Saturday, September 26, 2009

Impacts of Climate Change coming faster and sooner.


The pace and scale of climate change may now be outstripping even the most sobering predictions of the last report of the Intergovernmental Panel of Climate Change (IPCC).

An analysis of the very latest, peer-reviewed science indicates that many predictions at the upper end of the IPCC's forecasts are becoming ever more likely.

Meanwhile, the newly emerging science points to some events thought likely to occur in longer-term time horizons, as already happening or set to happen far sooner than had previously been thought.

Researchers have become increasingly concerned about ocean acidification linked with the absorption of carbon dioxide in seawater and the impact on shellfish and coral reefs.

Water that can corrode a shell-making substance called aragonite is already welling up along the California coast?decades earlier than existing models predict.

Losses from glaciers, ice-sheets and the Polar Regions appear to be happening faster than anticipated, with the Greenland ice sheet, for example, recently seeing melting some 60 percent higher than the previous record of 1998.

Some scientists are now warning that sea levels could rise by up to two metres by 2100 and five to ten times that over following centuries.

There is also growing concern among some scientists that thresholds or tipping points may now be reached in a matter of years or a few decades including dramatic changes to the Indian sub-continent's monsoon, the Sahara and West Africa monsoons, and climate systems affecting a critical ecosystem like the Amazon rainforest.

The report also underlines concern by scientists that the planet is now committed to some damaging and irreversible impacts as a result of the greenhouse gases already in the atmosphere.

Losses of tropical and temperate mountain glaciers affecting perhaps 20 percent to 25 percent of the human population in terms of drinking water, irrigation and hydro-power.

Shifts in the hydrological cycle resulting in the disappearance of regional climates with related losses of ecosystems, species and the spread of drylands northwards and southwards away from the equator.

Recent science suggests that it may still be possible to avoid the most catastrophic impacts of climate change. However, this will only happen if there is immediate, cohesive and decisive action to both cut emissions and assist vulnerable countries adapt.

These are among the findings of a report released today by the United Nations Environment Programme (UNEP) entitled Climate Change Science Compendium 2009.

The report, compiled in association with scientists around the world, comes with less than 80 days to go to the crucial UN climate convention meeting in Copenhagen, Denmark.

In a foreword to the document, the United Nations Secretary-General, Ban Ki-moon, who this week hosted heads of state in New York, writes, "This Climate Change Science Compendium is a wake-up call. The time for hesitation is over".

"We need the world to realize, once and for all, that the time to act is now and we must work together to address this monumental challenge. This is the moral challenge of our generation."

The Compendium reviews some 400 major scientific contributions to our understanding of Earth Systems and climate change that have been released through peer-reviewed literature, or from research institutions, over the last three years.

Achim Steiner, UN Under-Secretary General and UNEP Executive Director, said, "The Compendium can never replace the painstaking rigour of an IPCC process?a shining example of how the United Nations can provide a path to consensus among the sometimes differing views of more than 190 nations".

"However, scientific knowledge on climate change and forecasting of the likely impacts has been advancing rapidly since the landmark 2007 IPCC report," he added.

"Many governments have asked to be kept abreast of the latest findings. I am sure that this report fulfils that request and will inform ministers' decisions when they meet in the Danish capital in only a few weeks time," said Mr. Steiner.

The research findings and observations in the Compendium are divided into five categories: Earth Systems, Ice, Oceans, Ecosystems and Management. Key developments documented since the IPCC Fourth Assessment Report include:

Earth Systems

A new climate modeling system, forecasting average temperatures over a decade by combining natural variation with the impacts of human-induced climate change, projects that at least half of the 10 years following 2009 will exceed the warmest year currently on record. This is despite the fact that natural variation will partially offset the warming "signal" from greenhouse gas emissions.

The growth in carbon dioxide emissions from energy and industry has exceeded even the most fossil-fuel intensive scenario developed by the IPCC at the end of the 1990s. Global emissions were growing by 1.1 percent each year from 1990-1999 and this accelerated to 3.5 percent per year from 2000-2007.

