A proposed high voltage electrical cable running across the floor of the North Atlantic Ocean to tap Iceland’s surplus volcanic geothermal energy would become the world’s longest underwater electrical cable, if it goes ahead. The cable would be a significant step towards a pan-European [...]]]>

A proposed high voltage electrical cable running across the floor of the North Atlantic Ocean to tap Iceland’s surplus volcanic geothermal energy would become the world’s longest underwater electrical cable, if it goes ahead. The cable would be a significant step towards a pan-European super grid, which may one day tap renewable sources as far afield as Scandinavia, North Africa and the Middle East. It’s argued that such a grid would be able to widely transmit energy surpluses from active renewable sources, thereby alleviating the need for countries to use (or build) back-up fossil fuel power stations to cater for peaks in demand when more local renewable sources aren’t particularly productive.

If a European super grid comes to fruition, energy surpluses will be big business. So it’s hardly surprising that both Germany and the United Kingdom are jostling for position at the other end of the Icelandic cable, with Norway and the Netherlands also having been mooted as potential connectees. That would necessitate a cable at least 745 miles (1198 km) in length, making it easily the longest electrical cable in the world.

The scheme, first proposed March of last year by Iceland’s largest energy producer Landsvirkjun, would aim to export five billion kilowatt-hours of energy per year for an estimated $350 to $448 million return. A feasibility study subsequently carried out has failed to find any terminal difficulties with the idea, and UK energy minister Charles Hendry is set to fly to Iceland in May to woo the relevant authorities.

An electrical link to Iceland is one of several international interconnectors either proposed or in progress in Europe, in addition to the fifteen or so routes that exist already (existing and planned connections can be seen on this map). Norway is a focal point for many of the confirmed forthcoming interconnectors which, unlike the proposed Iceland link, would see a two-way exchange of energy designed to further boost its energy security and that of its neighbors. The country is already linked via four North Sea interconnectors to Denmark, Germany, the UK, and the Netherlands—the latter being the current world record holder for longest submarine power link at 360 miles (580 km).

More ambitious are the proposed DESERTEC and Medgrid schemes to to interconnect countries and renewable energy sources on both the European and African sides of the Mediterranean Sea. German in origin, DESERTEC would involve the investment of more than $500 billion dollars by 2050, into 6500 square miles (nearly 17,000 sq km) of solar thermal collectors (plus a bit of wind) around the edge the Sahara Desert. The scheme could, it’s suggested, supply 15 percent of mainland Europe’s energy needs. Facts and figures for the French Medgrid scheme (conceptually very similar to DESERTEC) are rather more elusive, and interpretation varies as to whether the two schemes are complementary or in competition.

Conceptual sketch of the proposed DESERTEC energy system.

the Trans-Mediterranean Renewable Energy Cooperation (TREC)

A problem inherent to all long-distance electrical transmission: energy loss due to the resistance of the cables. Thanks to Joule’s first law, the problem is minimized by stepping up voltage, with a ten-fold increase resulting in a 100-fold loss reduction. The Norway-Netherlands link transmits AC at 300,000 and 400,000 volts.

Even the proposed Iceland interconnector, accounting for the worst case scenario of a 930-mile (1500-km) cable, falls well within the bounds of profitability according to the findings of a 1980s study which calculated the longest cost-effective distances for electrical transmission to be 2500 miles (4000 km) for AC and 4300 miles (7000 km) for DC. Official costs are yet to be tabled for the project.

The exportation of renewable energy is a logical next step for Iceland, which has done a grand job of getting its own house in order. The country currently meets 81 percent of its energy needs with domestic renewable sources—thanks in no small part to the country’s tremendous geothermal assets, sitting as it does on the Mid-Atlantic Ridge (which can have occasional less welcome consequences). The country plans to be free of fossil fuels in the near future.

Photograph by ThinkGeoEnergy

As part of its Battery 500 project — an initiative started by IBM in 2009 to produce a battery capable of powering a car for 500 miles — Big Blue has successfully demonstrated a light-weight, ultra-high-density, lithium-air battery.

In IBM’s lithium-air battery, oxygen is reacted with lithium to create lithium peroxide and electrical energy [...]]]>

As part of its Battery 500 project — an initiative started by IBM in 2009 to produce a battery capable of powering a car for 500 miles — Big Blue has successfully demonstrated a light-weight, ultra-high-density, lithium-air battery.

