Solar concentrators: Research on making solar power cheaper

A new research publication, launched less than a week after Earth Day, focuses on the impact of light engineering on the environment, green technologies and sustainable energy development. A bi-monthly supplement to Optics Express, the journal of the Optical Society, Energy Express will cover topics from making solar energy economical to providing energy from fusion.

The inaugural issue is dedicated to solar concentrators — a technology that harnesses the most abundant source of energy available to us: the sun. Solar concentrators aim to increase the efficiency of solar energy generation and the journal includes features on new devices that concentrate the sun’s rays and increase the efficiency of solar cells.

Despite its promise, solar power only accounted for about 1 percent of U.S. renewable energy production in 2008, according to the society. Because one of the greatest barriers to popularizing the use of solar power is its cost, industry experts are looking for ways to make its large-scale production cheaper.

How can solar energy become more affordable? By lowering the cost of solar cells or increasing the amount of power they generate, according to the Optical Society. Here are two of the methods, outlined by experts in Energy Express, which could achieve those goals:

Layered solar cell materials

The latest and most efficient solar cells in the National Renewable Energy Laboratory can achieve efficiencies greater than 40 percent while commercially-available solar panels are currently about 19 percent efficient. The best solar cells could reach 50 percent efficiency with more work, according to the laboratory’s Sarah Kurtz and John Geisz.

Solar fuels

Concentrated solar energy can be used to produce clean chemical fuels for the power and transportation sectors, according to Aldo Steinfeld of ETH Zurich and Alan Weimer from the University of Colorado. Thermochemical processes that make use of concentrated solar radiation as an energy source to drive high-temperature endothermic reactions have the potential to achieve high solar-to-fuel energy conversion efficiencies.

Image: False color image showing Earth’s solar energy absorption / NASA

 

A green light unto the nations

�I will make with you a covenant to be a light unto nations� Isaiah 42:6.

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Jews have long been identified as divinely selected to serve as a light unto nations. Democratic ideals, fidelity to justice, the rule of law and essential dignity of the human person are just a few examples of that model. Interestingly, so is the first known environmental protection exhortation -- to respect the planet and its resources. Specifically, the Torah commands �do not destroy trees by swinging an axe against them, for from them you will eat.� Deuteronomy 20:19.

Israel has been associated with environmental conscientiousness since the creation of the modern state 62 years ago. Around the world, awareness has also expanded as we consume resources, particularly fossil fuels, at alarming rates. Last week, the world celebrated its 40th �Earth Day� and, while some scientists may debate global warming, the felicitous objective of enjoying a greener planet is universally agreed upon. Moreover, major geopolitical factors have also entered the equation as much of the world�s oil and natural gas reserves are controlled by rulers hostile to the values described above.

Western civilization and the price of oil

Today, oil trades around $80 a barrel. This is more than double what it cost at the end of 2008, yet only about half of the high reached six months prior in July 2008. Clearly, oil is a volatile commodity. Tragically, it is also one that the world has become addicted to. I submit that the more important figure is the price of the last barrel of oil. Carried to the extreme, that price is binary: the last barrel will cost either $0 or $infinity. If we approach the latter price, we will concomitantly approach the end of western civilization. Therefore, we must dedicate massive resources to reach the former price, where oil becomes the oleaginous, messy, valueless liquid that it was before the industrial revolution.

Who will lead that effort? In response to the energy crisis generated by the Arab embargo in 1973 (following the Yom Kippur war), it looked like America along with Israel - would blaze that trail. Israel was a natural pioneer for this research. Passive solar home design, blocking/capturing heat during the day and releasing it at night, was embraced by Israeli architects as early as the 1970s and over 50% of domestic hot water has been produced by solar energy since the 1950s.

In fact, by the 1980s, Luz, an Israeli-American company was generating 95% of the world�s solar energy. Their first project was a 12.5 MW electricity-generating power station at Dagget, California, followed by six 30 MW power plants, employing a larger size solar collector unit. Ultimately, Luz erected two 80 MW power stations using even larger solar collector units. All of these plants are still operational, over 20 years later.

But in the mid-1980s oil became cheap again. Saudi Arabia increased the flow and the Reagan administration applauded the initiative. The US knew that the world�s second largest oil exporter was the Soviet Union and that low oil prices would cripple its economy. Mired in Afghanistan (America�s turn would come a quarter century later) and stretched thin to support failed satellite dictatorships around the world, the USSR relied heavily on its oil export revenues. As prices crumbled, so too did the Berlin Wall and, ultimately, the entire �Evil Empire.�

Thus the West won the Cold War, sometimes referred to World War III. Can it use a similar strategy to win World War IV, currently being waged against radical Islam financed by petro-dollars? I believe we can. But the Saudis won�t be our allies this time, nor will any other entity whose economy is fueled chiefly by oil exports. Today, the only way to make oil cheap is to make it useless.

