Are Vertical Axis Turbines the Future of Offshore Wind Power?

As turbines scale ever bigger, new work on old designs might present some advantages.

2 min read
Are Vertical Axis Turbines the Future of Offshore Wind Power?

Vertical axis wind turbines, or VAWTs, have been around for many years. Generally they are considered less effective than the standard horizontal axis turbines that increasingly dot the landscape, but they do have their advantages. And as the U.S. pushes ever harder to join the offshore wind power party, there is renewed interest in VAWT designs for offshore use.

Sandia National Laboratories in Albuquerque, New Mexico, part of the Department of Energy (DOE), is working under a DOE-funded program to re-evaluate VAWT designs for offshore use. They say that the vertical turbines have several advantages over standard windmills. These include a lower center of gravity, reduced complexity of design, and better scalability to very large sizes. 

That last characteristic is crucial, and unique to offshore wind power. Companies have been rapidly scaling up offshore turbine sizes, reaching mammoth 7-megawatt sizes in recent years. According to a Sandia press release:

Large offshore VAWT blades in excess of 300 meters will cost more to produce than blades for onshore wind turbines. But as the machines and their foundations get bigger—closer to the 10–20 megawatt (MW) scale—turbines and rotors become a much smaller percentage of the overall system cost for offshore turbines, so other benefits of the VAWT architecture could more than offset the increased rotor cost.

Still, making enormous VAWT blades is difficult. The blades are significantly curved, which becomes more and more of a manufacturing challenge as they grow in size. There is also a difficulty involved with "cyclic loading" on the drivetrain of a VAWT: the torque on the blade differs as it rotates, based on whether the blade is in the upwind or downwind position. Sandia will evaluate new rotor designs that help balance out these torque differences. The end result of this project will hopefully be some new turbines capable of filling what will theoretically be a burgeoning U.S. offshore wind market.

One of these days, offshore wind power is finally going to make it to U.S. waters; it will be nice to have a variety of high-power, high-efficiency options for turbines when that day arrives.

Image: Sandia National Laboratories

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How to Prevent Blackouts by Packetizing the Power Grid

The rules of the Internet can also balance electricity supply and demand

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How to Prevent Blackouts by Packetizing the Power Grid
Dan Page

Bad things happen when demand outstrips supply. We learned that lesson too well at the start of the pandemic, when demand for toilet paper, disinfecting wipes, masks, and ventilators outstripped the available supply. Today, chip shortages continue to disrupt the consumer electronics, automobile, and other sectors. Clearly, balancing the supply and demand of goods is critical for a stable, normal, functional society.

That need for balance is true of electric power grids, too. We got a heartrending reminder of this fact in February 2021, when Texas experienced an unprecedented and deadly winter freeze. Spiking demand for electric heat collided with supply problems created by frozen natural-gas equipment and below-average wind-power production. The resulting imbalance left more than 2 million households without power for days, caused at least 210 deaths, and led to economic losses of up to US $130 billion.

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