Wind turbines across the globe are being made taller to capture more energy from the stronger winds that blow at greater heights.
But it’s not easy, or sometimes even economically feasible, to build taller towers, with shipping constraints on tower diameters and the expense involved in construction.
Now Keystone Tower Systems — co-founded by Eric Smith ’01, SM ’07, Rosalind Takata ’00, SM ’06, and Alexander Slocum, the Pappalardo Professor of Mechanical Engineering at MIT — is developing a novel system that adapts a traditional pipe-making technology to churn out wind turbines on location, at wind farms, making taller towers more economically feasible.
Keystone’s system is a modification of spiral welding, a process that’s been used for decades to make large pipes. In that process, steel sheets are fed into one side of a machine, where they’re continuously rolled into a spiral, while their edges are welded together to create a pipe — sort of like a massive paper-towel tube.
Developed by Smith, Takata, and Slocum — along with a team of engineers, including Daniel Bridgers SM ’12 and Dan Ainge ’12 — Keystone’s system allows the steel rolls to be tapered and made of varying thickness, to create a conical tower. The system is highly automated — using about one-tenth the labor of traditional construction — and uses steel to make the whole tower, instead of concrete. “This makes it much more cost-effective to build much taller towers,” says Smith, Keystone’s CEO.
With Keystone’s onsite fabrication, Smith says, manufactures can make towers that reach more than 400 feet. Wind that high can be up to 50 percent stronger and, moreover, isn’t blocked by trees, Smith says. A 460-foot tower, for instance, could increase energy capture by 10 to 50 percent, compared with today’s more common 260-foot towers.
“That’s site-dependent,” Smith adds. “If you go somewhere in the Midwest where there’s open plains, but no trees, you’re going to see a benefit, but it might not be a large benefit. But if you go somewhere with tree cover, like in Maine — because the trees slow down the wind near the ground — you can see a 50 percent increase in energy capture for the same wind turbine.”
Image Credit: MIT
Wave energy – recently characterized by one leading academic in the field as being “in kindergarten” compared to fossil fuels – isn’t about to graduate to the big time, but the effort to build a meaningful industry in the U.S. could advance several grades in the next few years. Not one, not two, but at least three full-scale wave energy converters, all intended to produce significant grid power when deployed in arrays, are now in line to be tested in Hawaii.
Columbia Power Technologies told Breaking Energy that it had signed a $3 million contract with the U.S. Navy that will support deployment of the company’s StingRAY device offshore from Marine Corps Base Hawaii Kaneohe Bay. Just last week the U.S. Department of Energy said it had selected Northwest Energy Innovations and Ocean Energy to receive a total of $10 million to deploy devices at the same test site, on the windward side of Oahu.
The Wave Energy Test Site in Hawaii will feature two grid-connected berths, and it wasn’t clear when exactly the three devices that have landed spots would go in the water. Industry sources said, too, that there could actually be a fourth device bound for Hawaii, through another Navy contract, but that remained to be confirmed. For his part, Columbia Power CEO Reenst Lesemann said his company expected to begin its year-long Hawaii trial in the second half of 2016.
Hydropower has long provided a flexible, low-cost, and renewable source of power for the United States—since the 1800s, in fact. Even today, in fact, hydropower accounted for roughly half of the nation’s renewable-generated electricity in 2013. The Energy Department, in collaboration with the national laboratories and industry, is working to advance hydropower technologies by making them more efficient and environmental friendly.
Over the past 15 years, the Pacific Northwest National Laboratory (PNNL) has developed and improved a small device called the Sensor Fish that measures the physical forces fish experience as they pass through hydroelectric facilities such as dam turbines and spillways.
The Sensor Fish provides researchers with quick, reliable feedback on changes in pressure, acceleration, strain, turbulence, and other forces as the neutrally-buoyant device moves through hydro facilities—providing a close picture of what the fish would experience.
The Sensor Fish, funded in part by the Energy Department’s Water Power Program, represents a big breakthrough for biologists and engineers, who previously relied largely on live fish tests or computer models to study spillway and turbine passage environments. Researchers can now use the Sensor Fish in combination with other available methods to collect better data and help improve the design of more fish-friendly turbines and hydropower projects, improving the survival rate of fish populations and lessening the chance of individual fish injuries.
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Boosting household energy access has a minimal direct impact on climate change, according to a new paper that argues ending poverty should be the top short-term priority for poor countries.
The study published in the journal Nature Climate Change is among the first empirical studies to measure how a vast improvement in electrification—in this case, in India—contributed to greenhouse gas emissions levels.
The findings could create a snarl in the efforts of environmental groups who say renewable energy should be the key, if not only, tool to bringing modern electricity services to the 1.5 billion people worldwide living in darkness.
With few quantified studies available to see just how high emissions grow when poor communities gain electricity, author Shonali Pachauri (a senior research scholar at the International Institute for Applied Systems Analysis in Austria ) said she set out to find hard numbers. She did so in India, where more than 400 million people still live without electricity.
Pachauri found two key data sets were available: national numbers showing how much electricity had improved and nationally representative household surveys going back to 1983 that included information about whether the family had access to energy and, if so, how much electricity each household consumes.
Crunching those numbers, she found that improvements in household energy access bumped up national emissions just 3.4 percent. That, she said, is largely because even as rates of electrification rose, consumption remained generally low.
“There is certainly a rich minority that is using a lot of electricity, but for the majority of largely poor households, they still consume very, very low amounts of electricity,” Pachauri said.
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Up to one fifth of the world’s electricity supply could come from wind turbines by 2030, according to a new report released this week by Greenpeace and the Global Wind Energy Council (GWEC). That would be an increase of 530 percent compared to the end of last year.
The report says the coming global boom in wind power will be driven largely by China’s rebounding wind energy market—and a continued trend of high levels of Chinese green energy investment—as well as by steady growth in the United States and new large-scale projects in Mexico, Brazil, and South Africa.
The report, called the “Global Wind Energy Outlook,” explains how wind energy could provide 2,000 gigawatts of electricity by 2030, which would account for 17 to 19 percent of global electricity. And by 2050, wind’s share of the electricity market could reach 30 percent. That’s a huge jump from the end of 2013, when wind provided around 3 percent of electricity worldwide.
Expanding the notion of corporate benefits beyond discounted health club memberships and low insurance rates, a group of major companies is set to offer employees access to cheaper solar systems for the home.
Under an arrangement announced Wednesday, employees of the companies — Cisco Systems, 3M, Kimberly-Clark and National Geographic — will be able to buy or lease solar systems for their homes at rates substantially lower than the national average, executives said. The program, offered through Geostellar, an online marketer of solar systems, will be available to more than 100,000 employees and will include options for their friends and families in the United States and parts of Canada.
Conceived at the World Wildlife Fund, the program, called the Solar Community Initiative, aims to use the bulk buying power of employees to allow for discounts on home systems.
The program’s expansion is a reflection of the shrinking gulf between camps that were once considered mutually exclusive: environmental advocacy organizations and mainstream corporate America.