The president�s recent drilling compromise received a lot of attention. In my view, it is a side-show. Even if America succeeds in increasing its share of the planet�s proven reserves from 3% to 4, 5 or even 10% (which is extremely unlikely), that�s a proverbial drop in the barrel as the US continues to consume 25% of the world�s production. Drilling may delay the inevitable, but it doesn�t eliminate the addiction. A heroin addict that plants poppies in his backyard is still an addict. Moreover, few addicts ever act in ways that alienate their dealers, which in our world are the dreadful oil exporters. Therefore, the only responsible rationale for increased drilling is to buy more time to develop alternative energy solutions.

Clearly, China understands that. It is busy securing oil drilling concessions from countries across Africa and Latin America and has surpassed the US as the chief importer of oil from Saudi Arabia. Yet, simultaneously, China is also investing massively in green technologies. The country is now the world�s largest manufacturer of photovoltaic solar panels and at the vanguard of developing a domestic electric car industry. Warren Buffet believes one company, BYD, knows what it takes to make China a �better place� and last year invested $230 million for a 10% stake in the company. Perhaps Buffet thinks Wang Chuan-Fu, BYD�s founder and chairman, means Shai Agassi in Mandarin.

Bright lights in Israel

These enterprises are critical if we are to reduce and, hopefully, eventually eliminate our dependence on oil. Better Place has already signed deals on five continents that want to move towards battery-powered electric cars. They also just raised another $350 million and progress has been impressive on all fronts. Additional cities, states and countries have clamored to be included and the company can�t handle even a fraction of the enthusiasm. According to Michael Granoff, Head of Oil Independence Policies for Better Place, �a critical question is how will the anticipated hunger for electricity be satisfied? We�re working closely with renewable energy companies, particularly in Israel, to ensure that Better Place�s success also inures to the benefit of companies expanding grid capacity with clean-tech solutions.�

Today, renewable sources like solar, wind, geothermal, biomass and hydro play a negligible role in the overall mix. However, the technologies are improving, especially abroad. While oil was cheap, US drivers paid less at the pump. Europeans did not. Most European countries taxed gasoline and, in my view, thus encouraged European companies to identify renewable energy solutions. Germany, Spain and the Nordic countries have been illuminating the path to non-oil dependent technologies and entire towns in Denmark are now powered by alternative energy sources.

Thankfully, Israeli companies are also playing a role. Luz went bankrupt in the 1990s, shortly after constructing the California plants, a victim of investment dollars run dry. However, Luz�s two major corporate successors remain leaders in concentrated solar power. Solel, which employs the next generation of Luz parabolic troughs for its solar thermal power plants was acquired last October by Siemens for $418 million. And BrightSource, founded by several former Luz engineers, just received $1.4 billion in US federal loan guarantees to construct three separate utility-scale solar thermal units in California that will generate 400 MW of electricity. That�s enough to power 140,000 homes and will nearly double the amount of solar thermal energy produced in the US today. According to Professor David Faiman of Ben Gurion University, �whoever invests in Israeli solar initiatives today is likely to be included in the next generation of soligarchs.�

US debt fuels Islamic militants

Let�s think about what the true price of oil is for America and the rest of the free world. If oil had no value, would we be grappling with the question of a nuclear Iran? Would Hamas, Hezbollah and other terror-based organizations be viable without any petro funding? Would the burgeoning number of Wahabi-financed hate-preaching madrasas continue to flourish? Would Al-Quaida even exist?

The United States has already spent over $1 trillion on the wars in Afghanistan and Iraq, and they�re likely to be there for a while. America imports about $300-500 billion a year in foreign oil and borrows over $2 billion every day to finance these expenditures. The national debt is over $12 trillion and rising. Unless our creditors all embrace the Koran�s prohibition against �riba,� the charging of interest on loans, America won�t get out of its economic jam until it gets out of its fossil fuel addiction. I believe that the West still has a green light. But we must hurry forward before it turns dark.

Lyon (Lenny) Roth is a senior executive at an international wealth management firm and a member of Ben Gurion University's Board of Governors.

Published by Globes [online], Israel business news - www.globes-online.com - on April 28, 2010

� Copyright of Globes Publisher Itonut (1983) Ltd. 2010

New nuclear plants for Iowa, California?

Developments in two US states could lead to the construction of new nuclear power plants. In Iowa, legislation has been passed to enable utilities to study building new power reactors, while in California Areva has firmed up its agreement to participate in a plant near Fresno.

 

The governor of Iowa has signed into law a measure which encourages utilities to conduct studies into the possible expansion of nuclear energy in the state. On 28 April, at the Des Moines offices of the International Brotherhood of Electrical Workers, Governor Chet Culver signed a bill which requires rate-regulated public utilities to undertake analyses of and preparation for the possible construction of nuclear power plants in Iowa.

 

The legislation calls for such studies to be conducted with only a limited cost to ratepayers and with the Iowa Utilities Board providing oversight. The bill also modifies existing law related to electricity generation and to switching existing coal-based plants to other fuel sources. Utilities will be able to enter into rate-making in order to pay for investments that may lead to lower carbon emissions from current plants. This, the governor said, "opens the door for plants to switch from coal to natural gas, add 'carbon capture' to existing plants, and add gas or biomass as a primary source of fuel for these plants."