The developing and least-developed economies, 80 percent of the world's population, accounted for 73 percent of the global growth of emissions in 2004. However, they contributed only 41 percent of total emissions, and just 23 percent of cumulative emissions since 1750.

Growth of the global economy in the early 2000s and an increase in its carbon intensity (emissions per unit of growth), combined with a decrease in the capacity of ecosystems on land and the oceans to act as carbon "sinks", have led to a rapid increase in the concentrations of carbon dioxide in the atmosphere. This has contributed to sooner-than-expected impacts including faster sea-level rise, ocean acidification, melting Arctic sea ice, warming of polar land masses, freshening of ocean currents and shifts in the circulation patterns of the oceans and atmosphere.

The observed increase in greenhouse gas concentrations are raising concern among some scientists that warming of between 1.4 and 4.3 degrees Centigrade above pre-industrial surface temperatures could occur. This exceeds the range of between 1 and 3 degrees perceived as the threshold for many "tipping points", including the end of summer Arctic sea ice, and the eventual melting of Himalayan glaciers and the Greenland ice sheet.

Ice

The melting of mountain glaciers appears to be accelerating, threatening the livelihoods of one fifth or more of the population who depend on glacier ice and seasonal snow for their water supply. For 30 reference glaciers in nine mountain ranges tracked by the World Glacier Monitoring Service, the mean rate of loss since 2000 has roughly doubled since the rate during the previous two decades. Current trends suggest that most glaciers will disappear from the Pyrenees by 2050 and from the mountains of tropical Africa by 2030.
In 2007, summer sea ice in the Arctic Ocean shrank to its smallest extent ever, 24 percent less than the previous record in 2005, and 34 percent less than the average minimum extent in the period 1970-2000. In 2008, the minimum ice extent was 9 percent greater than in 2007, but still the second lowest on record.
Until the summer of 2007, most models projected an ice-free September for the Arctic Ocean towards the end of the current century. Reconsideration based on current trends has led to speculation that this could occur as soon as 2030.

Melting of the Greenland Ice Sheet surface also seems to be accelerating. In the summer of 2007, the rate of melting was some 60 percent higher than the previous record in 1998.

The loss of ice from West Antarctica is estimated to have increased by 60 per cent in the decade to 2006, and by 140 percent from the Antarctic Peninsula in the same period.

Recent findings show that warming extends well to the south of the Antarctic Peninsula, to cover most of West Antarctica, an area of warming much larger than previously reported.

The hole in the ozone layer has had a cooling effect on Antarctica, and is partly responsible for masking expected warming on the continent. Recovery of stratospheric ozone, thanks to the phasing out of ozone-depleting substances, is projected to increase Antarctic temperatures in coming decades.

Oceans

Recent estimates of the combined impact of melting land-ice and thermal expansion of the oceans suggest a plausible average sea level rise of between 0.8 and 2.0 metres above the 1990 level by 2100. This compares with a projected rise of between 18 and 59 centimetres in the last IPCC report, which did not include an estimate of large-scale changes in ice-melt rates, due to lack of consensus.

Oceans are becoming more acidic more quickly than expected, jeopardizing the ability of shellfish and corals to form their external skeletons. Water that can corrode a shell-making carbonate substance called aragonite is already welling up during the summer along the California coast, decades earlier than models predict.

Ecosystems

Since the 2007 IPCC report, wide-ranging surveys have shown changes to the seasonal behaviour and distribution of all well-studied marine, freshwater and terrestrial groups of plants and animals. Polar and mountaintop species have seen severe contractions of their ranges.
A recent study projecting the impacts of climate change on the pattern of marine biodiversity suggests dramatic changes to come. Ecosystems in sub-polar waters, the tropics and semi-enclosed seas are predicted to suffer numerous extinctions by 2050, while the Arctic and Southern Oceans will experience severe species invasions. Marine ecosystems as a whole may see a species turnover of up to 60 percent.

