Thursday, November 29, 2012

World's largest wind turbine installed in Denmark

The first commercial offshore wind turbine that Siemens created 30 years ago had 5-meter long blades and produced a paltry 30kW. A lot can change over three decades.The company's newest offshore model isn't just the biggest in the sea; it's the biggest anywhere.

Known by an alphanumeric jumble (STW-6.0-154), the turbine produces a whopping 6MW of power—nearly 25,000 times as much as Siemen's original mode—and utilizes a trio of 75-meter turbine blades—the world's largest—for a rotor diameter of 154 meters—equal to the wingspan of an Airbus 380 and a humongous 18600 meter-square sweep area. In all, each turbine can produce 25 million kilowatt hours of energy. That's enough to power 6,000 homes.

Siemens developed the 6 MW turbine exclusively for use at sea, which presents an entirely different set of problems and opportunities than on land. Offshore turbines need to be lighter, more robust, and more reliable given their distance from nearby mechanics. That's why Siemens replaced two-thirds of the traditional drive train—the main shaft, gearbox and high-speed generator—with its proprietary Direct Drive system that instead uses a low speed generator connected directly to the low-speed shaft. If the part isn't there to break, you won't need to send someone out to fix it.

What's more, the Direct Drive system also frees up a significant amount of space in the turbine's nacelle (the main body housing), enough to fit a small crane for lifting heavy generator components and a coffee machine for lifting servicemen. This system also makes the STW-6.0-154 the lightest turbine in its class, with a 200 ton nacelle and a 350 ton total masthead weight. "At the same time, the turbine delivers an increased energy yield and offers greater profitability over its life cycle," Henrik Stiesdal, CTO of the Wind Power Division within the Siemens Energy Sector, said in a press release.

Part of this weight savings comes from the turbine's IntegralBlade technology which generates a 20-percent savings over conventional production methods. The 6 MW turbine is capable of using either a specially built 154 meter rotor for maximum power generation or a slightly shorter 120 meter long blade, the same that the 3.6 MW model uses, for areas near airports and flight paths that have a 150 meter tip-height restriction.

Wednesday, November 28, 2012

Nanotube Hybrid Makes Single-Surface Material for Energy Storage

A seamless graphene/nanotube hybrid created at Rice University may be the best electrode interface material possible for many energy storage and electronics applications.

Led by Rice chemist James Tour, researchers have successfully grown forests of carbon nanotubes that rise quickly from sheets of graphene to astounding lengths of up to 120 microns, according to a paper published November 27 by Nature Communications. A house on an average plot with the same aspect ratio would rise into space.

That translates into a massive amount of surface area, the key factor in making things like energy-storing supercapacitors.

The Rice hybrid combines two-dimensional graphene, which is a sheet of carbon one atom thick, and nanotubes into a seamless three-dimensional structure. The bonds between them are covalent, which means adjacent carbon atoms share electrons in a highly stable configuration. The nanotubes aren't merely sitting on the graphene sheet; they become a part of it.

"Many people have tried to attach nanotubes to a metal electrode and it's never gone very well because they get a little electronic barrier right at the interface," Tour said. "By growing graphene on metal (in this case copper) and then growing nanotubes from the graphene, the electrical contact between the nanotubes and the metal electrode is ohmic. That means electrons see no difference, because it's all one seamless material.

"This gives us, effectively, a very high surface area of more than 2,000 square meters per gram of material. It's a huge number," said Tour, Rice's T.T. and W.F. Chao Chair in Chemistry as well as a professor of mechanical engineering and materials science and of computer science and a co-author with former postdoctoral researcher and lead author Yu Zhu, now an assistant professor at the University of Akron.

Tour said proof of the material's hybrid nature lies in the seven-membered rings at the transition from graphene to nanotube, a structure predicted by theory for such a material and now confirmed through electron microscope images with subnanometer resolution.

Carbon has no peer as a conductive material in such a thin and robust form, especially in the form of graphene or certain types of nanotubes. Combining the two appears to offer great potential for electronic components like fast supercapacitors that, because of the massive surface area, may hold a great deal of energy in a tiny package.

Rice chemist Robert Hauge and his team made the first steps toward such a hybrid over the past decade. Hauge, a distinguished faculty fellow in chemistry at Rice and co-author of the new work, discovered a way to make densely packed carpets of nanotubes on a carbon substrate by suspending catalyst-laced flakes in a furnace. When heated, the catalyst built carbon nanotubes like skyscrapers, starting at the substrate and working their way up. In the process, they lifted the aluminum oxide buffer into the air. The whole thing looked like a kite with many strings and was dubbed an odako, like the giant Japanese kites.