 

On signing the bill, Culver commented: "This bill gives Iowa utilities and consumers more tools to make decisions on our energy future. The study will give us a clear idea of what the future for nuclear and alternative energies may hold in Iowa." He added, "From the $100 million Power Fund, to wind energy, to the Office of Energy Independence, we are building our own future in energy production, and the new energy economy can create good jobs with benefits for Iowans. We are proving that environmental protection and economic growth can and should be tied together."

 

In March 2010, the Iowa state Senate voted to allow utility MidAmerican Energy to increase electric consumer rates so that it can study the feasibility of constructing a nuclear power plant. A vote of 37-13 in favour has allowed a $4 per year increase in residential customers' electricity bills, with a $15 increase for commercial customers and $1100 for industrial customers. Over three years the additional funds, totalling $15 million, will be used by MidAmercian to finance a study into the feasibility of constructing a second nuclear power plant in the state.

 

MidAmerican had previously proposed constructing a nuclear power plant in Payette County, Idaho. However, in December 2007, it announced that it had decided not to proceed. At that time, the company said that its decision was "based on economic considerations and not on issues related to the suitability of the Idaho site."

 

There is currently only one nuclear power plant operating in Iowa: the single-unit Duane Arnold plant. The 600 MWe boiling water reactor (BWR) is majority owned and operated by NextEra Energy Resources (70%), while the Central Iowa Power Cooperative owns 20% and the Corn Belt Power Cooperative owns 10%. The reactor, which began operating in 1975, accounts for almost 10% of Iowa’s electricity generation, with the remainder primarily produced from coal-fired plants.

 

California dreaming

 

Meanwhile, in California - where a moratorium introduced in 1976 on new nuclear build is still in place - France's Areva has signed a memorandum of understanding (MoU) with Fresno Nuclear Energy Group (FNEG) to develop a "clean energy park" near Fresno. The MoU follows the signing a letter of intent to cooperate in December 2009. The park, in California's Central Valley, is eventually to include nuclear and renewable electricity generation.

 

Under the MoU, the two companies will work together on the site selection and initial development of a nominal 1600 MWe EPR reactor. The agreement also allows for the potential development of other Areva energy technologies, such as concentrated solar power.

 

In a statement, Areva and FNEG said that, once the site of the energy park has been selected, work will begin on the solar phase of the park.

 

Before a nuclear power plant can be built on the site of the park, the legislation banning the construction of such plants in California must first be removed. A bill to repeal this moratorium was voted down in April 2007, but may be reintroduced.

 

Researched and written

by World Nuclear News

 

Can the Sahara Light Up Europe with Solar Power?: Recent Developments in CSP

Across the world's sunbelts, concentrated solar power is emerging as a blindingly obvious answer both to global power – and local water – needs. But can it reach the scale required?

by Duncan Graham-Rowe

(A Desertec map of power from the Sahara to Europe. Source: Desertec Foundation)

Desertification is a dirty word, but deserts are not entirely without their uses. Plans are underway to transform swathes of the Sahara into a glimmering sea of mirrors, with the goal of piping cheap, clean and efficient solar energy into the heart of Europe.

Dubbed the Desertec Industrial Initiative, it will create vast fields of concentrated solar power (CSP) plants – arrays of mirrors which focus the sun's energy to turn water into steam, and so drive electrical turbines. From there, the power will flow through a network of low loss transmission cables to pipe electricity into the existing European grid, via Spain.

The £240 billion venture, which brings together such big energy names as Siemens and E.On, is designed to meet as much as 15% of Europe's fast-rising electricity demand by 2050. And the first electrons could be coming onstream in as little as five years' time…

This, says Jonathon Porritt, is something of a second coming for CSP. "It was first introduced after the oil shocks of the 70s and early 80s, but as soon as oil prices fell, all investment in that particular technology stopped."

But now that the cost of carbon is playing into the economics of energy production, CSP is looking increasingly promising. According to Keith Bowen, director of engineering at UK-based Circadian Solar, it holds two trump cards: efficiency and scale.

"It scales extremely well," he says. As the size of the plant increases, the relative costs come down. Large CSP plants can produce power for a quarter of the cost of that generated by standard solar photovoltaics, adds Bowen.

Efficiency is improving rapidly, too. Twenty years ago, the maximum efficiency you could get from the sun was 15-20%, compared with over 50% for fossil fuels. "Today," says Bowen, "[CSP is] closer to 40%."

And for those who live in or near deserts, that means it can also play a role in securing another vital asset: water. CSP is ideally suited to powering desalination plants. Taking salt out of water is a simple enough process, but one that uses a lot of energy. For developing countries where power shortages are a growing problem, as well as luxury resort islands where resources are scarce, Bowen argues, CSP could be an ideal solution – producing clean water and power at the same time.

