Wind energy provides 8% of Europe's electricity

 

EU's grid connected cumulative capacity in 2014 reached 129 GW, meeting 8% of European electricity demand, equivalent to the combined annual consumption of Belgium, the Netherlands, Greece and Ireland. According to a JRC report, the impressive growth of the industry will allow at least 12% electricity share by 2020, a significant contribution to the goal of the European energy and climate package of 20% share of energy from renewable sources. The 2014 JRC wind status report presents the technology, market and economics of the wind energy sector with a focus on the EU. Wind power is the renewable energy which has seen the widest and most successful deployment over the last two decades, increasing the global cumulative capacity from 3 GW to 370 GW. Last year represented an annual record with 52.8 GW of wind turbines capacity installed worldwide, a 48% increase compared to 2013 and 17% over the 2012 record of 45.2GW. With 23.2 GW of new installations and a market share of 44%, China is well ahead of EU's member states which together installed 13.05 GW. The EU however still leads in cumulative capacity and its 129 GW onshore and offshore wind installations, allowed six countries -- Denmark, Portugal, Ireland, Spain, Romania and Germany -- to generate between 10 and 40 % of their electricity from wind. European turbine manufacturers accounted for 78% of the non-China world market in 2014. In a context of high competition and diminishing turbine prices, manufacturers managed to improve their balance sheet thanks to better cost management and reduced raw materials costs. The cost of generating wind energy continues its downward trend, highly favoured by a reduction in the cost of project financing. More information: https://ec.europa.eu/jrc/en/publication/eur-scientific-and-technical-research-reports/2014-jrc-wind-status-report Story Source: The above post is reprinted from materials provided by European Commission, Joint Research Centre (JRC). Note: Materials may be edited for content and length.

Are bridge-mounted wind turbines a viable option?

 

An artist's take on how wind turbines underneath bridges might look (Credit: José Antonio Peñas/Sinc) Wind turbines might be common sight all around the world, but situating them in open fields or on breezy ridges isn't always a practical option. Ideas like placing turbines under bridges have been proposed, but is that a viable alternative? According to new research out of Europe, the answer is yes. The study is based in models and computer simulations, which were carried out by researcher Oscar Soto and his colleagues in Kingston University (London) The researchers from Spain and the UK, used the Juncal Viaduct in the Canary Islands as a basis for computer simulations designed to establish whether the wind blowing between the pillars on bridges is sufficient to move turbines and create energy. The study showed that the best way to create power would be to use two different-sized turbines, or even to create a matrix of 24 small turbines because of their low weight and the amount of power that can be produced by each unit. In terms of practicality, however, the study suggests that the best option would be to use two identical medium sized 0.25 MW turbines, which could theoretically generate enough energy to power 450-500 homes, as well as reduce CO2 emissions compared with fossil fuel sources. "This kind of installation would avoid the emission of 140 tons of CO2 per year, an amount that represents the depuration effect of about 7,200 trees," said researcher Oscar Soto. A paper outlining the findings has been published in the journal Renewable and Sustainable Energy Reviews. Source: Sinc

Superconducting coil to slash costs and improve efficiency of direct-drive wind turbines

 

Dr Shahriar Hossain is developing a wind turbine that uses a magnesium diboride superconducting coil Conventional offshore wind turbines are expensive and complicated pieces of machinery – in a large part because of their complex and maintenance-intensive gearboxes. Dr Shahriar Hossain from the University of Wollongong (UOW) in Australia is looking to slash production costs and drastically improve efficiency replacing these gearboxes with a superconducting coil. Wind turbine gearboxes connect the low-speed shaft, which is turned by the rotation of the blades, to the high-speed shaft that drives the generator, increasing the rotational speed of the low-speed shaft from around 30-60 rpm to the rotational speed required by the generator to produce electricity – which is usually around 1,000-1,800 rpm. To avoid the cost, maintenance and efficiency-loss problems associated with the use of gear boxes, Dr Hossain, a materials scientist from the UOW's Institute of Superconducting and Electronic Materials with funding by the Australian Research Council in 2013 under the Discovery Early Career Researcher Award (DECRA) scheme, is developing a magnesium diboride superconducting coil made from magnesium and boron that he says is very cheap and easy to manufacture and would allow wind turbines to operate with no gearbox at all. Unlike a conduction loop made of conventional copper wire that loses about seven to 10 percent of energy due to resistance when an electric current is sent into it, a superconducting loop would have no loss of energy as it has no electrical resistance. This would allow the current to circulate indefinitely, even after the power is cut off. When we reached out to Dr Hossain to ask about the problems surrounding the low temperatures required for the superconductors to work, he admitted this is the most challenging part of developing the system around the magnesium diboride superconducting coil. To address the problem he plans to use off-the-shelf cryocoolers to cool the rotating components of the system in a two-stage process. The first crycooler will drop the temperature to -218° C (-360° F), while the second will then lower it further to -253° C (-424° F). Dr Hossain says that in comparison to well-established niobium-based superconductors, his magnesium diboride-based superconductors have achieved very high critical current density. Despite this two cryocooler arrangement, Dr Hossain says it will still be cheaper than using high temperature superconductors (HTS), which can exhibit superconductivity at temperatures as high as -135° C (-211° F), but cost around AUD$25 (US$21) a meter. Dr Hossain's US industry partner, Hyper Tech Research, predicts that magnesium diboride coil will cost just $1 (US$0.85) a meter to manufacture by 2015. Additionally, unlike niobium-based low temperature superconductors (LTS) that require increasingly pricey liquid helium to operate, Dr Hossain says the cryocooler system will run with ambient temperature helium gas supplied by compressors and entering into the rotor and returning through a rotary coupling in a closed loop. Dr Hossain says that 10 MW-class wind turbines will require up to 200 km (124 mi) of superconducting coil to generate electricity, with each HTS-based coil costing between AUD$3 to $5 million (US$2.5 to $2.4 million) to manufacture. However, he claims that the same length of magnesium diboride superconducting coil would cost just AUD$180,000 (US$153,000), with that figure expected to drop significantly. "Australia desperately needs sustainable energy sources," says Dr Hossain. "Wind is cheap, clean and we can get it day and night and on rainy and sunny days. And considering Australia has more than 35,000 km of coastline, there is ample room for offshore wind farms. With industry support, we could install superconducting offshore wind turbines off the coast of Australia in five years, no problem." Source: University of Wollongong

