Monthly Archives: September 2012

Interconnector Links UK and Irish Grids Together

On Thursday, with officials from both nations attending, the first electricity connector between Ireland and Britain was opened. The 500 mW East-West Interconnector – developed by Irish transmission system operator Eirgrid – links Deeside in North Wales with Ireland’s County Meath.

The connection cost €570 million to build, 5 % under its €600 million budget.  It is  reported to be the single biggest energy infrastructural investment that has been done in Ireland since the commissioning of the hydroelectric Ardnacrusha power station in Co Clare 85 years ago. The cable connecting the two sides of land is approximately 260 km in length, and the underground and undersea link has the capacity to power 300,000 homes through it’s 500 mW.

There is already an existing interconnector between Scotland and Northern Ireland; the HVDC Moyle which went into service in 2001.  It also has a capacity of 500 mW, bringing the total capacity for electricity imports to Britain from across the Irish Sea to 1,000 mW.  The United Kingdom has electricity interconnectors with France and the Netherlands as well.  Plans are on-going to set up interconnectors with Norway, Spain and Iceland.

In July 2012, 14.8% of Irish electricity was being generated from renewable sources, up from 5% in 1990. Wind is the main source of renewable energy production in the country. In the UK only 3% of the electricity comes from renewable sources.  The interconnector will  export any surplus electricity from Irish wind power to help the UK increase the amount of renewables to help them reach the environmental  targets set by the EU. 

UK Energy secretary Ed Davey said Ireland was one of the few countries in the EU likely to generate more renewable energy than it needed to meet its targets, presenting opportunities for trading.

Trading on the interconnector will start on October 1st 2012.

See here a short film about the interconnector by construction corporation ABB

Via: www.ft.com/intl/cms/s/0/77897508-0322-11e2-a484-00144feabdc0.html#axzz27NjQxWuC

North Pole Could be Ice-free by 2016

Professor Peter Wadhams of Cambridge University, one of the world’s leading ice experts, has predicted the final collapse of Arctic sea ice in the summer of 2016.  In an email to the British newspaper the Guardian he calls for “urgent” consideration of new ideas to reduce global temperatures.

Wadhams, whose work is being financed by the US Office of Naval Research, has been researching the ice in artic waters for more than forty years. In 1996 he discovered that the North Pole ice had thinned by 40% since 1970.  Up and till now, all of Waldhams predictions have been proven correct.

Wadhams has been stressing  for years that the thickness and the condition of the North Pole ice can give more clues than satellite images of the ice from above.  In an email to the Guardian he writes about his findings: ” The main cause  of the ice melting is simply global warming: As the climate has warmed there has been less ice growth during the winter and more ice melt during the summer. At first this didn’t get noticed. The summer ice limits slowly shrank back, at a rate which suggested that the ice would last another 50 years or so. But in the end the summer melt overtook the winter growth such that the entire ice sheet melts or breaks up during the summer months.  This collapse, I predicted would occur in 2015-16 at which time the summer Arctic (August to September) would become ice-free. The final collapse towards that state is now happening and will probably be complete by those dates”.

Wadhams fears the implications are “terrible”:  “As the sea ice retreats in summer the ocean warms up (to 7C in 2011) and this warms the seabed too. The continental shelves of the Arctic are composed of offshore permafrost, frozen sediment left over from the last ice age. As the water warms the permafrost melts and releases huge quantities of trapped methane, a very powerful greenhouse gas so this will give a big boost to global warming.”

The extent of sea ice on the Arctic Ocean has shrunk this summer to it’s smallest amount since satellite records began in the 1970s, eclipsing a 2007 low.  The melt is part of a long-term retreat blamed, also by a U.N. panel, on man-made global warming, caused by the use of fossil fuels. The melting ice has opened new shipping routes between Atlantic and Pacific ports, and the United Nations Environmental Programme (UNEP) say that along with oil spills and shipwrecks, soot from ships could be a significant threat to the region.  The Arctic’s abundant supplies of oil, gas and minerals will, thanks to the melting ice, become newly accessible and it won’t be long before nations and corporations start competing for the area’s riches,

Waldhams finds it disturbing that politicians and the public are still attuned to the  threat of climate change. “CO2 levels are rising at a faster than exponential rate, and yet politicians only want to take utterly trivial steps such as banning plastic bags and building a few windfarms,” he said.

Via: www.guardian.co.uk/environment/2012/sep/17/arctic-collapse-sea-ice

MIT Develops Way to Help Clean Oil Spills

The Massachusetts Institute of Technology (MIT) has developed a new technique for magnetically separating oil and water that could be used to clean up oil spills. The idea was presented at the 13th International Conference on Magnetic Fluids in New Delhi yesterday.