A common criticism directed at both solar and wind power is that they're inherently intermittent: the sun only shines in the day, the breeze doesn't always blow. But recent advances in CSP could keep the power flowing all night long. Desertec is designed to operate 24 hours a day by superheating water to temperatures of 260ºC, sufficient to create steam at high enough pressures that it will keep driving turbines and generating electricity long after the sun has set.

An alternative approach, which is being explored by Solar Reserve in California, is to use the thermal energy to melt salt. Molten salt retains heat long enough to drive a turbine for much of the night. The company is hoping to build a 150MW solar plant in the Sonaran Desert, which would use 17,500 mirrors, each 24 meters wide, to heat salt to 565ºC. This would be enough to store up to seven hours of the sun's energy.

There's a lot of promise in this sort of approach, says Bowen. "It's been around for a while and is fairly well developed." But, he says, like other forms of CSP, it tends to work best on a grand scale, typically plants of 50MW or above.

Another development that should also help to spur CSP is the availability of better solar maps. These are detailed layouts of the earth's surface that show historical information about the amount of sunlight different locations receive. These data sheets have long been available from places like the US Government's National Renewable Energy Laboratory in Colorado, quantifying typical solar trends in different geographic regions. Now companies like 3TIER in Seattle, Washington, are making it possible to target locations for solar power not just by general region but at much higher resolutions. This enables prospective CSP developers to zero in on ideal sites.

3TIER's maps are the first to take into account not just solar activity but also the impact of long-term and seasonal wind variations. These can be significant between locations just a few kilometers apart, and affect the energy required to continually readjust the position of the mirrors.

Using this sort of approach, it has become possible to choose sites that will optimize energy output, says Gerry Wolff, Coordinator of DESERTEC-UK, an independent advisory group of CSP enthusiasts. In fact, he says, it's been calculated that a single patch of the Sahara, just 114,090 square kilometers in area, receives enough sunlight to meet the entire world's electricity demands through CSP.

So what's stopping us? Partly cost, says Wolff. Hovering at around 10-20 US cents per kilowatt hour, CSP "looks a little bit on the expensive side," compared with gas at about 5 cents. But this is likely to change when the volumes increase, he says. Indeed, three studies carried out by the German aerospace industry suggest that CSP could eventually become one of the cheapest sources of electricity in Europe. "Until about 2017, electricity from CSP will probably be more expensive," concludes Wolff. But then, as economies of scale kick in, it will become cheaper and increasingly attractive.

It is certainly attracting growing interest. The World Bank recently announced it is investing $5.5 billion into the development of CSP across North Africa. And last year, Morocco, the only North African state with no oil production of its own, declared its intention to become a pioneer in CSP as a way of cutting reliance on oil and gas imports. It plans to build five plants with a total energy production of 2,000MW by 2020.

In light of such investment, the Desertec Industrial Initiative seems less of a leap of faith. The technology to transmit the electricity across the vast distances to Europe has been well established for decades, says Wolff. But realistically, it only needs to reach as far as Spain, since Europe already has an international electrical transmission grid. This, Wolff adds, acts a bit like a pond, in the sense that it doesn't matter where you fill it up from. "So countries as far north as Sweden would immediately benefit."

The consensus on CSP now, says Jonathon Porritt, is that although it's extremely ambitious, it's also quite realistic. Besides the potential to generate vast amounts of electricity, the growing need for renewable sources of desalinated water makes CSP an excellent candidate for support, he says.

The irony is that in years to come we may find ourselves looking to deserts not just for power, but also for water.

Solar, Lighter

CSP may be a simple idea, but it doesn't come cheap. It's not easy building in the middle of a desert, and there are fairly substantial costs involved in constructing all the mirrors and central receiver towers, which have to withstand extreme temperatures and continuously pump water up to the collector. One solution to this is to dispense with the steam turbines and instead concentrate the light on highly efficient photovoltaic solar cells – the approach taken by Circadian.

Another novel approach, under experimentation at the Tokyo Institute of Technology, is to construct cheaper lightweight towers, containing a second set of mirrors at the light collection point. These are used to redirect the light to heat water at ground level, precluding the need to pump it up the tower.

This piece originally appeared in The Guardian.

Want to learn more? Look into the Worldchanging archives:
Clean Power From Deserts
Concentrated Solar Power Goes Mainstream: Lockheed-Martin To Build Large CSP Plant With Thermal Storage In Arizona
eSolar Launches First Solar Tower in US
World’s Second* Largest Solar Plant To Be Built in Florida

European wind energy continued its surging success By Chris Rose

European wind energy continued its surging success By Chris Rose 27 de abril de 2010

Annual EWEA statistics show how well the wind power industry and other renewables are growing while some more traditional sectors are in retreat.

Despite the worst recession in more than 65 years, the continued growth of wind power last year sparked such a bright light for the vitally important European energy portfolio that it can only be described as phenomenal.