In IBM’s lithium-air battery, oxygen is reacted with lithium to create lithium peroxide and electrical energy (pictured above). When the battery is recharged, the process is reversed and oxygen is released — in the words of IBM, this is an “air-breathing” battery. While conventional batteries are completely self-contained, the oxygen used in an lithium-air battery obviously comes from the atmosphere, so the battery itself can be much lighter.

The main thing, though, is that lithium-air energy density is a lot higher than conventional lithium-ionbatteries: The max energy density of lithium-air batteries is theorized to be around 12 kWh/kg, some 15 times greater than li-ion — and more importantly, comparable to gasoline.

Therein lies the crux of IBM’s Battery 500 project: Current battery tech simply cannot come close to gasoline, which is why we’re surrounded by electric cars that are lumbered down by massive batteries that can only go 100 miles — and why gas still rules supreme. Eventually (in another 10 years or so), li-ion batteries could be replaced with li-air batteries that are a tenth of the size and weight, and yet last just as long — or, of course, li-air could replace gasoline.

Lithium-air batteries aren’t a new idea: They’ve been mooted since the 1970s, but the necessary tech was well beyond the capabilities of then-contemporary material science. Today, with graphene and carbon nanotubes and fancy membranes coming out of our ears, it seems IBM — with assistance from partners Asahi Kasei and Central Glass — now has the materials required to build a lithium-air battery. There is a video embedded below that details the electrochemical process of an li-air battery.

Supercomputers also played a big part in this breakthrough; IBM isn’t a battery-making company, after all.IBM Blue Gene/P supercomputers at IBM Research in Zurich and Argonne National Laboratory in Chicago were used to model and optimize the li-air chemistry. The battery prototypes themselves are being built at IBM Research Almaden, California.
httpv://youtu.be/8pMFLpiqPAc

“Metal oxides are cheap, abundant and ‘green,’” said Louis [...]]]> Harnessing the energy of sunlight can be as simple as tuning the optical and electronic properties of metal oxides at the atomic level by making an artificial crystal or super-lattice ‘sandwich,’ says a Binghamton University researcher in a new study published in the journal Physical Review B.

“Metal oxides are cheap, abundant and ‘green,’” said Louis Piper, assistant professor of physics at Binghamton University. “And as the study proved, quite versatile. With the right touch, metal oxides can be tailored to meet all sorts of needs, which is good news for technological applications, specifically in energy generation and flat screen displays.”

Here’s how it works: semiconductors are an important class of materials in between metals and insulators. They are defined by the size of their band gap, which represents the energy required to excite an electron from the occupied shell to an unoccupied shell where it can conduct electricity. Visible light covers a range of 1 (infrared) to 3 (ultraviolet) electron volts. For transparent conductors, a large band gap is required, whereas for artificial photosynthesis, a band gap corresponding to green light is needed. Metal oxides provide a means of tailoring the band gap.

But whilst metal oxides are very good at electron conduction, they are very poor “hole” conductors. Holes refer to absence of electrons, and can conduct positive charge. To maximize their technologically potential, especially for artificial photosynthesis and invisible electronics, hole conducting metal oxides are required.

Knowing this, Piper has begun studying layered metal oxides systems, which can be combined to selectively ‘dope’ (replace a small number of one type of atom in the material), or ‘tune’ (control the size of the band gap). Recent work revealed that a super-lattice of two hole-conducting copper oxides could cover the entire solar spectrum. The goal is to improve the performance whilst using environmentally benign and cheap metal alternatives.

For instance, indium oxide is one of the most widely used oxides used in the production of coatings for flat screen displays and solar cells. It can conduct electrons really well and is transparent. But it is also rare and very expensive. Piper’s current research is aimed towards using much cheaper tin oxide layers to get electron and hole conduction with optical transparency.

But according to Piper, his research shows that one glove will not fit all purposes.

“It’s going to be a case of some serious detective work,” said Piper. “We’re working in a world where physics and chemistry overlap. And we’ve reached the theoretical limit of our calculations and fundamental processes. Now we need to audit those calculations and see where we’re missing things. I believe we will find those missing pieces by playing around with metal oxides.”

