Wednesday, September 29, 2010

Thin films hold promise

This is not a blog dedicated to solar PV and if we have been covering more of this area, it is simply because there is so much technological advances happening here.

The concept of light-trapping has been played with for decades as a way of keeping a photon within the confines of a solar cell for longer periods of time, but there has always been upper limits of what energy the technique can wring from incoming light. By reducing the thickness of the cell to far less than the actual wavelength of light, though, appears to have a dramatic effect.

According to a paper published in Proceedings of the National Academy of Sciences, the ultrathin-film cells could improve on the macro-scale limits by as much as 12-fold.

By sandwiching the solar film between layers that act to keep light trapped for longer periods of time, chances that a photon will be absorbed are increased and increased significantly to boost efficiency. True, the technology is way off from commercial deployment, but it joins a growing array of new materials and methods that might soon dramatically increase solar power's potential.

Clean energy market on a high

The market for clean energy products is growing among India’s rural poor, a massive segment that consists of 114 million households and more than 60 percent of the nation’s population of 1.15 billion. Since 2004, this market has grown at an average rate of 36 percent a year and could eventually grow to more than $2.1 billion annually, according to a report from World Resources Institute.

Cean energy services and products will require an upfront investment three to ten times greater than that for conventional energy sources such as kerosene and firewood, which often are subsidized or free to India’s rural consumers. Yet despite these and other drawbacks, the average annual gross revenue of the companies profiled in this report has grown 36 percent since 2004.

The report examined a representative selection of companies selling solar lanterns, solar home systems, energy-efficient cookstoves, and electricity generated from decentralized sources, including small hydro power plants and biomass gasifier systems. The potential market for the four sectors studied in this report is INR 97.28 billion (US$2.11 billion) per year, including INR 94.06 billion (US$2.04 billion) for decentralized renewable energy services and INR 3.22 billion (US$70.1 million) for energy products per year.

Good news for the poor, corporates and the planet.

Scotland aims big

California took a big step in requiring that utilities must source 33 percent of their energy from renewables by 2020. Scotland has pushed the ceiling higher - it will be producing at least 100% of its electricity from renewable sources by 2025.

That was what its First Minister Alex Salmond declared recently. 'Scotland has unrivalled green energy resources and our new national target to generate 80% of electricity needs from renewables by 2020 will be exceeded by delivering current plans for wind, wave and tidal generation,” he says.

The predictions are based on an Offshore Valuation study, which estimates that by 2050 Scotland could be producing as much as 68 GW – or seven times its power needs – through offshore renewables.

By harnessing just a third of the region’s practical offshore wind and marine resources, Scotland could become a net exporter of clean energy. But enabling this transformation will be investment on a massive scale. The Offshore Wind Industry Group’s Route Map estimates that £200 billion in private finance will be necessary.

Now that is what we call leapfrogging, right?

Monday, September 27, 2010

Artificial leaves to make power

Any new technology always brings in fresh demand for metals or rare earth elements. Even solar technology with its reliance on silicon is not without its disadvantages. Perhaps when looking at alternatives, we also need to look at non-solid state technologies.

Like biologically inspired 'soft' devices for generating electricity! A team led by a North Carolina State University researcher has shown that water-gel-based solar devices -- "artificial leaves" -- can act like solar cells to produce electricity.

This can render the technology less expensive and more environmentally friendly than the current standard-bearer: silicon-based solar cells. The bendable devices are composed of water-based gel infused with light-sensitive molecules - the researchers used plant chlorophyll in one of the experiments - coupled with electrodes coated by carbon materials, such as carbon nanotubes or graphite.

The light-sensitive molecules get "excited" by the sun's rays to produce electricity, similar to plant molecules that get excited to synthesize sugars in order to grow.

Of course we cannot keep making leaves, hence why not look to how plants self-regenerate? And to look for something other than water-based gel and light-sensitive molecules to improve the efficiency of the solar cells.

Friday, September 24, 2010

New power saving technique

A new magnetic device being tested promises peak power saving of 39 percent. The device not only conserves electricity, but produces far less heat and produces less electromagnetic interference than conventional technologies.

Designed by the Tokyo Institute of Technology and fine-tuned by researchers at MERSTech in partnership with the ONR Global's office in Tokyo, the Magnetic Energy Recovery Switch (MERS) harnesses and recycles residual magnetic power that is produced by electrical current.

