. And they have no need for a large platform as their product, electricity, doesn’t require processing before being transported. In effect, each wind turbine only needs its own small stable uninhabited floating platform.  According to an article in the 9/30/16 New York Times, The University of Maine is working on what may be a solution.  The article titled “Wind Farms See Promise in Platforms That Float” discussed a pilot project managed by the university. The project is partially financed by grants of $22.7 million from the energy department and another $39.9 million may be in the offing for completion.  “Dr. Dagher (Habib Joseph Dagher director of the university’s Advanced Structures and Composites Center) said that if all went well, his team could have two full-scale turbines pumping electricity into the Maine grid in 2019 and larger commercial farms starting construction in the Gulf of Maine by the mid-2020s.”

In addition to the University of Maine project, “Statoil, the Norwegian oil and gas giant, is already developing what could become the first commercial-scale floating wind farm, off the coast of Scotland.” Other organizations involved with floating wind farms mentioned in the article include Seattle based   Trident Winds and Emeryville California based Principle Power.”

“Various types of floating wind platforms are in the works, but two are closest to commercial availability. Statoil’s design, known as Hywind, attaches the turbine to a special buoy that uses a steel cylinder filled with water and rocks as ballast—a floating structure that extends more than 300 feet beneath the water’s surface.  Principle Power’s foundation, known as the WindFloat, sets the turbine atop one of three columns that are partly underwater and connected with a triangular frame.”  The University of Maine’s prototype, part of a demonstration project called Aqua Ventus, is similar to the WindFloat. But the Aqua Ventus fixes the turbine on a floating, central, concrete pier attached by spokes to three others, a design that Dr.Dagher said would make it cheaper to produce.”     

The people involved recognize that cost is an obstacle.  Floating wind farms are currently more expensive to build than the land-based variety and logic suggests that they will be more expensive to operate given the servicing difficulties involved and the hostile salt-water environment. Some participants however predict construction costs will come down as expertise matures. However, costs could well balloon as additional challenges are recognized.  Wind power ashore is more expensive than cheaper conventional sources and I think it’s probably reasonable to assume that power from floating farms will be even more expensive. There was no mention of the cost of leasing a sea-floor site from the federal government but the cost of leasing federal land in the west is becoming an issue.    

Currently, land- or sea-based wind power is not a viable, large-scale alternative to fossil fuels. The search for low-cost renewable sources of clean power continues. However, this approach potentially offers a means to generate offshore wind power in areas where land-based or fixed-to-the-sea floor wind turbine towers are not viable for political, environmental or other reasons.  Moored approaches cause less damage to the ocean floor than fixed tower bases because of their smaller foot print. And there is another plus, “More than half of the United States’ potential capturable off-shore wind capacity – more than what the entire nation can now produce—is in deeper waters,” said Jose Zayas, who directs the Wind Energy Technologies Office at the federal Department of Energy.

What will it take to meaningfully reduce the planet’s dependence on burning gas, oil and coal to produce electrical energy? An article by Amy Harder and Cassandra Sweet in the October 27, 2016 Wall Street Journal provided a list of the current significant sources of power. There was no mention of oil.  Perhaps its contribution was bundled with Gas or included in “other.” The chart was sourced from the Department of Energy.  In any case, it seems obvious that weaning the nation and the planet off the first two sources will require many decades, given the magnitude of the challenge and our net progress since climate change became an issue. 

For a while, nuclear power was seen as the answer to reducing carbon in the atmosphere while producing clean cheap power.  And nuclear may eventually be a major part of the solution, if we can find answers to the waste disposal and political issues.  Both wind and solar require the availability of basically instantaneous back-up, should the sun be obscured or the wind die down or become too strong. Perhaps this is a role non-carbon producing nuclear might play. Because of the required backup, neither wind nor solar are completely green power sources, if the backup power is produced by burning oil, gas or coal.

While we are waiting for the major breakthroughs needed, wind, solar, thermal and other sources of clean power are being investigated.  This article is about sea-based wind power generation. Alone, I doubt that floating or other wind turbines, as we know them, can be the answer, because of the cost and space required. But looking seaward and adding power from wave action, tides and ocean currents might add up to a significant source of reliable power.   

Something big is happening at the University of Maine.  What’s happening on your campus?