By reinforcing metal oxides’ ‘good bits’ and downplaying the rough spots, Piper is convinced that the development of new and exciting types of metal oxides that can be tailored for specific applications are well within our reach.

“We’re talking battery storage, fuel cells, touch screen technology and all types of computer switches,” said Piper “We’re in the middle of a very important gold rush and its very exciting to be part of that race to strike it rich. But first we have to figure out what we don’t know before we can figure out what we do. One thing’s for sure: metal oxides hold the key. And I believe that we at Binghamton University can contribute to these efforts by doing good science and taking a morally conscious approach.”

A cool new concept being tested in the Abu Dhabi desert uses a wind turbine to condense water from the air and pump it into storage tanks for filtration and purification. The technology was created by Eole Water after its founder, Marc Parent, was inspired by the water he could [...]]]>
© Eole Water

A cool new concept being tested in the Abu Dhabi desert uses a wind turbine to condense water from the air and pump it into storage tanks for filtration and purification. The technology was created by Eole Water after its founder, Marc Parent, was inspired by the water he could collect from his air conditioner unit while living in the Caribbean. He began thinking of ways that water could be condensed from air in areas without access to grid power and the wind turbine concept was born.

The 30-kW wind turbine houses and powers the whole system. Air is taken in through vents in the nose cone of the turbine and then heated by a generator to make steam. The steam goes through a cooling compressor that creates moisture which is then condensed and collected. The water produced is sent through pipes down to stainless steel storage tanks where it’s filtered and purified.

© Eole Water

A prototype of the technology has been installed in Abu Dhabi since Octoberand has been capable of producing 500 to 800 liters of clean water a day from the dry desert air. Eole Water says that volume can increase to 1,000 liters a day with a tower-top system. The system requires wind speeds of 15 miles per hour or higher to produce water.

This technology uses a simple process that has been experimented with in a variety of designs, but this is the first powered by a wind turbine. That component makes it able to produce large quantities of clean water in areas that don’t have ready access to it without requiring grid power, which makes it especially promising for remote communities and disaster areas. Eole has already landed 12 industrial partners for manufacturing the turbines.

Narendra Modi, Chief Minister of Gujarat, revealed this Thursday via Twitter that the solar park had been switched on:

“Gujarat dedicates 600 [...]]]> Just 14 months ago, the Indian state of Gujarat announced that it was building a $2.3-billion solar park — the largest photovoltaic power station the world has seen so far.

Narendra Modi, Chief Minister of Gujarat, revealed this Thursday via Twitter that the solar park had been switched on:

“Gujarat dedicates 600 MW of solar power to the nation today. We are celebrating the launch of Agni V & dedication of 600 MW solar power park in Gujarat.”

“This achievement is not merely a step in the direction of power conservation, but it provides the world with a vision of how the power needs of future generations can be solved in an environment-friendly manner.”

The new addition to India’s electrical grid triples its current solar power capacity. The solar park is three times larger than the Chinese Golmud Solar Park, which held the record since it was finished in October 2011 with a total capacity of 200 MW.

This is one of many projects to come if India is to reach its green goals within 2020: 15% of India’s total energy consumption should come from renewable sources of energy. The country is currently at 6%.

The project has been a collaboration between 21 different companies, including several from the U.S. Another $400 million is reserved for renewable energy in the very same region where the new solar park operates. Modi says they are planning to encourage the development residential solar panels with a lot of this money.

The project is certainly a great addition to India and the rest of the world’s renewable energy capacity. However, the Gujarat solar park is very small compared to the planned TuNur project, part of the DESERTEC project. That will be a 2,000-MW concentrated solar power plant and is supposed to be operating in Tunisia by 2016.

Source: Clean Technica (http://s.tt/19Drq)

Human population growth has contributed to a 6 percent global drop in surface water sources such as lakes, rivers and [...]]]> When populations expand, the demand for fresh water rises. And over the past two decades, population growth has contributed to a 6 percent decline in worldwide surface water, according to a new study.

Subtropical and tropical equatorial areas like South America and South Asia – particularly China and India – contributed to more than half of the overall decrease in land surface water over the last two decades, said Catherine Prigent of the Observatoire de Paris, in France, and lead author of the study to be published in Geophysical Research Letters, a journal of the American Geophysical Union.