After working with several overhead fluorescent lights that require 24-hour power, scientists proved that the MERS technology significantly reduced lighting energy consumption.

Running out of fresh water

In the last few decades, the rate at which humans worldwide are pumping dry the vast underground stores of water that billions depend on has more than doubled. Not only are we running out of fresh water but also adding to sea-level rise!

In the new study, which compares estimates of groundwater added by rain and other sources to the amounts being removed for agriculture and other uses, the team taps a database of global groundwater information including maps of groundwater regions and water demand. The rate at which global groundwater stocks are shrinking has more than doubled between 1960 and 2000, increasing the amount lost from 126 to 283 cubic kilometers (30 to 68 cubic miles) of water per year.

The new assessment shows the highest rates of depletion in some of the world's major agricultural centers, including northwest India, northeastern China, northeast Pakistan, California's central valley, and the midwestern United States.

Today, people are drawing so much water from below that they are adding enough of it to the oceans (mainly by evaporation, then precipitation) to account for about 25 percent of the annual sea level rise across the planet, the researchers find. The team estimates the contribution of groundwater depletion to sea level rise to be 0.8 millimeters per year, which is about a quarter of the current total rate of sea level rise of 3.1 millimeters per year. That's about as much sea-level rise as caused by the melting of glaciers and icecaps outside of Greenland and Antarctica.

Groundwater represents about 30 percent of the available fresh water on the planet, with surface water accounting for only one percent. The rest of the potable, agriculture friendly supply is locked up in glaciers or the polar ice caps. This means that any reduction in the availability of groundwater supplies could have profound effects for a growing human population. Especially since we have no idea of how much groundwater exists!

Thursday, September 23, 2010

Let's go Uranium shopping!

All the world loves to hear of abundant fuel sources. And when an institution like MIT promises there is more than plenty of Uranium to run more than ten times the present number of 400 nuclear plants, everyone will want to go nuclear. Right?

The report, which comes in the backdrop of the US administration deliberations on whether to go full-scale nuclear or not, finds that uranium resources are not likely to run out in the next century, even if the U.S. alone builds as many as 1,000 nuclear reactors. Therefore, either reprocessing or recycling spent nuclear fuel, as the French and Japanese do, is likely to be a waste of money better spent on improving the light-water reactors presently in use.

Light water reactors are what the report calls attention to, with regard to improvisation while arguing against complicating the fuel cycle in considering alternate fissile fuels such as thorium. The M.I.T. report predicts that even if the world's fleet of more than 400 nuclear power plants grew to be 4,000 such plants that then operated for a century, the cost of the electricity from those facilities would rise by a mere 1 percent as a result of the increased demand for uranium.

Regarding spent fuel reprocessing, the report suggests a cycle involving light-water reactors, reprocessing of the spent fuel, and disposal of small "packages" of highly radioactive nuclear waste in deep boreholes. And to tackle proliferation, a leasing program, in which countries with the capability to enrich uranium fuel supply it to other countries and then take back the spent fuel for disposal in one form or another at the end of its useful life.

Fuel reprocessing like the kind it suggests have proved cost prohibitive, and the leasing issue has its own problems. The central issue still remains the 'abundance' of uranium and waste disposal from 4000 plants!

Decentralised solar

Orissa in India has decided to electrify approximately an additional 2,000 villages by March 2012. But instead of coal-fired power plants, it will be using decentralized solar power.

Biomass, wind power and a variety of small-scale hydropower projects are also in the mix. Further renewable energy development in Orissa includes 118 MW of biomass plants, with 20 MW of that to be completed soon. Two wind power projects, 150 MW in size are in the works, with surveys for 22 more locations underway. Micro, mini and small-scale hydropower projects are also planned for deliver an additional 300 MW.

Well, that's good news. Maybe this is the way forward for the thousand unelectrified villages. Grid connected energy will be difficult due to land use constraints as well as costs. In case of solar thermal, water use becomes a problem. But decentralised power avoids most of these issues.

Wednesday, September 22, 2010

To eat your food AND breathe clean air

The United Nations has called for universal access to modern energy services by 2030. At the same time, it has challenged the world to reduce energy intensity of 40 percent by that same year. If those two goals are met, the United Nations calculates, global emissions will increase by only 1.3 percent.