Under the IPCC scenario that most closely matches current trends ? i.e. with the highest projected emissions ? between 12 and 39 percent of the Earth's land surface could experience previously unknown climate conditions by 2100. A similar proportion, between 10 and 48 percent, will see existing climates disappear. Many of these "disappearing climates" coincide with biodiversity hotspots, and with the added problem of fragmented habitats and physical obstructions to migration, it is feared many species will struggle to adapt to the new conditions.
Perennial drought conditions have already been observed in South-eastern Australia and South-western North America. Projections suggest that persistent water scarcity will increase in a number of regions in coming years, including southern and northern Africa, the Mediterranean, much of the Middle East, a broad band in Central Asia and the Indian subcontinent.

Management

The reality of a rapidly-changing climate may make conventional approaches to conservation and restoration of habitats ineffective. Drastic measures such as large-scale translocation or assisted colonization of species may need to be considered.
Eco-agriculture, in which landscapes are managed to sustain a range of ecosystem services, including food production, may need to replace the current segregation of land use between conservation and production. This could help create resilient agricultural ecosystems better able to adapt to the changing climate conditions.

Experts increasingly agree that active protection of tropical forests is a cost-effective means of cutting global emissions. An international mechanism of reducing emissions from deforestation and forest degradation (REDD) is likely to emerge as a central component of a new agreement in Copenhagen. However, many issues need to be resolved, such as how to verify the reductions and ensuring fair treatment of local and indigenous forest communities.

A number of innovative approaches are emerging to keep carbon out of the atmosphere, including the use of "biochar", biologically-derived charcoal. It is mixed in soils, increasing fertility and potentially locking up carbon for centuries. This is a 21st century application of a technology known as Terra Preta, or Black Earth, used by Amazon peoples before the arrival of Europeans in South America.


Ref: IPCC Website

Friday, September 25, 2009

UN conference on Global Warming - Was it successful?


On 22nd September 2009, government leaders representing about 100 nations gathered at the United Nations in New York to discuss global warming. The meeting was billed as an attempt to jump-start negotiations in advance of a December summit in Copenhagen at which a global treaty governing greenhouse gas emissions is to be produced.

Instead, the New York conference only served to highlight the impossibility of realizing even the most limited environmental reforms in a world order dominated by rival capitalist nation states.

Global warming is caused by carbon dioxide emissions created in the burning of fossil fuels. Carbon and other “greenhouse gases” trap heat in the atmosphere, increasing the earth’s temperature beyond normal climatological fluctuations. Among global warming’s observed effects are the melting of the polar ice caps, which threatens coastal populations due to rising sea levels, and an increase in the severity of weather patterns. Its impact on the earth’s species, food production, water supply and human disease will be dramatic.

In light of the gathering threat of environmental catastrophe, the inability of the world heads of state to agree on even modest measures to meet it is all the more glaring. The conference revealed sharp divisions among the world’s three largest greenhouse gas producers, the US, China, and Europe.

China and the US by themselves produce 40 percent of all carbon emissions. The two nations, whose economies are also tightly bound together, have refused to agree to mandates on emission reductions. The speeches of presidents Barack Obama and Hu Jintao, both of whom addressed the UN gathering, were therefore watched with particular interest.

Obama’s remarks were typical of the president. The speech had nothing to say about what the US might do to reduce its emissions.

“Yes, the developed nations that caused much of the damage to our climate over the last century still have a responsibility to lead,” Obama said. “And we will continue to do so by investing in renewable energy, promoting greater efficiency, and slashing our emissions to reach the targets we set for 2020 and our long-term goal for 2050.”

In fact, the US has taken no significant measures to reduce its carbon emissions. The US is not a signatory to the Kyoto Protocol of 1997, after Congress, on cue from major corporate polluters, refused to ratify the treaty. The US is the only major country not to pass Kyoto.

Obama did not use his UN speech to call on the the US Senate to produce a greenhouse gas emissions bill in advance of the Copenhagen meeting. To be ratified, any treaty would require a 67-vote Senate majority.

Obama favors a “free market” solution to global warming, or so-called “cap and trade” measures, which would provide rich incentives to corporations to modestly reduce carbon emissions, while turning pollution into a tradeable commodity. Such a bill was passed in the House in June, but has been held up in the Senate until some time next year. (See "US House passes Obama administration’s carbon trading legislation".)