Ahoy, offshore wind: Advanced buoys bring vital data to untapped energy resource

 

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Research on the High Seas: Pacific Northwest National Laboratory staff conduct tests in Sequim Bay, Washington, while aboard one of two new research buoys being commissioned to more accurately predict offshore wind’s power-producing potential.

Two massive, 20,000-pound buoys decked out with the latest in meteorological and oceanographic equipment will enable more accurate predictions of the power-producing potential of winds that blow off U.S. shores.

The bright yellow buoys -- each worth about $1.2 million -- are being commissioned by the Department of Energy's Pacific Northwest National Laboratory in Washington state's Sequim Bay. Starting in November, they will be deployed for up to a year at two offshore wind demonstration projects: one near Coos Bay, Oregon, and another near Virginia Beach, Virginia.

"We know offshore winds are powerful, but these buoys will allow us to better understand exactly how strong they really are at the heights of wind turbines," said PNNL atmospheric scientist Will Shaw. "Data provided by the buoys will give us a much clearer picture of how much power can be generated at specific sites along the American coastline -- and enable us to generate that clean, renewable power sooner."

Offshore wind is a new frontier for U.S. renewable energy developers. There's tremendous power-producing potential, but limited information is available about ocean-based wind resources. DOE's Office of Energy Efficiency and Renewable Energy purchased the buoys to improve offshore turbine performance in the near term and reduce barriers to private-sector investment in large-scale offshore wind energy development in the long term. The buoys were manufactured by AXYS Technologies, Inc., in Sydney, British Columbia.

A recent report estimated the U.S. could power nearly 17 million homes by generating more than 54 gigawatts of offshore wind energy, but more information is needed. Instruments have long been sent out to sea to measure winds on the ocean's surface, but the blade tips of offshore wind turbines can reach up to 600 feet above the surface, where winds can behave very differently.

The buoys carry a bevy of advanced instruments, including devices called lidar, which is short for light detection and ranging, to measure wind speed and direction at multiple heights above the ocean. Other onboard instruments will record air and sea surface temperature, barometric pressure, relative humidity, wave height and period, and water conductivity. Subsurface ocean currents will also be measured with acoustic Doppler sensors.

All of these measurements will help scientists and developers better understand air-sea interactions and their impact on how much wind energy a turbine could capture at particular offshore sites. The data will also help validate the wind predictions derived from computer models, which have thus far relied on extremely limited real-world information.

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Story Source:

The above story is based on materials provided by Pacific Northwest National Laboratory. The original article was written by Frances White. Note: Materials may be edited for content and length.

Wind Turbines Generate “Upside-Down” Lightning

 

By Geoffrey Giller | March 3, 2014 |  

 

 

Lightning strikes have been known to incapacitate wind turbines by destroying their blades. But while most tall structures are prone to lightning strikes, wind turbines seem to be especially susceptible. Recently scientists captured high-speed footage of these strikes, and they discovered that the wind turbines may in fact be the architects of their own demise: the nature of the turning turbine helps to cause these strikes.

Typically when lightning strikes a tall object, the strike is initiated from the cloud. A channel of negatively charged plasma, called a negative downward leader, moves from areas of negative charge in a storm cloud down toward a positively charged building, tree or wind turbine. As the negative leader nears the structure, it induces a positive upward leader, which jumps up to meet the negative leader. The connection forms a current, and the bright lightning flash we observe is actually to the result of a shock wave flowing up the connected channels, called a return stroke.

In the case of these wind turbines, positive upward leaders are generated from the turbine blades in the absence of a negative downward leader from the clouds above.

In the paper describing their findings, published online February 6 in the Journal of Geophysical Research, the researchers describe the phenomenon they think is responsible for this lightning. When tall objects build up a positive charge underneath a negatively charged storm cloud, they form a cloud of positively charged ions, which helps to dissipate the electric field around them. But, says Oscar van der Velde, a researcher at the Polytechnic University of Catalonia and a co-author of the paper, “if your blade can escape this cloud of ions, then the field will remain high. And if the field is high enough, you can trigger a real lightning flash.”

The lines that stay illuminated have formed currents with the clouds above. Still, there is no bright flash and thus no return stroke, van der Velde says: “If you get a return stroke… it saturates the image.” This is just as well for the turbines because the return stroke is the most damaging part of a lightning strike. Yet “even discharges without return strokes can cause progressive damage to the turbine materials, ultimately leading to their failure,” van der Velde points out.