To help the United Nations expand access to modern energy for the 1.5 billion people who don't have it -- and do so in a way that doesn't cause the world's greenhouse gas emissions to skyrocket are a series of U.N. initiatives, including a new Global Alliance for Clean Cookstoves. The aim is to find cleaner alternatives for the roughly 3 billion people whom U.S. EPA estimate cook their food and heat their homes by burning coal, wood, animal dung or other materials.

According to the IEA, about 2.7 billion people -- about 40 percent of the global population -- still rely on the traditional use of biomass for cooking. Smoke from poorly ventilated cookstoves contributes to the early deaths of more than 2 million people a year, according to the U.N. Foundation.

There are basically three categories involved in bringing clean energy to those who currently have none: grid extension, where major institutions like the World Bank are helping; mini-grid systems, which have shown promise at the local village level, but also have high capital costs; and off-grid distributed generation. Many companies are also producing and distributing 2-watt solar-panel lanterns using LED lighting that last anywhere between four and 12 hours -- and also allow users to charge cell phones.

The UN's hope is to do for cookstoves and small-scale solar what happened with cell phones. Do you believe energy poverty will be tackled by 2030? DO write in.

Tech or policy?

Talk clean energy and one of the major difference of opinion comes when you talk of technology - is it already there? Again, is technology the silver bullet, or policy?

Current energy technologies are not enough to reduce carbon emissions to a level needed to lower the risks associated with climate change, New York University physicist Martin Hoffert concludes in an essay in the latest issue of the journal Science.

In order to avoid the risks brought about by climate change, steps must be taken to prevent the mean global temperature from rising by more than 2°C above pre-industrial levels. Current climate models indicate that achieving this goal will require limiting atmospheric carbon dioxide (CO2) concentrations to less than 450 parts per million (ppm), a level that implies substantial reductions in emissions from burning fossil fuels.

Current energy technologies are not sufficient to reduce carbon emissions to a level advocated by scientists. Energy sources, such as solar and wind electricity, are not adequate to achieve "massive market penetration," which requires utility-scale systems that can store intermittent supplies of power until they are needed. Two, reliance on carbon-emitting fuels is once again growing.

Broad investment will be crucial to enabling basic research findings to develop into applied commercial technologies. Carbon taxes and ramped-up government research budgets could help spur investments. But developing carbon-neutral technologies also requires, at the very least, reversing perverse incentives, such as existing global subsidies to fossil fuels that are estimated to be 12 times higher than those to renewable energy. That is something we have also been saying for some time now, as also most experts. Are there no listeners?

Solar PV on the rise



More on solar PV. Solar photovoltaic (PV) cell manufacturers produced a record 10,700 megawatts of PV cells globally in 2009—an impressive 51-percent increase from the year before. While growth in 2009 slowed from the remarkable 89-percent expansion in 2008, it continued the rapid rise of an industry that first reached 1,000 megawatts of production in 2004.

By the end of 2009, nearly 23,000 megawatts of PV had been installed worldwide. China produced 3,800 megawatts of PV in 2009, leading all countries for the second straight year.

Together China and third place Taiwan accounted for 49 percent of all PV manufacturing, a share that should keep climbing as companies there grow larger and more quickly than competitors based in countries where operating costs are higher.

Rounding out the top five producers in 2009 were Japan in second place, Germany in fourth, and the United States in fifth. These traditional industry leaders have lost significant market share with the recent ascent of China and Taiwan. Indeed, Japan, which dominated the global market in 2004, controls just 14 percent today.

On the installation side, Germany installed a record 3,800 megawatts of PV in 2009, more than half the 7,200 megawatts added worldwide. This brought Germany's overall PV generating capacity to 9,800 megawatts, nearly three times as much as the next closest country, Spain.

Organic solar cells have their uses

When it comes to solar technology, and solar PV in particular, you will most likely come across extreme opinions. Some who dismiss it as costly and inefficient, others who see hope in technology advances.

Yet it is true that solar cell tech is costly to mass-produce, especially at the scale we would require to replace fossil fuels. However,a great deal of international research is aimed at developing solar cells made up of organic (carbon-compound based) semiconductors. Although their performance is still considerably lower than that of cells based on crystalline silicon (around 5% efficiency as compared with 15% for silicon cells), they present numerous advantages. Unlike crystalline silicon, which has to be produced at very high temperatures, they can be manufactured cheaply with low energy cost and environmental impact.