Data compiled by EWEA and other sources shows that wind power installations accounted for a staggering 39% of new electricity-generating capacity in 2009. By way of comparison, wind’s share of newly installed capacity a year earlier increased 35%.

The 10,163 MW of EU wind power capacity installed last year represents a 23% increase over 2008. It is also the second year in a row that more wind energy was installed in the EU than any other generating technology.

Wind power’s future continued to glow brightly on a number of other fronts. The wind capacity installed by the end of 2009 will in a normal year produce 163 TWh of electricity, meeting 4.8% of total EU power demand. According to the latest figure from Eurostat, final electricity consumption in the EU-27 was 3,372 TWh in 2007.

Not surprisingly, most of the new wind power capacity (9,581 MW) was realised through onshore wind farm installations while the remainder (582 MW) was derived from new offshore facilities. The onshore increase was 21% greater than 2008’s while the new offshore wind farm installations jumped 56% compared to new installations the previous year.

The EWEA annual statistics also showed that EU wind power, though buffeted by exceedingly fragile money markets trying to ride out the severe economic downturn, still saw investments of €13 billion in wind farms in 2009, including €1.5 billion in the nascent offshore sector.

“This is a great result in a year that was far from easy,” said Christian Kjaer, EWEA Chief Executive. “The figures confirm that wind power, together with other renewable energy technologies and a shift from coal to gas, is delivering massive European carbon reductions, while creating much needed economic activity and new jobs for Europe’s citizens.”

After wind turbines, of all new EU electricity generating capacity installed last year in addition, 25% or 6,630 MW came from gas while 17% or 4,600 MW was from solar photovoltaics. In addition, 2,406 MW (9%) of new coal was installed, 581 MW (2.2%) of biomass, 573 MW (2.2%) of fuel oil, 442 MW (1.7%) of waste, 439 MW (1.7%) of nuclear, 338 MW (1.3%) of large hydro, 120 MW (0.46%) of concentrating solar power, 55 MW (0.2%) of small hydro, 12 MW (0.04%) of other gas, 3.9 MW (0.01%) of geothermal, and 405 kW of ocean power.

Together, renewable energy technologies accounted for 62% of new European power-generating capacity in 2009, marking the second year in a row that renewable energies have accounted for the majority of new installations.

The EWEA report indicates that each year since 2008 renewable electricity generating technologies have accounted for more than 50% of new power installations – mostly wind power, but also solar PV, hydro power, and biomass.

This trend has increased from just 14% of new installations in 1995, to the 61% last year. The data reveals that the power sector in Europe is still moving away from coal, fuel oil and nuclear, as each of those power technologies continued decommissioning inefficient plants. For example, the coal sector decommissioned 3,200 MW, the nuclear sector decommissioned 1,393 MW, and the fuel oil sector decommissioned 472 MW.

In all, the EU’s total installed power capacity increased last year 20,150 MW, to 820,606 MW, with wind power increasing its share of installed capacity to 74,767 MW (9.1%), up from 64,719 MW by the end of 2008.

Additionally, the data shows that annual installations of wind power have increased steadily over the last 15 years from 472 MW in 1994 to the 10,163 MW in 2009, an annual average market growth of 23%.

Overall, the statistics show that Germany remains the EU country with the largest total of installed capacity at 25,777 MW, followed by Spain (19,149 MW), Italy (4,850 MW), France (4,492 MW), and the UK (4,051 MW).

Yet the nations with largest share of new capacity installed in 2009 were Spain (24% or 2,459 MW), followed by Germany (19% or 1,917 MW), Italy (11% or 1,114 MW), France (11% or 1,088 MW) and the UK (10% or 1,077 MW).

While Europe’s wind energy installations last year continued to be dominated by development in its mature markets, it is worth noting that Portugal (7% of new installations or 673 MW), Sweden (5% or 512 MW), Denmark (3% or 334 MW), and Ireland (2% or 233 MW) also performed strongly.

New power installations last year continued the trend in changes in EU net installed capacity for the various electricity generating technologies from 2000 to 2009. The net growth of natural gas (81 GW) and wind power (65.1 GW) came about at the expense of fuel oil (down 12.9 GW), coal (down 12 GW) and nuclear power (down 7.2 GW).

Jacopo Moccia, who compiles EWEA statistics, said there were several reasons that wind power did so well in the EU last year despite the ongoing economic downturn. “Wind power is a proven technology,” Moccia said. “Furthermore it is clean, has short lead times and no fluctuating fuel costs. If you add to that the strong political support for renewables in the EU, it is clearly seen as a safe investment with good potential returns. It is the ideal investment to ride through a crisis.”

An EWEA regulatory affairs advisor, Moccia said that offshore wind, although still smaller in terms of onshore installations, had a very good year in 2009 and should expect an even better future. “Offshore has started taking off as an industry in and of itself, and it should
no longer been seen as an extension of onshore wind. Over the past years many countries, especially around the North Sea, have been laying the foundations for offshore wind farm development via ambitious policies,” he said.