In the new work, the team grew a specialized odako that retained the iron catalyst and aluminum oxide buffer but put them on top of a layer of graphene grown separately on a copper substrate. The copper stayed to serve as an excellent current collector for the three-dimensional hybrids that were grown within minutes to controllable lengths of up to 120 microns.

Electron microscope images showed the one-, two- and three-walled nanotubes firmly embedded in the graphene, and electrical testing showed no resistance to the flow of current at the junction.

"The performance we see in this study is as good as the best carbon-based supercapacitors that have ever been made," Tour said. "We're not really a supercapacitor lab, and still we were able to match the performance because of the quality of the electrode. It's really remarkable, and it all harkens back to that unique interface."

Monday, November 19, 2012

Tools of the trade: waxy carbon tracing paper

Waxy carbon transfer paper is a fantastic tool that’s really difficult to find. I’ve wanted to be able to offer this tool to you for a couple of years now, and I’m so pleased that I was finally able to track down a source for it. (Believe me, it took some significant sleuthing to locate a supply!) We now have it available by the sheet in both blue and yellow colors.

It’s a shame that it’s so hard to find because it’s very useful. Waxy carbon paper is great for two purposes: tracing patterns and transferring markings onto fabric. It can be used on paper and on fabric. I like the blue and yellow carbon paper for almost everything, and these two colors serve different purposes. I’ll explain how and when I use them.

I use this carbon paper for making muslins so I can see the seam lines, dart markings, and notches as I’m making adjustments to a fit muslin. I talked about this in the muslin tutorial, if you’re interested in learning more. I mostly use blue carbon for muslins because the carbon lines are extremely visible on the fabric, but if I’m making a correction and want to distinguish my new markings from the original (blue) markings, I’ll switch to the yellow so I don’t confuse them.

Waxy carbon can also be useful for transferring markings to your fabric when you’re sewing. The lines it makes are very accurate and quick to transfer with the carbon and tracing wheel, so they’re great for transferring darts and other markings.

There are two things to keep in mind if you use waxy carbon on fashion fabric. First, waxy carbon markings are often permanent (they can sometimes be removed by a dry cleaner, but don’t count on it!), so use the lightest color that will show on the wrong side of your fabric and mark only the wrong side of your fabric. You don’t want those markings to show when you’re finished! I almost always use the yellow carbon on fabrics other than a fit muslin because the yellow is less messy and less likely to show from the right side of the finished garment.

The other thing to keep in mind is the thickness of the fabric itself. Again, because the markings are permanent there is always a possibility that they will be visible from the right side of the fabric if your fabric is thin or sheer. So test the carbon on a scrap of fabric if you’re not sure whether it’s safe for the fabric you’ve chosen. For many fabrics it will be fine, but it’s always a good idea to check first, just to be sure.

Thursday, November 15, 2012

Solar Jobs Figures Show Smart Policy Works

The Solar Energy Industries Association, or SEIA, today responded to the full results from The Solar Foundation’s (TSF) third annual National Solar Jobs Census, which details subsector job figures for the U.S. solar energy industry. The report shows the continued growth in U.S. solar jobs is led by system installers, sales and distribution, and other support services.

Top line results released Nov. 2, 2012 found that the industry has grown to support 119,016 U.S. jobs across all 50 states. TSF’s 2012 census shows 13.2% growth over 2011. Companies that install solar now employ 57,177 Americans, a 17.5% increase over 2011 figures. Sales and distribution jobs experienced a 23.1% increase, now employing 16,005 Americans.

“These results are clear – the U.S. solar industry is strong and growing, and we are putting Americans back to work,” says Rhone Resch, president and CEO of SEIA. “As the cost of solar continues to come down, more companies and homeowners are turning to solar for their electricity and hot water. This increase in demand for solar energy is creating economic opportunities throughout the U.S. Going forward, we expect a record year for new solar projects and corresponding job growth in 2013. This should serve as a signal to policymakers that clean energy policies are doing what they were intended to do – grow our economy.”

“The National Solar Jobs Census 2012 illustrates that the solar industry, as a whole, is a dependable job creator and that solar employers are confident about growth in 2013,” says Andrea Luecke, executive director of TSF. “The growth by installers, especially at larger firms, signals that this subsector is heading toward a period of consolidation and maturation on par with other successful industries at this stage of the growth curve.”

Still, not every subsector exhibited strong job growth. Manufacturing jobs decreased from 37,941 jobs in 2011 to 29,742 jobs today.