The only difference that Obama’s speech enunciated from the previous American position was an acceptance that global warming is, in fact, taking place and that it is caused by human activity. This Obama referred to as an “historic recognition on behalf of the American people and their government [that] we understand the gravity of the climate threat...” George W. Bush, Obama’s obscurantist predecessor in the White House, notoriously declared that “all the science isn’t in yet” on global warming.

Yet, in his speech’s only substantive portion, Obama reiterated the Bush administration position that combating carbon emissions is the responsibility of developing industrial powers like China and India. “Those rapidly-growing developing nations that will produce nearly all the growth in global carbon emissions in the decades ahead must do their part as well,” Obama said.

Given that China and India are rapidly growing economies, it is unsurprising that their carbon emissions are also growing rapidly. But they still lag far behind the US in per capita carbon production. While the US produces about the same amount of carbon as China, it has less than a fourth of China’s population.

There is little doubt that China’s rapid industrial expansion is creating an environmental disaster. Much of China’s energy consumption comes from burning coal, which produces carbon emissions at a higher rate than other fossil fuels.

Hu tacitly rejected the American president’s claim that developing countries must shoulder the burden for reducing carbon emissions. “Developing countries need to strike a balance between economic growth, social development and environmental protection,” Hu said.

Hu indicated that China would continue to increase its carbon emissions, saying only that greenhouse gas output would decrease relative to economic growth. Hu also said that China would begin a large-scale reforestation project, increase its consumption of non-fossil fuels, and develop a “green economy.”

The French president, Nicolas Sarkozy, addressed the meeting on behalf of the European nations, which “have grown increasingly frustrated with Mr. Obama for not investing more political capital in the climate agenda at home,” the British daily Telegraph notes.

Sarkozy used his speech to take a swipe at Obama, telling the gathered heads of state he would not “inflict” a “grandiose speech” on delegates when “concrete proposals” are required.

Sub-Saharan African and poor island nations, which are already suffering under the effects of global warming and which produce relatively negligible amounts of carbon, are requesting financial reparations from the wealthier nations primarily responsible for global warming.

The French environment minister, Jean-Louis Borloo, went out of his way to reject such a proposal. “They have to show what it will pay for,” he said.

It is clear that if any agreement is produced at December’s Copenhagen gathering, it will be a derisory response to the crisis of global warming.

To date, major industrialized nations have agreed to reduce emissions by 2050. This date is so far in the future, and the promises to reduce emissions so vague, that it is not taken seriously. The United Nations’ Intergovernmental Panel on Climate Change has proposed a short-term target of reducing emissions by 25 percent to 40 percent below 1990 levels by 2020. This reduction, which environmental groups say is insufficient to reverse global warming, is likely to be opposed by the US as well as China and India, which reject emission mandates.

There are also unresolved disagreements over what body should oversee compliance with carbon emission standards.

Ban Ki-Moon, the UN secretary general, who called the climate change summit, lamented that “negotiations were moving as fast as a glacier.”

Slower, perhaps, than the world’s glaciers are melting.

Wednesday, September 16, 2009

Indian wind energy could cover 24% of the country’s power needs by 2030


Honorable Minister for New and Renewable Energy, Govt. of India, Dr. Farooq Abdullah released a book titled “Indian Wind Energy Outlook 2009" on the 9th September 2009 in New Delhi. This report is published jointly by the Global Wind Energy Council (GWEC) and Indian Wind Turbine Manufacturers Association (IWTMA).

The study examines the potential of wind power in India up to the year 2030 and found that the technology, re-powering, untapped off-shore potential and furthering wind resource assessment could play a key part in the nation’s effort to provide energy to its ever growing demand in an economy which will boom and at the same time combat climate change.

“India is already an established force in the global wind energy markets, and yet, it has the potential to achieve so much more,” said GWEC Secretary General Steve Sawyer. “Wind energy can be deployed at a very large scale in a very short period of time. With the right support, it can make a major difference in improving India’s energy independence by providing it with vast amounts of clean, indigenous energy.”