“We are now beginning to reap what has been sown, and forecasts for next year and beyond are even more exciting. We should expect offshore to keep growing at high rates, until by the second half of the 2020s the offshore industry should become bigger than the onshore one.”

He also said the €13 billion in EU wind farm investments last year demonstrate how wind energy is an ideal industry to re-launch Europe’s growth. “Wind is bringing in investments and creating jobs whilst helping us to meet the energy and climate crises we face that could, in the future, cause Europe even greater fi nancial woes than those we are living today.”

Moccia, who described wind power as the power technology of choice, was asked why EU wind saw the largest growth of all generating technologies for the second year in a row, and what that accomplishment says about the old, more traditional energy technologies such as coal and oil.

“Today’s energy mix is the result of technologies developed in the past. These technologies are not suited for the socio-economic and environmental challenges we are facing. This year 61% of all new electricity generating capacity was renewable, up from just 14% in 1995. We can truly talk of the de-carbonisation of Europe’s energy mix, which also augurs well for Europe’s future energy independence.”

He also said that the continuing success of wind power can help policy makers working towards promoting emissions free technologies and agreeing on a new and strengthened post-Kyoto pact to reduce greenhouse gas emissions caused by burning fossil fuels.

“Today, wind turbines produce almost 5% of the EU’s electricity. By 2020 we expect them to meet up to 17% -- the equivalent of 131 million average EU households and avoiding 333 million tonnes of CO2 annually. By 2030, wind energy could be meeting up to 35% of the EU’s electricity needs, equivalent to 241 million households and avoiding 600 million tonnes of CO2 annually. I think these fi gures speak for themselves.”

By Chris Rose, www.ewea.org/fileadmin/emag/winddirections/2010-04/

Inaugural issue of OSA's Energy Express focuses on gaining energy with solar ...

Inaugural issue of OSA's Energy Express focuses on gaining energy with solar concentrators

WASHINGTON, April 26�New devices that concentrate the sun's rays, increase the efficiency of solar cells, and help to lower the cost of solar energy, are featured in the inaugural issue of Energy Express, a new special bi-monthly supplement to Optics Express, the open-access journal of the Optical Society (OSA). Edited by Bernard Kippelen of the Georgia Institute of Technology, Energy Express launches today and will focus on research that encompasses the science and engineering of light and its impact on sustainable energy development, the environment, and green technologies. Research featured in Energy Express will highlight the role optics plays in energy efficiency and sustainability, from making solar energy economical to providing energy from fusion, to studying new combustion processes that can ease carbon dioxide sequestration, to monitoring the nitrogen cycle, and to realizing significant energy savings using solid-state lighting, such as inorganic and organic light emitting diodes (LEDs and OLEDs).

To underscore the importance of optics in energy, Energy Express will publish a series of Focus Issues dedicated to selected research areas. The first issue of Energy Express is a special Focus Issue dedicated to new developments in solar concentrators, a set of technologies that aim to increase the efficiency of the generation of solar energy. Roland Winston of the University of California Merced is the guest editor for this issue.

Solar concentrators hold great promise for delivering plentiful alternative energy and contributing to the world's energy needs in the future, since direct sunlight is by far the most abundant source of energy available on Earth. But while the basic technology behind solar panels has been around for decades, solar power still only contributes a tiny amount to the overall power consumed each year in the United States, for example. In 2008, it accounted for roughly 1 percent of U.S. renewable energy production, with all renewable sources together contributing only approximately 7 percent of the total amount of energy produced in the U.S. that year�the latest for which statistics are available from the U.S. Energy Information Administration.

One of the barriers to the widespread use of solar power in the U.S. is its cost. Currently, it is still significantly more expensive dollar-per-watt than power generated by burning coal, oil, or natural gas. If solar power generation is going to increase in the future, large-scale production will have to become cheaper�perhaps by either lowering the cost of solar cells or increasing the amount of power they generate.

Several articles featured in the inaugural issue of Energy Express focus on the latest emerging new technologies that aim to achieve this. These include new materials and designs for solar cells that can increase their efficiency; new approaches to concentrating the sun's rays to allow solar panels to make the most of the daylight; and applications of solar power that harness the sun's energy to remove the salt from seawater, generate chemical fuels, and power solid-state lighting.

Some highlights of the special Focus Issue on Solar Concentrators include:

LAYERED SOLAR CELL MATERIALS

One of the basic approaches to improving solar panels in the last several years has centered on increasing their efficiency�the amount of the sun's energy hitting the panels that they can convert into useable electricity. The greater the efficiency of a solar cell, the more energy it can produce when in the sun.

Commercially available flat-plate solar panels are currently around 19 percent efficient, but in the last several years, scientists have been able to do significantly better by making "multijunction cells." These stack several layers of ultra-thin materials on top of each other. Each separate layer absorbs a particular range of colors (or wavelengths) of light, and together they convert a broader spectrum of the sun's energy into electricity.