“While manufacturer jobs losses are unfortunate, this is a sign of a maturing and highly-competitive global industry. We’ve seen this consolidation trend in other industries, and we’ll see it again. Still, more than 1,000 solar manufacturers operate in the U.S., and with strong demand expected in 2013, they are positioned to make a rebound. This makes it all the more important to continue smart federal and state solar policies that drive private sector investment,” Resch says

Solar employers in all subsectors expressed optimism in their census responses about future job growth. They expect to grow by 17.2% over the next 12 months, representing an addition of 20,000 new jobs for Americans.

The Solar Foundation and BW Research used an improved version of the Solar Energy Industries Association’s National Solar Database to reach more employers. As a result, the solar employment figure for 2011 was revised upwards from 100,237 to 105,145. As in previous years, the survey examined employment throughout the solar value chain, including installation, sales and distribution, manufacturing, and other relevant subsectors and includes job numbers and growth rates. The census counts only direct jobs. The figures in the report were derived from data collected from more than 1,000 solar company survey respondents, yielding a low overall margin of error of +/-1.5%. The National Solar Jobs Census 2012 was conducted by The Solar Foundation and BW Research with technical assistance from Cornell University.

Tuesday, November 13, 2012

Inhabitat's Week in Green: Dyson Spheres, bladeless wind turbines and airless bike tires

Over at Inhabitat, the election hangover is finally starting to wear off, and we've been looking forward to see what President Obama's re-election could mean for clean tech and renewable energy. The first bit of good news came on election night, when Obama called for action on climate change. That's all well and good, but what does it actually mean? For starters, it could mean the EPA enforcing stricter regulations. But the thing that most people in the renewable energy sector will be watching is whether the wind energy tax credit is renewed before it expires at the end of the year.

Even if the federal tax credit for wind energy isn't renewed, there's still hope for renewable energy. Scientists at Penn State just kicked off a two-year search for massive alien solar power stations known as Dyson Spheres. If they find one, maybe extraterrestrials could give us some tips on intergalactic solar technology. Here on Earth, Natcore Technology has created the world's first commercially viable absolute black silicon cell, which can make virtually 100 percent of received sunlight available for conversion into electricity. Speaking of solar efficiency, this week solar manufacturer Amonix announced that its concentrated photovoltaic technology has set a new efficiency record with a conversion rate of 33.5 percent. In other solar news, the Westmill Solar Cooperative launched the world's largest community-owned solar project in the UK, a group of African teenagers developed a pee-powered energy generator and Tunisian company Saphon Energy unveiled a new bladeless, bird-friendly wind turbine.

From bionic limbs to airless bike tires, we've been tracking some pretty incredible new technological innovations. RSL Steeper unveiled the bebionic 3, an amazing new prosthetic hand that is strong enough to hold 99 pounds and sensitive enough to write with a pen. In an unrelated story, 31-year-old Zac Vawter, who lost his leg in a motorcycle accident, climbed 103 floors of Chicago's Willis Tower wearing a bionic leg. BriTek recently unveiled its amazing new Energy Return Wheel, which is an airless bike tire that can never go flat. We also showcased several innovations from the intersection of fashion and technology -- a light-up Twitter dress, a pair of "Social Denim" jeans that let you update your Facebook status on the fly and a brilliant "Rocking Knit" chair that uses kinetic energy generated from the chair's gliding motion to knit a winter hat while you sit.

In the week since Hurricane Sandy crashed into the East Coast, Inhabitat has been continuing its coverage of the recovery effort. Greenpeace's Rolling Sunlight mobile solar power array has been touring the streets of the Rockaways this week, enabling residents to charge their phones and other devices. We also covered several off-grid devices that we'd like to have in the event of another storm of Sandy's magnitude -- Nokero's compact SunRay Pro solar charger, Berkey's super-versatile and effective water filter and Eton's hand-crank cellphone charger. And this week we caught up with photographer Iwan Baan, who took the iconic photo of a darkened lower Manhattan that graced the cover of New York magazine.

With the winter bearing down, we've put together a series of guides explaining how to winter-proof your home and how to save money with a programmable thermostat. And looking forward to the holidays (sorry, but yes, they're coming up), we've put together a comprehensive guide to greening your holiday decor.
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Thursday, November 8, 2012

Wind Power's Operating and Maintenance Costs Plunge

If this keeps up, the wind power industry might not need the embattled production tax credit for very much longer. Which, come to think of it, is the stated point of the subsidy: to provide support for the industry while it evolves to a lower cost structure and ultimately becomes self-sufficient.