The report explains how wind energy can provide up to 24% of the India’s power needs by 2030 while attracting 475 bn Rs in investment every year and creating 213,000 ‘green collar’ jobs in manufacturing, project development, installation, operation, maintenance, consulting etc. At the same time, it would save a total of 5.5 bn tons of CO2 in that timeframe.

The ‘Indian Wind Energy Outlook’ explores three different scenarios for wind power – a Reference scenario based on figures from the International Energy Agency (IEA); a Moderate version which assumes that current policy measures and targets for renewable energy are met; and an Advanced Scenario which assumes that all policy options in favour of renewables have been adopted. These are then set against two demand projections for electricity demand.

Mr. D V Giri, Chairman, IWTMA, said, “In our rapidly growing economy, the security of energy supply is key and wind energy potential must not be wasted. Deploying wind energy at a large scale would help us to realize significant economic and environmental benefits. We now urge the government to fast track proposals to introduce a National renewable energy policy to help the industry to make this happen for India. He also added, “IWTMA plays a significant role as turnkey solution providers with ‘state of the art’ technology to its customers.”

Mr. Arthouros Zervos, Chairman, GWEC, said, “This report demonstrates that wind technology is not a dream for the future – it is working now, and ready for tackling India’s energy challenges.” He also added, “The political choices of the coming years will determine the world’s and India’s, environmental and economic situation for many decades to come. The wind industry stands ready to do its part in what the UN Secretary General has described as ‘the defining struggle of the 21st century’. With sufficient political will and the right frameworks, it could do even more”.

To date, 10 Indian states have implemented supporting policies for wind energy. The Ministry of New and Renewable Energy (MNRE) is currently considering plans to introduce Generation Based Incentive (GBI) which is expected to attract Foreign Director Investment (FDIs) and Independent Power Producers (IPPs).

The report is part of a wind industry campaign entitled ‘Wind Power Works’, which is coordinated by GWEC and supported by IWMTA. Its aim is to increase government awareness and positive action on wind energy in the run up to the COP 15 climate talks in Copenhagen in December 2009.

Monday, September 14, 2009

Prospects of CPV Technology


Concentrating PV employs optic elements to concentrate sunlight on to cells which are much more efficient and smaller than conventional cells. These optic elements allow the concentration of sunlight, multiplying its intensity by factors that range from 2, in low concentration, to more than 1000, in high concentration. Given that the efficiency of CPV cells tends to increase with concentration, CPV can afford to reduce the use of semi-conductive material used in cells without lowering the overall efficiency of the system.

Currently, most CPV companies employ triple junction cells. Mass produced multi-junction cells have reported efficiencies of 35% to 39%, which exceed the efficiency of conventional silicon cells by a wide margin. The combination of high efficiency cells with optic elements allows CPV to produce the same amount of energy whilst using 1775 times less cell surface than standard PV systems . Given that the semiconductor materials that make up the cells are the most expensive, this should result in a reduction in the cost per kWh.

Despite its potential for staggering cost reductions, CPV is still relatively costly. According to a CPV today report , the costs of CPV are around 0.31 to 0.39 € per kWh. These high prices are partly due to the small scale of most CPV installations. However, dramatic cost reductions are expected in the coming years, bringing CPV within an affordable cost bracket of 0.12 to 0.15 € per kWh in 2015 in places with a level of solar irradiation of 2500 kWh/m2/year.

Increases in cell efficiency and optic elements will be crucial factors in bringing about these cost reductions. It is expected that in 2015 triple junction cells will reach record efficiencies of 50% while optics systems could reach between 80% and 90%.

WHAT IS CPV

Concentrator PV systems convert sunlight directly to electricity, just as other photovoltaic technologies do, but with some important differences. First, CPV systems use different PV cell technology. CPV systems utilize high-efficiency, multi-junction cells, not silicon. These cells provide over twice the conversion efficiencies of most silicon cells—approaching 40+%. Thus, the amount of photovoltaic material used is a fraction of that used in traditional PV systems.