According to Sarah Kurtz and John Geisz of the U.S. National Renewable Energy Laboratory, the latest, most efficient cells in the laboratory can achieve efficiencies greater than 40 percent. In their Energy Express paper, they predict that this cutting edge will continue to move, and the best solar cells may reach 45 or 50 percent efficiency with further work.

The article, "Multijunction solar cells for conversion of concentrated sunlight to electricity" by Sarah Kurtz and John Geisz can be accessed at: http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-18-S1-A73.

CONCENTRATING LIGHT WITH LENSES AND SUN TRACKING

While multijunction solar cells can achieve higher efficiencies, their thin layers may rely on rare and expensive elements like indium and gallium in their design, and the cells themselves often must be constructed under exacting laboratory conditions. These factors make the best solar cells very expensive to produce.

One way to counter these costs is to increase the amount of energy the cells produce by concentrating the sunlight that falls on them. In one Energy Express paper, Valery Rumyantsev and colleagues at the Ioffe Physical Technical Institute in St. Petersburg, Russia describe such ways to maximize the amount of energy from solar cells by squeezing as much sunlight as they possibly can into them.

The Ioffe team is combining cells with Fresnel lenses�optical elements similar to the sort of shaped glass that allows lighthouse torches or theatrical spotlights to focus light into a strong beam. They also use sun-tracking devices to automatically orient solar panels with the direction of the sun as it moves across the sky.

In another paper, Roland Winston and Weiya Zhang of the University of California Merced describe a non-tracking solar concentrator that does not rely upon precise sun-tracking devices, which may add to the cost and complexity of installing and maintaining solar panels, they observe, and which may not be practical on residential rooftops.

Winston and Zhang have developed a stationary solar concentrator that concentrates sunlight up to four times for eight hours a day, year-round. This has the potential to reduce the number of expensive solar cells in a solar panel by four, they say.

The article, "Solar concentrator modules with silicone-on-glass Fresnel lens panels and multijunction cells" by Valery D. Rumyantsev can be accessed at: http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-18-S1-A17.

The article, "Pushing concentration of stationary solar concentrators to the limit" by Roland Winston and Weiya Zhang can be accessed at: http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-18-S1-A64.

IMPROVED DYES FOR CONCENTRATING SOLAR ENERGY

Marc Baldo and colleagues at the Massachusetts Institute of Technology report the latest research on another way to eke out more power from solar panels. They use an inexpensive technology known as luminescent solar concentrators to increase the usable energy falling from the sun onto solar cells.

These concentrators consist of glass or plastic sheets coated by a thin film of dye molecules. The dye absorbs specific colors of sunlight and then re-emits light at longer wavelengths that gets trapped within the glass and converted into electricity by small solar cells attached to the edges of the concentrator.

These concentrators are inexpensive and are a potential solution for lowering the cost of solar electricity, Baldo and colleagues say. In their paper, they are reporting a significant new improvement they achieved by suspending the dye molecules in a liquid crystal and controlling their orientation. In their article, they report the highest light trapping efficiency by a luminescent solar concentrator to date.

The article, "Dye Alignment in Luminescent Solar Concentrators: I. Vertical Alignment for Improved Waveguide Coupling" by C.L Mulder, P.D. Reusswig, A. M. Vel�zquez, H. Kim, C. Rotschild, M.A. Baldo can be accessed at: http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-18-S1-A79.

SOLAR FUELS

In their Energy Express paper, Aldo Steinfeld of ETH Zurich in Switzerland and Alan Weimer from the University of Colorado at Boulder review how concentrated solar energy can be used to produce clean chemical fuels for the power and transportation sectors. Thermochemical processes that make use of concentrated solar radiation as an energy source to drive high-temperature endothermic reactions have the potential to achieve high solar-to-fuel energy conversion efficiencies.

They describe solar thermochemical cycles to split H2O and CO2 via metal oxide redox reactions. They also describe solar processes and reactors in which coal, for instance, can be converted into high-quality synthesis gas (mainly H2 and CO), which can be further processed to Fischer-Tropsch liquid fuels with a solar-upgraded calorific value and, consequently, lower CO2 emissions per kWh. Ultimately, these solar-driven processes provide means of storing intermittent solar energy in a transportable and dispatchable chemical form.

The article, "Thermochemical Production of Fuels with Concentrated Solar Energy" by Aldo Steinfeld and Alan W. Weimer can be accessed at: http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-18-S1-A100.

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ABOUT ENERGY EXPRESS

As a special bi-monthly supplement to Optics Express, Energy Express is dedicated to rapidly communicating new developments in optics for sustainable energy. Energy Express will have original research side-by-side with review articles written by the world's leading experts in the science and engineering of light and its impact on sustainable energy development, the environment, and green technologies. For more information, see: http://www.OpticsInfoBase.org/ee.

ABOUT OSA

Uniting more than 106,000 professionals from 134 countries, the Optical Society (OSA) brings together the global optics community through its programs and initiatives. Since 1916 OSA has worked to advance the common interests of the field, providing educational resources to the scientists, engineers and business leaders who work in the field by promoting the science of light and the advanced technologies made possible by optics and photonics. OSA publications, events, technical groups and programs foster optics knowledge and scientific collaboration among all those with an interest in optics and photonics. For more information, visit www.osa.org.