Taking water coverage data from multiple satellites, including several NOAA satellites, researchers noted the change in surface water over a 15-year period from 1993 to 2007.

Prigent and her fellow researchers found that important declines are often located in regions where the population increased significantly, likely due to the draining and destruction of wetlands for development and construction. Wetlands are known to filter hazardous chemicals and contain large of amounts of greenhouse gases like methane and carbon dioxide, gasses which are released when the wetlands are drained.

Prigent mentioned there may be additional causes of the decline, but other potential causes she investigated – including precipitation, evaporation and temperature – did not show as strong a link as population density.

A lack of other studies analyzing the global change of surface water means that it is difficult to tell if this decline is normal or greater than usual, Prigent said. Nevertheless, the past two decades of data show the decline is there. Recognizing the drop is only part of the process, she said, noting that more environmentally sustainable land-use planning is necessary.

“It’s important to be aware that the decline is there,” Prigent said. “The problem is how do you avoid that decline?”

They argue that the total volume of water in aquifers underground is 100 times the amount found on the surface.

The team have produced the most detailed map yet of the scale and potential of this [...]]]> Scientists say the notoriously dry continent of Africa is sitting on a vast reservoir of groundwater.

They argue that the total volume of water in aquifers underground is 100 times the amount found on the surface.

The team have produced the most detailed map yet of the scale and potential of this hidden resource.

Writing in the journal Environmental Research Letters, they stress that large scale drilling might not be the best way of increasing water supplies.

Across Africa more than 300 million people are said not to have access to safe drinking water.

Demand for water is set to grow markedly in coming decades due to population growth and the need for irrigation to grow crops.

Freshwater rivers and lakes are subject to seasonal floods and droughts that can limit their availability for people and for agriculture. At present only 5% of arable land is irrigated.

Now scientists have for the first time been able to carry out a continent-wide analysis of the water that is hidden under the surface in aquifers. Researchers from the British Geological Survey and University College London (UCL) have mapped in detail the amount and potential yield of this groundwater resource across the continent.

Helen Bonsor from the BGS is one of the authors of the paper. She says that up until now groundwater was out of sight and out of mind. She hopes the new maps will open people’s eyes to the potential.

“Where there’s greatest ground water storage is in northern Africa, in the large sedimentary basins, in Libya, Algeria and Chad,” she said.

“The amount of storage in those basins is equivalent to 75m thickness of water across that area – it’s a huge amount.”

Ancient events

Due to changes in climate that have turned the Sahara into a desert over centuries many of the aquifers underneath were last filled with water over 5,000 years ago.

The scientists collated their information from existing hydro-geological maps from national governments as well as 283 aquifer studies.

The researchers say their new maps indicate that many countries currently designated as “water scarce” have substantial groundwater reserves.

However, the scientists are cautious about the best way of accessing these hidden resources. They suggest that widespread drilling of large boreholes might not work.

Dr Alan MacDonald of the BGS, lead author of the study, told the BBC: “High-yielding boreholes should not be developed without a thorough understanding of the local groundwater conditions.

“Appropriately sited and developed boreholes for low yielding rural water supply and hand pumps are likely to be successful.”

With many aquifers not being filled due to a lack of rain, the scientists are worried that large-scale borehole developments could rapidly deplete the resource.

According to Helen Bonsor, sometimes the slower means of extraction can be more efficient.

“Much lower storage aquifers are present across much of sub-Saharan Africa,” she explained.

“However, our work shows that with careful exploring and construction, there is sufficient groundwater under Africa to support low yielding water supplies for drinking and community irrigation.”

The scientists say that there are sufficient reserves to be able to cope with the vagaries of climate change.

“Even in the lowest storage aquifers in semi arid areas with currently very little rainfall, ground water is indicated to have a residence time in the ground of 20 to 70 years.” Dr Bonsor said.

“So at present extraction rates for drinking and small scale irrigation for agriculture groundwater will provide and will continue to provide a buffer to climate variability.”

The publication of the new map was welcomed by the UK’s secretary of state for international development, Andrew Mitchell.

“This is an important discovery,” he said. “This research, which the British Government has funded, could have a profound effect on some of the world’s poorest people, helping them become less vulnerable to drought and to adapt to the impact of climate change.”