Second, CPV systems use optical elements — mirrors or lenses — to collect and focus sunlight onto these high-efficiency cells. In the optical system shown in the figure at the top of the page, the primary mirror collects the sunlight, focuses it on the secondary mirror, then it travels down the optical rod, concentrating it 650 times onto the high efficiency cell. Similar to a telescope, the CPV optics are trained on the sun’s position and collect and concentrate light onto the solar cell.

Third, CPV systems incorporated precision, dual-axis tracking to keep the concentrators in alignment with the sun throughout the day. By tracking the sun from sunrise to sunset, CPV systems produce energy at a steady rate throughout the day and power production remains at high levels during afternoon’s peak demand hours.

By replacing expensive PV material with comparatively inexpensive optics, utilizing high efficiency PV cells, and tracking the sun, energy generation potential is much higher and cost of energy much lower than with other solar technologies in the high solar resource regions of the world.

CPV technology has clearly moved out of the lab and prototyping phase -- becoming a reality with multi-megawatt installations underway. Today we are faced with dramatically increasing electricity demand globally presenting a critical need for clean, renewable energy. While the sun is the world's most abundant renewable resource, today it is barely tapped as an energy source. The challenge has been in cost effective conversion of that sunlight to electricity. Historically, harvesting photons has been hindered by high costs compared with traditional energy.

Photovoltaics technology (PV) has played a critical role in the evolution of renewable energy. The important thing to recognize, however, is that for the PV industry to reach its growth potential and become a major source of the world’s energy supply, then technology cannot stand still. Technologies like silicon PV and thin films must continue to evolve, working to squeeze more energy out of PV cells, and driving to lower cost. But that alone won’t take us far enough. There is a need for disruptive technologies that leverage existing technology, but are more advanced at providing benefits not achievable with current technologies.

EMERGING CPV

CPV is a young technology but the progress made in the past three years alone has been dramatic. In this short time, the number of companies developing CPV systems has grown from a handful to three dozen. The number of companies advancing technology for high-efficiency cells is accelerating, and commercial deployments have gone from a few kilowatts of primarily test sites, to somewhere around 5–8 MW in 2008. The expected deployments this year are forecasted to be between 30–50 MW. CPV now has a place under the sun.

GEOGRAPHICAL SUITABILITY

In areas where the solar resource is high, CPV systems are ideal, including such areas as southern Europe, the southwest U.S., Africa, Australia, parts of Latin America and Asia. We estimate that CPV is ideally suited to about one-third of the world’s land regions, which represent ~40% of the world’s population. In these regions, CPV technology will provide the highest level of energy production and the lowest cost of electricity.

HIGHEST EFFICIENCY LEVELS

CPV has been challenged by some as being too expensive a technology. There are two key factors to understand related to cost. First is efficiency. The single biggest impact on the cost of delivering solar energy is efficiency of the system — in other words, the rate at which the system can convert sunlight to electricity. CPV clearly has the highest efficiency levels — nearly twice that of most PV. Of equal importance is the fact that these efficiency levels are increasing on a steady upward trajectory, with tremendous headroom before they begin to approach any theoretical limits for the cell technology.

The second factor is the issue of manufacturing costs. From a volume manufacturing perspective, CPV is in its infancy. The manufacturing cost reduction curve, resulting from rapidly increasing volumes combined with automation, is also moving at a very steep trajectory downward. When you combine the increasing efficiency and decreasing manufacturing costs, CPV clearly leads the industry in its cost of energy reduction potential.

CPV-SUITABLE FOR BIG SOLAR POWER PLANTS

From a scalability standpoint, there are two key factors to understand. First, CPV systems use very little specialized PV material. The majority of the system is built from readily available materials that can be sourced globally including aluminum and glass. The materials supply shortages that have plagued the solar industry in the past are much less of an issue for CPV, allowing for very rapid scalability from a materials perspective.

CPV also has a much lower cap-ex requirement than other solar technologies. This is a very important element of rapidly building capacity as the deployment of CPV systems moves from 8 MW to 50 MW to gigawatts of capacity in the not-so-distant future. CPV provides deployment flexibility from small sites to large utility-scale power plants, with projects being deployed for commercial, industrial, and utility customers in both on-grid and off-grid environments.

