Helping The Environment to Reduce Global Warming
TUESDAY, 24 FEBRUARY 2009
Solar power heats up energy possibilities
By Matt Ford
Just west of Seville in Spain, a sea of giant mirrors is reflecting the sun’s energy to provide “concentrated solar power” (CSP) while illuminating the path to a new wave of green energy projects.
The 624 carefully positioned mirrors reflect the sun’s heat towards a 50 meter-tall central tower where it is concentrated and used to boil water into steam.
The superheated steam is then used to turn a turbine that can produce up to 11 megawatts of electricity — enough power for 6,000 homes — according Solucar, the Spanish company that has built the power plant.
While traditional solar panels, photovoltaic cells, convert the sun’s power directly into electricity, CSP focuses power from a wide area and uses the vast heat generated to make electricity in a similar way to that produced from coal or oil.
The Spanish tower, known as PS10, is the first phase of an ambitious development. By 2013 it is hoped that additional towers will create a “solar farm” with an output of 300 megawatts, which would be enough power for 180,000 homes, or equivalent to the entire population of nearby Seville.
This $1.5 billion project is the largest commercial CSP station in the world — so far.
But many believe the technology will soon take off in areas of continuous hot sun and clear skies, offering a cheaper and more efficient alternative to photovoltaic cells, and bringing jobs and money to arid, often depressed areas.
CSP also produces no greenhouses gasses and the only pollution is visual. The European Union has invested over $31 million in CSP research over the last ten years.
At least 50 CSP projects have been given permission to begin construction across Spain. By 2015 the country may be producing two gigawatts of electricity from CSP, and employing thousands in the industry.
One of the strengths of CSP is that it allows the construction of power stations on a scale that can match many fossil fuel based plants, and for an investment far less than that required to install the equivalent wattage of photovoltaic cells.
There is also the possibility that production can keep going around the clock — even when the sun has gone down.
Solucar is currently testing technology at a plant near Granada that will pump 50 percent of the electricity generated in the day into the Spanish national grid, and use the other 50 percent to melt salt, which will then act as a kind of battery, storing the sun’s power. When dusk falls, the heat stored in the molten salt can be used to generate power through the night.
“These technologies excite me,” says Dr Jeff Hardy, Network Manager at the UK Energy Research Council.
“One of the real advantages is that you can get a decent sized power plant.
“The main challenge with the technology is working with extreme heat, but then a lot of the back-end is very similar to a traditional fossil-fuel generation; you are after all just dealing with water heated to make steam and drive a turbine.”
Concentrating on promoting CSP worldwide
As America looks to increase the contribution of renewables to its overall energy mix — a key part of the Obama plan before the recession turbocharged Government funding for such “green” infrastructure projects — the potential of CSP technology is obvious.
The Spanish company responsible for the Sanlucar la Mayor plant has seen the potential and created Solucar Power, Inc., a subsidiary aiming to develop the market in the USA.
There is already a huge Solar Energy Generating Systems’ CSP station in the Mojave Desert, California; Spanish firm Acciona has built a plant near Las Vegas. Many more are surely on their way.
One bold projection estimates that a single plant 100 miles by 100 miles located in the American South West could generate enough electricity for the whole country.
It would obviously be a huge undertaking — politically, financially and scientifically — but it’s not hard to imagine such a scheme finding a home in the nation’s vast, empty quarter.
Other equally arid areas may also find themselves transformed, and CSP may be able to offer valuable foreign earnings for drought-stricken Africa — while giving Europe the green energy it needs. According to Dr Hardy the technology has a ready application, given the right political, environmental and economic context.
“Concentrated Solar Power is proven to do well in countries like Spain with a favorable government policies and the right climate,” he says.
“I can certainly see the potential for extended networks linking together, and the idea of a North African grid linking renewable resources is a real possibility.”
Providing power, jobs and money
The Sahara, the world’s largest desert, is fringed by some of the poorest countries in the world and the harsh environment has always been seen as a problem, with it’s vast, waterless interior regularly reaching temperatures of over 45 degrees Celsius.
But with large-scale CSP projects, suddenly all that empty space, with its year-round clear skies and hot sun, has a value that could transform local economies.
It could potentially turn Africa into a net exporter of energy to power-hungry Europe, and perhaps even do for countries in North Africa what oil did for Saudi Arabia.
