Posts Tagged ‘wind’
From “A Power Grid of Their Own: German Village Becomes Model for Renewable Energy” by Renuka Rayasam:
Werner Frohwitter drives his white Prius into Feldheim, parking halfway down the village’s one street in front of what looks like a shipping container. Behind the street is a field where 43 giant wind turbines loom over the village’s 37 houses. Frohwitter works for Energiequelle Gmbh, which owns the wind park. He greets a Russian camera crew and ushers them into the chilly container, which has become Feldheim’s impromptu visitor’s center. It’s the only sign of life in this otherwise quiet village. Inside, he uses posters on the wall to explain the town’s energy transformation for the Russian crew’s renewable energy documentary.
This town of 150 inhabitants, tucked away in the Brandenburg countryside some 60 kilometers (37.2 miles) southwest of Berlin seems like an unlikely tourist hotspot. It has no bars, museums or restaurants. But since the Fukushima nuclear disaster one year ago, Feldheim has become a beacon for cities across the world that want to shift their energy mix toward renewables.
Feldheim is the only town in Germany that started its own energy grid and gets all of its electricity and heating through local renewable sources, primarily wind and biogas. This mix of energy self-sufficiency and reliance on renewables attracted 3,000 visitors in 2011. Visitors came from North and South Korea, South America, Canada, Iran, Iraq and Australia. About half of the visitors are from Japan. Eri Otsu served as a translator for a group of Japanese energy analysts and politicians who came to Germany to see Feldheim. “Feldheim is not a charming Bavarian village; it is gray and they have little,” says Otsu, an organic farmer in southern Japan. Still, the group found Feldheim the most impressive of the three German villages they visited because it is energy independent and uses renewables. “They were amazed and said they had never seen anything like that,” Otsu says.
A Mayor’s Work
“People are here almost every day,” says Michael Knape, shifting through a stack of business cards on his desk. He sighs, saying that he can’t keep track of all the visitors. The 41-year-old, with dark hair and wide eyes that make his young face look even more boyish, is the mayor of Treuenbrietzen, the larger municipality where Feldheim sits. In many ways Knape’s work is typical of a small town mayor, dealing with residents when snow is not cleared fast enough and sometimes answering the phone at the city hall. What makes Knape different is that he is also a patient ambassador for Feldheim, convinced that investing in renewables is the only answer to the country’s energy dilemma.
After the disaster at the Fukushima nuclear power plant, Chancellor Angela Merkel planned a phase-out for Germany’s nuclear power plants and set the goal of requiring 35 percent of Germany’s energy to come from renewables by 2020, up from 20 percent at the time. Yet the federal government is now cutting funding for renewable energy projects and phasing out solar subsidies. [...]
A Series of Coincidences
It started with a few windmills in 1995. A series of coincidences transformed Feldheim from a backwater town in eastern Germany into a model renewable energy city. “Back in the 1990s no one expected it would get this far,” says Frohwitter. Feldheim’s strong wind and abundant land are pretty much the only reason that Michael Raschermann, head of Energiequelle Gmbh, decided to install a wind turbine in the village. Now the wind park has more turbines than the village has houses.
By 2008, after two years of planning, Feldheim built a €1.7 million biogas factory to be used for heat and fueled by slurry of unused corn and pig manure. The village received about half of the startup costs from a European Union program. Because farmers in Feldheim already grew corn and raised pigs, the biogas factory also benefits local agriculture. A furnace burning wood chips left over from felled trees in the local forest serves as a backup heat source when the temperature dips.
In 2008 Feldheim decided to take control of its own grid. Cutting out the middleman was a natural step since the town was producing all of its own energy right in its backyard. But when E.on refused to sell or lease its energy grid, Feldheim, with help from Energiequelle, had to build its own smart grid. They completed the grid in October 2010 with each villager contributing €3,000 ($3,972). Now Feldheimers pay about 31 percent less for electricity and 10 percent less for heating. The project has created about 30 jobs in Feldheim. [...]
