trial

Vertical-axis wind turbines

February 19, 2025 By EarthWise Leave a Comment

Nearly all wind turbines in use today are horizonal axis wind turbines. They are a familiar sight with their three giant rotor blades spinning about an axis high above the ground attached to a nacelle containing the gearbox and generator.

A vertical-axis wind turbine has its rotor shaft transverse to the wind; that is, the shaft rises up from the ground and the gearbox and generator are located close to the ground.

This type of wind turbine does not need to be pointed into the wind, which eliminates the need for wind-sensing and orienting mechanisms. It is also considerably quieter in operation than horizontal axis wind turbines. Vertical-axis wind turbines have enjoyed minimal success to date because of a variety of problems including reliability issues and complications related to how they respond to changing wind conditions.

A next-generation vertical wind turbine is going on trial in Australia as part of a research collaboration between Flinders University in South Australia and the start-up company VAWT-X Energy. The 6KW prototype will be installed at a field site in Australia’s Fleurieu Peninsula.

According to the developers, the new turbine design will be as efficient, or even more efficient, as existing horizontal turbines and will be able to thrive across diverse environments including being part of urban infrastructure where their relative quiet is a real advantage. Such turbines would be more accessible for applications like off-grid power and sustainable energy solutions for small businesses and farms. The developers claim the technology can also be scaled up for large-scale windfarms.

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Progress with new-look wind turbine

Photo courtesy of VAWT-X Energy.

Earth Wise is a production of WAMC Northeast Public Radio

Self-Deicing Roads | Earth Wise

March 23, 2023 By EarthWise Leave a Comment

Driving on snowy or icy roads can be pretty dangerous. That is why roads are salted or coated with sand to provide traction in icy weather. But excessive use of these substances is bad for the environment and sometimes a storm will blow in before the roads can be coated.

In a paper published in the American Chemical Society Journal ACS Omega, researchers in China describe a method of adding microcapsules filled with a chloride-free salt mixture to the asphalt with which roads are paved. The idea is to provide the road itself with long-term snow melting capabilities.

The researchers prepared a sodium-acetate salt and combined it with a surfactant, silicon dioxide, sodium bicarbonate, and blast furnace slag, which is a waste product from power plants. The substances were reduced to a fine powder and then coated with a polymer solution to form tiny microcapsules. The microcapsules were then used to replace some of the standard mineral filler in asphalt.

Lab experiments showed that the special additive lowered the freezing point of water on the asphalt to -6 degrees Fahrenheit. The researchers estimated that a 2-inch-thick layer of the anti-icing asphalt would be effective at melting snow for seven or eight years. A real-world pilot test of the coating on a highway offramp showed that it melted snow that fell on the road whereas an uncoated road required snow removal operations.

According to the researchers, given the cost of materials used for the coating and its potential useful lifetime, it could be a practical and economic enhancement for wintertime snow and ice removal. Maybe we’ll someday have roads that can fairly often deice themselves.

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Keeping drivers safe with a road that can melt snow, ice on its own

Photo, posted April 8, 2007, courtesy of the Oregon Department of Transportation via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A Promising Malaria Vaccine | Earth Wise

June 23, 2021 By EarthWise Leave a Comment

Malaria is a parasitic disease transmitted through the bite of female Anopheles mosquitoes. Although the disease is both preventable and treatable, an estimated 435,000 people die of it each year, with the majority being children younger than five. Over 90% of all malaria cases and deaths occur in Africa.

The battle against malaria has mostly centered around the use of bed nets, insecticide spraying and antimalarial drugs. To date, there has not been an effective malaria vaccine available.

That may finally be changing. The first vaccinations have begun in Mali in a phase III trial of a malaria vaccine developed by the University of Oxford. The Oxford vaccine showed an efficacy of 77% over 12 months in a phase IIb trial and the hope is that the phase III trial will lead to the licensing of the vaccine in 2023.

Oxford is partnering with the Serum Institute of India for the manufacturing of the vaccine in order to be able to produce high volumes of low-cost vaccine and provide access to countries where it is required the most. The Serum Institute has committed to the production of more than 200 million doses per year once the vaccine is licensed for use, which will be an adequate supply for children most at risk of malaria in sub-Saharan Africa.

The World Health Organization Malaria Vaccine Technology Roadmap has a goal of a malaria vaccine with at least 75% efficacy. Such a vaccine is needed in order to reach the WHO’s goal of reducing malaria deaths by at least 90% by 2030.

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Promising malaria vaccine enters final stage of clinical testing in West Africa

Photo, posted June 9, 2018, courtesy of Mario Yordanov via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.