The sums are dizzying. Estimates vary, but one projection from the German Aerospace Agency puts the amount of solar energy stored in just one per cent of the Sahara — 35,000 square miles, or a piece of land slightly smaller than Portugal — as having the potential to yield more power than all the world’s existing power plants combined.
Already Spanish firms are exporting CSP technology to Morocco and Algeria, and a British consortium, the Sahara Forest Project, is testing the technology in the deserts of Oman.
Costs and benefits
However, there is a problem: at the moment costs are still very high. But they are falling as plants get bigger, the technology is perfected and economies of scale kick in.
Even so, any plans to power Europe from the Sahara would require a vast infrastructure of CSP plants and cables laid across the Mediterranean — requiring billions upon billions of dollars in investment.
Such sums will only be possible through international co-operation on a huge scale. But on a smaller, more local scale a simple change in the way electricity generators are paid has been hugely effective in boosting renewable power.
In Spain and other European countries investment has been encouraged by Governments creating what’s known as a “feed in tariff,” which pays companies a premium for power sold to the national grid generated by renewable means for a fixed period of time. This enables investors to pay back up front costs more quickly.
Where they have been introduced they have brought about a huge increase in renewable power: Germany has 200 times as much solar energy as Britain, generates 12 percent of its electricity from renewables, and has created a quarter of a million jobs in the sector.
We’re a long way from a future where the Sahara becomes the world’s largest source of renewable electricity, and the American South West is covered in mirrors lighting and powering cities across the continent.
There are many huge issues yet to resolve, but with small steps, we may be moving towards it.
Source: The San Francisco Tesla Society’s e-Home Page:
(Monday, February 2, 2009)
by Rory Callinan
(Brisbane Time Magazine)
Melbourne recorded its hottest ever three-day heatwave after the temperature hit 43.8 °C (110.84 °F), the third day above 43 °C.
In the final days of 2008, residents of Australia’s southeast might have been forgiven for thinking summer had finished early. On the island state of Tasmania in the far south, freezing gales blew, blanketing mountains with snow. In the state of Victoria, in the southeastern corner of the mainland, the number of sunny hours a day dropped from the normal 8.3 to a mere seven. “Where has our summer gone,” moaned a newspaper report, while some readers commented that it made you wonder if global warming was real.
Three weeks later and the complaints are rather different. A scorching northwesterly wind has blasted much of southeastern Australia for almost a week, creating the worst heat wave in the region for 70 years. Dozens of people reportedly died in the heat, many of them elderly. More than half a million homes and businesses lost power for days, railway lines buckled and bushfires burned tens of thousands of acres and destroyed at least 29 homes. “We’re in uncharted waters, unprecedented condition. It’s the hottest week since records began,” the Premier (Governor) of Victoria John Brumby told reporters as he toured bushfire ravaged areas over the weekend. (See “Australia’s Hidden Islands”.)
In South Australia, Premier Mike Rann warned: “Everyone has a responsibility to care for the elderly and children who were the most vulnerable.” He also had to explain why the state’s power supply had collapsed as tens of thousands of residents turned on their air conditioning.
The heat wave began on Jan. 28. In Adelaide, South Australia’s capital, 1.1 million inhabitants baked as the capital recorded its hottest day in 70 years and more than 26 sudden deaths were reported by the South Australian ambulance service. At one point the mercury tipped 114 °F (45.7 °C). The night brought little respite with temperatures dropping to 93 °F (33.9 C.), the hottest night in the city on record. (Raising the Bar on Fighting Climate Change.)
Melbourne experienced its hottest week since the mid 1800s when temperature measurements were first taken. Victorian Police said that at least six people could have died from heat-related conditions. The economic cost to Victoria was expected to top $62 million. Matches at the Australian Open tennis tournament in Melbourne were delayed when organizers closed the centre court for 45 minutes. Commuter trains were thrown into chaos as lines buckled and power blackouts halted services.
Victoria-based Weather Bureau meteorologist Dr Harvey Stern blamed weeks of westerly winds for blocking colder blasts of air that would normally reduce temperatures. “It’s very unusual for Melbourne. The only similar heat wave was in 1908 but that wasn’t as hot,” he says.
To make matters worse, bushfires fanned by the northwesterly winds raged through tinder dry inland regions. Near the Strzelecki Mountain range, about 62 miles (100 km) southeast of Melbourne, arsonists were blamed for starting a fire that burned out more than 15,000 acres and cut a swathe through the tiny town of Boolarra. Boolarra resident Peter Stasinowsky, who stamped out embers with his feet and used a garden hose to save his home, described the blaze as “bloody huge”(read “In Tongues of Flame”).