Posted in Research by Kate Archdeacon on April 13th, 2010
Source: Environmental Research Web
When it comes to incorporating more wind power into electricity supply systems, a key worry is the renewable-energy source’s variability with time as wind speeds fluctuate. Now a US team has found that linking up offshore wind turbines spread over a distance of roughly 2,500 km down the eastern seaboard of the US could help smooth out this variability. “When location of wind farms and transmission are picked to make best use of large-scale meteorological patterns, there is a dramatic improvement in how steady we found the produced electric power to be,” Willett Kempton of the University of Delaware told environmentalresearchweb. “In five years of data, there was never an hour with no power production.” Not only would such wind farm interconnection reduce variability and remove periods of zero power production, it would also mean that any remaining variations in power output happened more slowly. This would give electricity suppliers more time to ramp up or down alternative sources or transmission links to meet consumer demand. Together with colleagues at Stony Brook University, US, the Delaware team analysed wind-speed data from eleven meteorological stations off the east coast, stretching from the tip of Florida in the south to Maine in the north. The researchers used this data to estimate power output from turbine arrays for the period 1998 to 2002.
Currently power supply operators use existing systems such as reserve generators and redundant power-line routes to manage the variability in wind-power output; as well as combining remote wind farms via electrical transmission, as discussed here, it’s also possible to employ energy storage, either at a central location or at distributed sites, for example through home heaters or plug-in cars, to smooth supply. There are plans for wind-turbine arrays with a total power capacity of about 2,500 MW off the eastern coast of the US. This amount, which is roughly equivalent to the output of a large coal or nuclear power plant, is only 0.1% of the available wind resource in the region. The researchers say that to connect these turbines would require 350 miles of submarine cable, which would add around $1.4 bn, less than 15%, to the estimated $10.5 bn installation costs. This supplement is roughly equivalent to levelling wind output via existing generation, which as a rule of thumb adds 10% of the wind-power cost for an electricity mix containing up to 20% wind power, and more for higher levels of wind power. And it’s much cheaper than smoothing output via energy storage schemes, such as pumping water into higher-level reservoirs – these have capital costs roughly equal to those of generation.
Read the full article on Environmental Research Web.
Posted in Research by Kate Archdeacon on December 1st, 2009
Source: Environmental Research Web
Image via physicsworld
From “Fish inspire wind farm configuration”, Edwin Cartlidge
Conventional wind turbines work best when located as far as possible from the destructive vortices of neighbouring turbines. However, a pair of scientists in the US have worked out that the performance of other kinds of turbine actually improves when they are placed close to one another, concluding that wind farms could therefore be made much smaller than they are today. The familiar propeller-like turbine with a horizontal axis of rotation can convert 50% or more of the energy from the wind that it is exposed to. In a wind farm, however, the wake from one turbine will disturb the air reaching the blades of its neighbours meaning that turbines must be placed far apart.
A less familiar family of turbines have a vertical axis of rotation. Individually, these vertical-axis turbines are less efficient than the horizontal-axis devices because only part of the turbine can be pushed by the wind at any one time, and they have therefore proven far less popular. However, these turbines have a significant advantage over the horizontal-axis variety – their power output can be increased when they are placed very close to one another. Now, Robert Whittlesey and John Dabiri of the California Institute of Technology have worked out how best to arrange such closely spaced turbines by drawing on the work of aeronautical engineer Daniel Weihs, who showed in the 1970s how fish save on energy by swimming within schools. Such fish form a series of offset rows, and Weihs found that fish get carried forward by the vortices created by the swimming motion of their two closest companions in the row immediately in front of them. Whittlesey and Dabiri wondered whether the relative spacing of vortices produced by an individual fish might serve as a good template for the arrangement of vertical-axis turbines within a wind farm and set up a computer model to test this idea.
Read the full article by Edwin Cartlidge.
Posted in Models by fedwards on June 3rd, 2009
This article, Harvesting the wind, was originally published by Suzanne LaBarre on 13 May 209 on the Metropolis website. It demonstrates an innovative model to integrate existing powerlines with wind energy. An alternative version of distributed systems perhaps? The full article can be found here.
Harvesting the wind
From the window of a TGV hurtling through France, the countryside flattens to a smudgeâ€”electrical towers rise and recede in clusters, and tall, lanky wind turbines seem to whip off pirouettes like a young Moira Shearer. Most passengers turn their heads, nodding off on a neighbor or burying their noses in Le Monde, but for a triÂumvirate of young designers, the sight is a view of the future. The passing turbines and pylons augur a new way to harness renewable energy in a country that relies almost entirely on nuclear power. â€œWhen weâ€™re riding on the train, we al-ways see pylons, and some turbines too,â€ NicÂola Delon says. â€œWe say, â€˜Both are here. Canâ€™t we mix them together?â€™â€