CPV SPECIALITIES

High-temperature performance

While it would be easy to assume that high solar resource regions are ideal for all solar, that is not the case. When it gets hot, silicon PV and thin films both suffer temperature degradation, resulting in a much lower energy production as temperature rises. On the contrary, the multi-junction cells used in CPV systems do not suffer from significant temperature degradation. Energy producers get the highest energy output per megawatt installed with CPV. Higher energy production directly correlates to lower cost of energy.

Environmental sustainability

CPV uses significantly less PV material than traditional photovoltaics. It depends on the system, but in the case of SolFocus (Fig. 1), its systems are over 97% recyclable. Being mounted on trackers (Fig. 2), not directly on the ground, the systems do not disrupt the land as much as other technologies do. Dual-use of the land is possible; land could be improved while producing energy.

CPV also offers a much shorter energy payback than other solar technologies. While it varies depending on the system, energy payback is 6 months for reflective CPV technology like SolFocus’, compared to 2 years for traditional PV. Also important: CPV does not use water to produce electricity. In many high solar resource regions, water is in scarce supply. With technologies such as concentrating solar power, says a National Renewable Energy Laboratory (NREL) report, power plants consume on average 750–1000 gallons/MWh of energy production.

CONCLUSION

CPV solutions are changing the face of PV. Deployment of ground mounted, utility scale systems is growing. The cost of solar energy in the fastest growing solar markets is reducing rapidly. The environment is benefiting not just from clean energy, but from energy created with a very small carbon footprint. The technology has clearly moved out of the lab and prototyping phase, and is becoming a reality with multi-megawatt installations underway.
Ref: Article by Nancy Hart Soch




Saturday, September 05, 2009

Solar Power from Space


The idea of generating solar power from space has been gathering momentum for quite some time. And various alternative energy companies are investing substantial amount of money in this concept. The advantages of harnessing solar energy from space are many. Solar energy in space is ten times more than on the planet earth. In space there are no nights and no weather changes. The wear and tear will be less too because of lack of humidity, rain, storm or friction.
Mitsubishi Electric Corporation and IHI Corporation are undertaking an ambitious project of $ 21bn. They are aspiring to design and develop a Space-based solar farm that would generate 1GW of power. This will require an area of four square kilometer consisting of rows of solar panels. This space solar farm will be housed 36,000km above the surface of the earth.

This 21bn power project has a timeline of three decades. Before wetting their feet fully, Japan Aerospace Exploration Agency (JAXA) will go for a small 10MW demonstration satellite which would have solar panels. This smaller project would be completed in 2015. This experimental project will first test the water before taking the whole plunge. They will also test the systems used to beam energy from space to ground-based receivers. Once fully developed the plant will generate about 1GW of solar power on the ground. It could be a base load resource instead of an intermittent source of power. This amount of power can meet the energy needs of about 294,000 Tokyo homes on an average.

In fact base load issues are one the last hurdles when we talk about many forms of renewable energy. But the million dollar question to tackle is how to get the power from the solar panels affixed upon the orbiting platforms back to Earth? Currently the existing knowledge says that one can convert it into radio frequency energy for transmission. We can install a receiving station on the earth, which then converts it back into electricity.

If successful, the pilot project could deal with certain concerns such as the use of environmentally sensitive areas for extensive solar farms. However, they have to tackle one more issue: the energy required to produce and put these solar panels into space versus the amount of energy they may generate. One of the solutions can be that they can utilize the concept of space elevators.

A division of JAXA, the Institute of Space and Astronautical Science (ISAS) has already prepared a prototype of the SPS2000, a 10 megawatt demonstration solar-power satellite.

ISAS is also undertaking a project where an experimental satellite will be tested for wireless power supply of several hundred kilowatts. Ground experiments are being held for scrutinizing the influence of high-voltage discharge which is a sheer necessity for large-capacity power generation in space. They are also spending time on the impact of space debris on the solar farm.


Ref: Mitsubishi Electric Corporation

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