“It came over the hill pretty ferociously and it jumped over into the centre of town where there’s a bit of bush. I wouldn’t hazard a guess how big it was. They had a hell of a fight to stop it. The heat had something to do with it but we think it was deliberately lit,” says the local builder.
Even Australia’s Prime Minister Kevin Rudd was confronted with the issue when an elderly parishioner collapsed near him on Feb. 1, during a church service in the Australian capital Canberra. In what was a dream photo op for any politician, Mr Rudd was photographed carrying the parishioner out of the church and later urged residents to “pop in and check” on their neighbors in the extreme heat.
Australia’s Minister for Climate Change Penny Wong told the media the heat wave was “consistent with climate change, and all of this is consistent with what scientists told us would happen.” But some readers remained skeptical. “One swallow does not make a summer, a few stinking awful days doesn’t mean the climate is changing either,” one person emailed to the Canberra Times. It was not clear where in Australia he lived.
Link to Time Magazine article: http://www.time.com/time/world/article/0,8599,1876299,00.html
(Report from :
(Quote: Australian Broadcasting Commission News,Tue Jan 27, 2009)
..Melbourne has not had three days in a row above 40 since 1959.
The mercury is expected to reach 38 today before climbing to 41 tomorrow then dropping back slightly to 40 until Sunday when it should be a relatively cool 31.
Senior forecaster at the Bureau of Meteorology, Terry Ryan, says it also looks like it will be one of the driest Januaries on record.
“It’s very dry, we’ve only had 0.8 of a millimetre, the driest ever was 1932 at 0.3 of a millimetre, so at this stage it’s the second driest January in 150 years,” he said.
27 January 2009
Victorians are preparing for a savage summer blast not felt for a century.
Melbourne is expecting a top temperature of 38 degrees on Tuesday, with forecasters then predicting four consecutive days above 40 degrees.
Bureau senior forecaster Terry Ryan said the week’s weather could easily be one for the record books.
“We had three days in a row above 40 in 1959 in January,” Mr Ryan told AAP.
“The next one was five days above 40 in 1908, so it would be the longest stretch of hot weather in January in 100 years.”
The Country Fire Authority (CFA) has warned of extreme fire conditions brought on by the hot, dry blast.
CFA state duty officer Gregg Paterson said a spate of urban-rural fires in Carrum Downs and Langwarrin and in central Victoria last week were indicative of more to come.
“The fire behaviour in those fires was very extreme and another good indicator that the conditions are right for a fairly major type fire event,” Mr Paterson told AAP.
“We’re expecting hot, dry conditions pretty much from today onwards right through to next weekend, with temperatures well into the high 30s.”
Residents of northern Queensland are battening down as Tropical Cyclone Charlotte dumps torrential rain across the gulf region.
The cyclone, which formed in the Gulf of Carpentaria early on Sunday, is expected to cross the sparsely populated eastern gulf coast south of Kowanyama early on Monday.
The Bureau of Meteorology has issued a cyclone warning for coastal communities between Aurukun in Cape York and the Northern Territory/Queensland border.
It is expected to cross the coast as a strong category two cyclone but will weaken to a rain depression as it continues to moves towards the east coast, which includes population centres such as Cairns.
Emergency services have been placed on alert for flooding.
Acting Emergency Services Minister Andrew Fraser said falls of up to 300mm were expected overnight between Cardwell and Mossman.
He said State Emergency Service volunteers in the far north were on standby to deal with flooding waters and other emergencies.
About a third of Queensland is already besieged by floodwaters following heavy rain in the state’s north west last week.
Mr Fraser said additional rain from Charlotte could mean many properties in the gulf and western regions would remain isolated for an extended period.
He said additional arrangements may be needed to provide supplies to flood-hit properties.
“Given the level of rainfall to date, given the damage to road infrastructure already and given the time that some people have been isolated, all of that adds up to a more difficult situation.”
It’s no simple matter to figure out how regional changes in precipitation, expected to result from global climate change, may affect water supplies. Now, a new analysis led by MIT researchers has found that the changes in groundwater may actually be much greater than the precipitation changes themselves.
For example, in places where annual rainfall may increase by 20 percent as a result of climate change, the groundwater might increase as much as 40 percent. Conversely, the analysis showed in some cases just a 20 percent decrease in rainfall could lead to a 70 percent decrease in the recharging of local aquifers - a potentially devastating blow in semi-arid and arid regions.