The new evidence that this hoped-for storyline is unfolding comes from Bloomberg New Energy Finance, which reports that operation and maintenance costs for the wind energy sector worldwide fell 38 percent from 2008 to 2011, or about 11 percent per year.

Wind power has done much to improve its competitiveness against gas-fired and coal-fired generation in recent years, via lower-cost, more technically advanced turbines, and more sophisticated siting and management of wind farms,” BNEF’s Michael Liebreich said in a statement. “This new O&M Price Index shows that servicing wind farms at the operating stage is also becoming much more cost-efficient.”

These cost figures aren’t based on some kind of theoretical estimate -- BNEF used actual contractual data submitted to it by 38 wind power companies around the world. “The data have covered 104 confidential and undisclosed O&M contracts, totaling 5.3 gigawatts of contracted capacity, in more than 24 markets,” BNEF said. “In all cases, the service providers are the turbine manufacturers, with a main focus in Europe and the Americas.”

Bloomberg listed six main points from its O&M research (quoting here):

    Average prices for full-service O&M contracts fell to EUR 19,200 ($24,700) per megawatt per year in 2012 -- a 38 percent decrease since 2008. The decline in O&M prices was driven by increased competition, as turbine manufacturers vie for service contracts, as well as by improved service performance of the underlying turbines.
    Average contract duration has risen from 4.5 years in 2008 to 6.9 years in 2012, as manufacturers attempt to lock in longer-term agreements.
    Average availability guarantees in the contract sample reached 96.9 percent, with any upside beyond that generally shared between the developer and service provider. Guarantees on actual energy production are also becoming more commonplace.
    Markets in Eastern Europe and the U.K. had the highest pricing for full-service offerings. This may be due to higher labor costs and/or a limited local supply chain. The U.S. displayed the most competitive pricing of all markets.
    Pricing between manufacturers has been fairly similar in 2008-2012, with the exception of one manufacturer, German company Enercon. Its prices for full-service contracts were nearly 20 percent lower than the market average throughout the whole period.
    Index participants expect O&M pricing be fairly stable at least until 2015. They regard Enercon, Siemens and Vestas as the best service providers in the industry in terms of promptness and quality of service for scheduled and unscheduled works.

Monday, November 5, 2012

Nebraska What is Happening To Wind Energy Projects

According to Thursdays’ report, Nebraska is missing a great opportunity for job creation to the state economy. This followed equally with cleaner form of energy, and is thereby trailing its neighbours in wind-energy development, like Iowa, South Dakota, Wyoming, Colorado and Kansas.

Nebraska is in a good position to use wind as a renewable-energy resource, claimed a group of lawmakers and environmental advocates as they revealed the report.

According to the report which was commissioned on behalf of the Nebraska Sierra Club, ranking as the fourth-best wind-producing state in the nation, yet Nebraska is 25th in the amount it could produce with the equipment currently installed.

Lawmakers and environmental advocates said they planned to pitch wind-energy to local public power districts that regulate energy usage throughout the state. Ken Winston, the group’s policy advocate says that during University of Nebraska football games, the Nebraska Sierra Club is preparing to air a series of clean-energy radio ads.

State Sen. Ken Haar, of Malcolm says that in spite of having enormous potential, they were not using that potential and that by investing in renewable energy and energy efficiency will ultimately lower costs for Nebraskans.

Due to Nebraska’s reliance on coal, money is being pumped into Wyoming through an excise tax that helps offset the cost of property taxes in that state.

Two days after the dedication of a new wind farm near Broken Bow, the report was released. Over its 25-year lifespan, the $145 million project is anticipated to produce $540,000 a year in lease royalties for landowners.

Next week in Lincoln, renewable-energy advocates are scheduled to gather for the state’s fifth annual wind-energy conference.

Over the next two decades, expanding wind energy could save Nebraska consumers a combined $3.8 billion, says an Arizona-based energy economist, Skip Laitner, who authored the report. Nearly 14,000 new jobs in Nebraska could be created with wind energy expansion over the next two decades, he adds.

Consumption of energy will pour 44,000 tons of nitrogen dioxide and 71,000 tons of sulfur dioxide into the atmosphere, and Nebraskans will spend as estimated $2.7 billion this year to meet energy needs. Laitner also says that about $700 million is added to the nation’s annual health care costs caused by these emissions which create “profound health problems.”

Laitner says that when we stack up that kind of perspective and then step back and ask a question which is, could we do it better. The numbers clearly indicate that they can.

Just like ethanol, wind power has the same economic-growth potential for the state, says Nebraska Farmers Union President John Hansen. Having the nation’s second-largest ethanol production capacity, Nebraska falls behind Iowa.