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North Africa Finally Sees the Light

CAIRO, Apr 27 (IPS) - Europe's appetite for renewable energy and a shifting tide in domestic energy policies could turn North Africa into major exporter of solar power by the end of the decade."North Africa has all the right ingredients for producing the cheapest kilowatt hour of solar energy," says Amr Mohsen, CEO of Lotus Solar Technologies, a Cairo-based solar technology firm. "We're finally starting to see conditions align for harnessing this potential." Small projects using photovoltaic (PV) panels are moving ahead rapidly, but work has been slow on large concentrated solar power (CSP) projects that experts say are needed to overcome the region's dependence on fossil fuels. CSP projects use mirrors to concentrate the sun's heat, and produce steam that drives electrical generators. The technology is scalable and without the high capital costs associated with large-scale PV deployment. The first CSP projects in North Africa are expected to begin operation by the end of the year. Algeria's 150 MW power plant at Hassi R'Mel is scheduled to go online in October, followed by Egypt's 140 MW plant at Kureimat and Morocco's 450 MW plant at Ain Beni Mathar. The three integrated solar combined cycle (ISCC) power stations will feed steam generated by a solar field into the stream of a gas-fired plant to drive a turbine that produces electricity. The hybrid design was selected because the shared turbine and equipment lowers capital costs, while the gas-fired unit compensates for fluctuating power output from the solar arrays, which generate electricity only during daylight hours. Critics charge that the low solar fraction -- between four and 15 percent -- undermines the value of these projects as commercial models. Officials counter that successful operation will pave the way for larger, dedicated solar plants to follow. "Our (ISCC) plant at Kureimat is a pilot project," says Khaled Fikry, head of research and development at Egypt's National Renewable Energy Authority. "We will gain technical experience that we will use to build more power plants that utilise pure solar capacity." Sunny skies and large tracts of underutilised desert land make North Africa an ideal location for low-cost power generation, a 2007 study by the German Aerospace Centre concluded. Harnessing the solar energy falling on just 6,000 square kilometres of desert in North Africa would "supply energy equivalent to the entire oil production of the Middle East of 9 billion barrels a year," the report said. European investors have cued in to the region's untapped potential. Two ambitious schemes envision the construction of a series of solar fields in the Sahara desert that would export surplus electricity to Europe via high voltage transmission lines. The Desertec project is a 400 billion euro private sector initiative that aims to tap renewable energy sources in North Africa to satisfy 15 percent of Europe's electricity demand by 2050. Up to 80 percent of the electricity generated, mostly by CSP power stations, would be used by domestic consumers. The remaining 20 percent would be transported to buyers in Europe. The Mediterranean Solar Plan, a flagship project of the Union for the Mediterranean (a union of European countries with others that border the Mediterranean Sea) follows a similar model. The project will invest over 40 billion euros to build solar facilities and purchase their output to help Europe achieve its goal of 20 percent renewable energy use by 2020. "A lot of momentum has been added through the activities of these initiatives," says Kilian Baelz, an expert in renewable energy finance. "They have really made North African governments think again about how to implement renewable energies." Tunisia launched a 2.7 billion dollar scheme in October 2009 that is targeting a 22 percent reduction in the country's demand for conventional energy sources by 2016. The Tunisian Solar Plan funds over 40 renewable energy projects and introduces subsidies on solar panels. Morocco, which imports 97 percent of its fossil fuel needs, recently unveiled a 9 billion dollar project to produce 2 GW of solar power by 2020. Five solar power stations will generate nearly 40 percent of the country's total installed power. North African governments are also looking to dismantle oil and gas subsidies that have undermined the adoption of renewable energies. "Subsidising fossil fuels is putting a very high burden on the finances of these countries," says Hani El-Nokraschy, vice-chairman of Desertec's supervisory board. "Even if they are self-producers of oil or gas, they have the chance to generate the electricity they need from the sun and sell the fuel they would have burned on the world market for a higher profit." He estimates that with subsidies removed, CSP has already achieved grid parity. While benchmark Brent crude oil stands at about 85 dollars a barrel and is expected to rise in the coming years, economies of scale are driving down the cost of solar power. "The price of electricity from CSP power stations is equal to the price of electricity of burning oil at 50 dollars per barrel," El-Nokraschy tells IPS. "And by doubling production you would get a 10-20 percent cost reduction." Governments cannot afford to wait. El-Nokraschy says North Africa must install at least 100 GW of exportable renewable energy capacity by 2050 to reduce Europe's greenhouse gas emissions. Failure to do so would -- if predictions about global warming are correct -- result in a plus 2.0 degree Celsius rise in global temperature, leading to severe weather and a rise in sea levels. "This would be catastrophic and would cost us much more than the price of building enough CSP to prevent it," he adds. (END/2010)