But the exact effects depend on a complex mix of factors, the study found - including soil type, vegetation, and the exact timing and duration of rainfall events - so detailed studies will be required for each local region in order to predict the possible range of outcomes.
The research was conducted by Gene-Hua Crystal Ng, now a postdoctoral researcher in MIT’s Department of Civil and Environmental Engineering (CEE), along with King Bhumipol Professor Dennis McLaughlin and Bacardi Stockholm Water Foundations Professor Dara Entekhabi, both of CEE, and Bridget Scanlon, a senior researcher at the University of Texas. The results are being presented Wednesday, Dec. 17, at the American Geophysical Union’s fall meeting in San Francisco.
The analysis combines computer modeling and natural chloride tracer data to determine how precipitation, soil properties, and vegetation affect the transport of water from the surface to the aquifers below. This analysis focused on a specific semi-arid region near Lubbock, Texas, in the southern High Plains.
Predictions of the kinds and magnitudes of precipitation changes that may occur as the planet warms are included in the reports by the Intergovernmental Panel on Climate Change (IPCC), and are expressed as ranges of possible outcomes. “Because there is so much uncertainty, we wanted to be able to bracket” the expected impact on water supplies under the diverse climate projections, Ng says.
(Note: This story has been adapted from a news release issued by the Massachusetts Institute of Technology)
(5 January 2008)
Scientists at the Georgia Institute of Technology have discovered a new climate pattern called the North Pacific Gyre Oscillation. This new pattern explains, for the first time, changes in the water that are important in helping commercial fishermen understand fluctuations in the fish stock. They’re also finding that as the temperature of the Earth is warming, large fluctuations in these factors could help climatologists predict how the oceans will respond in a warmer world. The research appears in the April 30 edition of the journal Geophysical Research Letters.
“We’ve been able to explain, for the first time, the changes in salinity, nutrients and chlorophyll that we see in the Northeast Pacific,” said Emanuele Di Lorenzo, assistant professor in Georgia Tech’s School of Earth and Atmospheric Sciences.
Since 1945, fishermen in the California current of the Pacific Ocean have been tracking temperature, salinity and nutrients, among other things, in the ocean to help them predict changes in fish populations like sardines and anchovies that are important for the industry. Studying this data, along with satellite images, Di Lorenzo discovered a pattern of current that he named the North Pacific Gyre
Recent satellite data suggest that this current is undergoing intensification as the temperature of the Earth has risen over the past few decades.
“Although the North Pacific Gyre Oscillation is part of a natural cycle of the climate system, we find evidence suggesting that its amplitude may increase as global warming progresses,” said Di Lorenzo.
Change is small but was enough to cause upwelling, according to study
By Michael Reilly
updated Nov. 12, 2008
Generating wind power at sea may disturb ocean currents and marine ecosystems, according to a new study.
Offshore wind farms are common in Europe; Denmark, The Netherlands, and the United Kingdom all have several active installations. Wind power in the United States is currently confined to dry land, but three installations are planned off the coast of New Jersey, Rhode Island and Delaware, totaling about 1,500 megawatts of generating capacity.
Extracting energy from wind changes regional air currents, which can in turn affect how the nearby ocean circulates, according to Goran Brostrom of the Norwegian Meteorological Institute in Oslo.
In a paper published this month in Journal of Marine Systems, Brostrom shows in a model that winds swirling at 11 to 22 miles per hour downwind of large farms are uneven. As they blow over the ocean they can roil the waters, causing upwelling.
The change in currents seems small — a nudge of just 3.3 feet per day — and the wind farms have to be around 1.9 square miles. But Brostrom said the effect is enough to bring nutrient-rich waters up from the depths, which marine life can thrive on.
“I think you will see a large effect over time,” he said. “You will get more plankton blooming, and you will see more vibrant life overall at that place.”
Plankton blooms are infamous for causing toxic red tides and for sucking oxygen out of the water. But they can also be food sources for larger animals.
“Whether or not this is a good thing is a matter of debate,” Brostrom said. Though he stressed that the goal for any man-made object should be to minimize environmental impact, he added: “I’m an optimist; I think this could be beneficial to local fisheries.”
Such dreams of wind farms enriching ocean wildlife — or impacting it in any way — may be a bit premature, said Michael Dvorak of Stanford University. For one thing, all current farms are situated in water far shallower than the 98-foot depth assumed in Brostrom’s paper. Some deeper farms have been proposed, but maintenance costs skyrocket the further from shore windmills are.