Clean up and recovery from an oil spill still remains a challenge.  The last big oil spill, The Deep Water Horizon oil spill,  also know as the BP oil spill, occured in the Gulf of Mexico in 2010. It is the largest accidental marine oil spill in the history of the petroleum industry.  After this disaster, renewed interest emerged on finding new effective methods of cleaning up the spilled oil from the water.  Even a competition was born out of frustration over oil clean up efforts. Until now there have been three ways to combat an oil slick on the open sea; a mechanical approach, which comprises the use of a boom to corral and deflect oil and skimmers to collect it,  applying dispersants to the slick or, alternatively, burning the oil and manually removing it from the water.

The first tactic has been the preffered approach, because it is the only one removing the oil from the environment. The downside to it is that it is very labour  and equipement intensive and you only retrieve a small percentage of the spilled oil. Mechanical clean-up technology tends to  work exclusively in placid waters. In choppy waters the recovery efficiency is just 50%. So what you retrieve  from the water would be  a half water – half oil mixture.

When dispersants are used, they will disperse large amounts of certain oil types from the sea surface by transferring it into the water column. They will cause the oil slick to break up and form water-soluble micelles that are rapidly diluted. The oil is then effectively spread throughout a larger volume of water than the surface from where the oil was dispersed. It can also delay the formation of persistent oil-in-water emulsions. However, laboratory experiments showed that dispersants increased toxic hydrocarbon levels in fish by a factor of up to 100 and may kill fish eggs.

For the controlled burning of oil in open sea you need the right sea surface temperature and enough oil to achieve combustion that could be sustained. Usually oil is spread thin and wide on sea surfaces, so that faces a problem. And moreover, controlled burning does severely impact the air quality and releases all sorts of undesirable gasses into the atmosphere , including mercury.

The first method remains the best, but it is still difficult seperating the oil from the water. Suspending magnetic nanoparticles within the oil turns it into a magnetic liquid known as a ferrofluid. A great deal of research has been done on separating water and ferrofluids, because it seemed like a promising method of extracting oil from contaminated water.  The typical method involves pumping a water and ferrofluid mixture through a channel, while magnets outside the channel direct the flow of the ferrofluid, perhaps diverting it down a side channel or pulling it through a perforated wall. This approach can work if the concentration of the ferrofluid is known in advance and remains constant, which  unfortunately doesn’t apply in the case of contaminated water from an oil spill.

The MIT researchers made two modifications to this existing ferrofluid method. Instead of placing the magnets on the outside of the stream, they were immersed within it, and instead of being oriented parallel to the flow of the stream, they run perpendicular to it.

The magnets are permanent magnets, and they’re cylindrical. Due to the fact that a magnet’s magnetic field is strongest at its edges, the tips of each cylinder attract the oil much more powerfully than its sides do. In experiments the MIT researchers conducted in the lab, the bottoms of the magnets were embedded in the base of a reservoir that contained a mixture of water and magnetic oil; consequently, oil couldn’t collect around them. The tops of the magnets were above water level, and the oil shot up the sides of the magnets, forming beaded spheres around the magnets’ ends.

MIT’s  technology is supposed to improve the 50 % efficiency in choppy waters.  The magnetic separation method could be used in conjunction with existing oil recovery techniques such as skimming, which would perform an initial separation.  Collecting the 50 % oil and water in a confined space, then putting magnetic nanoparticles in the water and seperating the magnetic oil from the water, so you get clean water and magnetic oil. Then existing technology can be used to remove the magnetic nanoparticles from the oil and the oil can be recovered re-used.

In their experiments, the MIT researchers used a special configuration of magnets, called a Halbach array, to extract the oil from the tops of the cylindrical magnets. Whether the Halbach array would be the most practical way to remove oil from the cylindrical magnets in an actual oil-recovery system remains to be seen. The researchers also need to determine how much water gets dissolved in the oil, and how it can best be removed. “To our eye, you don’t see much moisture in there, but I’m sure that there is some moisture that adheres to it,” Markus Zahn, the Thomas and Gerd Perkins Professor of Electrical Engineering  Zahn says. “We might have to run it through multiple cycles.”

Shahriar Khushrushahi, a postdoc in MIT’s Department of Electrical Engineering and Computer Science and lead author on a paper says the technology’s simplicity makes it feasible for large scale manufacture and deployment at sea for days or weeks at a time, where electrical power and maintenance facilities are limited.

Watch MIT’s information video on the technology

Sources: MITTreehugger

www.popularmechanics.com/science/energy/coal-oil-gas/state-of-oil-cleaning-tech

http://www.gizmag.com/magnetic-oil-water-separation/24123/

and Wikipedia