And Brostrom’s study is a very general model — ocean currents and marine life could be affected in very different ways depending on the location of the farm.
by Jane Burgermeister, European Correspondent
Fleets of 50 tidal power plants, each with an installed power of 20 megawatts (MW), anchored far out on the ocean could be used to generate electricity for hydrogen electrolysis, and so supply the world with vast quantities of clean energy in years to come if a pilot project in Italy is successful, scientists say.
Because the power generated by tides is predictable, the device can be a reliable form of baseload power for a national grid.
A 500-kilowatt (kW) tidal power prototype that could be scaled up for ocean use is set to be tested next August in the Strait of Messina, a stormy stretch of sea separating Italy’s mainland from Sicily.
If the trial is successful, an even more powerful tidal power plant could be ready for mass production in about five years time, and installed not just in the seas off Italy but also in the Gulf of Florida and other coastal sites with stronger currents.
Tests so far of the Sea Power tidal device on open sea have been successful, said Werner Ebner from Fri-El Green Power, the company based Italy and developing the Sea Power power plant.
“These tidal power plants are an economical way of producing electricity. The system is comparatively inexpensive to build and also to maintain, not least because it is based on modules, which can also be easily transported,” he said.
The tidal power plant has an electricity generator that is located on a floating platform, held in place by devices fixing it to the bottom of the sea.
Attached to the platform are four cables; each one of the four cables extends for the same length behind the platform and has five buoys placed at regular intervals. (See top view image, above.) These five buoys contain electrical and other equipment for the five turbines, churning below the water’s surface, so keeping vital equipment dry…
(Peak Energy Blogspot)
The (UK) Telegraph has an article on the Vivace tidal / current power device I mentioned recently - Ocean currents can power the world, say scientists
The technology can generate electricity in water flowing at a rate of less than one knot - about one mile an hour - meaning it could operate on most waterways and sea beds around the globe.
Existing technologies which use water power, relying on the action of waves, tides or faster currents created by dams, are far more limited in where they can be used, and also cause greater obstructions when they are built in rivers or the sea. Turbines and water mills need an average current of five or six knots to operate efficiently, while most of the earth’s currents are slower than three knots.
The new device, which has been inspired by the way fish swim, consists of a system of cylinders positioned horizontal to the water flow and attached to springs.
As water flows past, the cylinder creates vortices, which push and pull the cylinder up and down. The mechanical energy in the vibrations is then converted into electricity.
Cylinders arranged over a cubic metre of the sea or river bed in a flow of three knots can produce 51 watts. This is more efficient than similar-sized turbines or wave generators, and the amount of power produced can increase sharply if the flow is faster or if more cylinders are added.
A “field” of cylinders built on the sea bed over a 1km by 1.5km area, and the height of a two-storey house, with a flow of just three knots, could generate enough power for around 100,000 homes. Just a few of the cylinders, stacked in a short ladder, could power an anchored ship or a lighthouse.
Systems could be sited on river beds or suspended in the ocean. The scientists behind the technology, which has been developed in research funded by the US government, say that generating power in this way would potentially cost only around 3.5p per kilowatt hour, compared to about 4.5p for wind energy and between 10p and 31p for solar power. They say the technology would require up to 50 times less ocean acreage than wave power generation.
The system, conceived by scientists at the University of Michigan, is called Vivace, or “vortex-induced vibrations for aquatic clean energy”.
Michael Bernitsas, a professor of naval architecture at the university, said it was based on the changes in water speed that are caused when a current flows past an obstruction. Eddies or vortices, formed in the water flow, can move objects up and down or left and right.
“This is a totally new method of extracting energy from water flow,” said Mr Bernitsas. “Fish curve their bodies to glide between the vortices shed by the bodies of the fish in front of them. Their muscle power alone could not propel them through the water at the speed they go, so they ride in each other’s wake.”
Such vibrations, which were first observed 500 years ago by Leonardo DaVinci in the form of “Aeolian Tones”, can cause damage to structures built in water, like docks and oil rigs. But Mr Bernitsas added: “We enhance the vibrations and harness this powerful and destructive force in nature.
“If we could harness 0.1 per cent of the energy in the ocean, we could support the energy needs of 15 billion people. In the English Channel, for example, there is a very strong current, so you produce a lot of power
(Posted by Big Gav on Tuesday, December 02, 2008 )