To better understand the energy and environmental benefits and detriments of solar power, a research team from Rochester Institute of Technology has conducted one of the first life-cycle assessments of organic solar cells. The study found that the embodied energy -- or the total energy required to make a product -- is less for organic solar cells compared with conventional inorganic devices.

The study sought to calculate the total energy use and environmental impact of the material collection, fabrication, mass production and use of organic solar cells through a comprehensive life-cycle assessment of the technology.The team found that when compared to inorganic cells, the energy payback time for organic solar cells was lower.

Organic solar cells are not intended to compete with silicon, but rather to be used for specific applications, such as packaging, clothing, flexible screens, and recharging cell phones and laptops. In the longer term, they could make a significant contribution to the photovoltaic conversion of solar energy, if there is major investment in research into new, more efficient and stable materials. And that, the critics will say, is the crux of the issue - technology advances!

Monday, September 20, 2010

Clouded verdict

A new analysis of satellite data, collected over a decade, has identified the concentration, distribution, and composition of aerosol pollution over the Indian subcontinent. Using the multi-angle imaging spectroradiometer (MISR) from NASA’s Terra spacecraft, researchers at the University of Illinois at Urbana-Champaign, were able to document high levels of natural and human-caused pollution and reveal unexpected seasonal shifts in pollution.

Aerosol pollution across much of the country was two to five times higher than World Health Organization standards, with levels fluctuating during the seasons as monsoon rains wash away much of the smog and particulate matter, according to the study published in the Journal of Geophysical Research.

Black carbon particles, commonly called soot, are dark and light-absorbing and therefore warm the climate. Soot comes from combustion of fossil and biofuels, especially burning of diesel, coal and wood. Due to its warming effects, reduction of soot could help cool climate. However, soot absorption also affects cloud distributions and the verdict on how the clouds change is unclear. Because clouds mostly cool the climate, the possibility that soot absorption could increase cloud cover needs to be considered. And that means reducing BC may not be the silver bullet solution many thought.

Global model studies of soot effects on clouds do indeed find a variety of cloud responses, with increased clouds in some regions and decreased clouds in others. Most of the global model studies indicate that the net cloud response to absorbing particles is cooling. This suggests the need for caution when pursuing mitigation of soot in order to cool climate.

Sticker ups efficiency

A large transparent sticker applied to the front of a solar panel increases the power output by about 10% or so. These polymer films are imprinted with special kind of microstructures.

There are three main actions that are activated by these polymer films:
· Preventing light from reflecting off the solar panel surfaces.
· Trapping light to stay inside the semiconducting materials which absorb the light and then convert it into power.
· Redirecting the light that comes in so that the light will travel along the semiconductor material surface and not just pass through the material; this increases the likelihood of absorption of light more than before.

National Renewable Energy Laboratory results prove the fact that the films increase power output between 4-12.5% even when cloudy weather makes the light diffuse. Just adding the films increase cost of power generation by 1-10% but benefits far outweigh the cost, claims the lab. The question to be proved is the test of durability – which will be best answered by future.

Saturday, September 11, 2010

Peak coal by 2050

A new study suggests that the world is nearing the peak of readily exploitable reserves of high-quality coal, contradicting prevailing estimates that the globe has enough coal to help meet energy needs for at least a century. Tad Patzek, chairman of the Department of Petroleum and Geosystems Engineering at the University of Texas at Austin, said the world could be approaching the peak of coal mining and he predicts that by 2050 the global coal supply will be half what it is today.

Coal plants supply 40 percent of the world’s electricity. So if the prediction is right, we will see a real shake-up of the economy!

This study aside, chemical engineers at Newcastle University in Australia, the electrical engineer David Rutledge at the California Institute of Technology, and a German nonprofit called Energy Watch Group all have estimated that coal production would most likely peak in the next couple of decades. The Global Energy Systems group at Uppsala University (www.fysast.uu.se/ges) has also published a peer-reviewed paper in Fuel about Global Coal Production Outlooks predicting Peak Coal around 2040.

Peak coal around 2050 means that carbon emissions from global coal production would decline by 50 percent by 2050. That’s significantly below most of the carbon emissions scenarios produced by the Nobel Prize-winning Intergovernmental Panel on Climate Change. Patzek’s paper notes of IPCC scenarios, as being “based on economic and policy considerations that appear to be unconstrained by geophysics.”

Meanwhile forecasts for coal use point upward! The London-based World Coal Institute, an industry group including the largest international coal producers, says "the use of coal will rise 60 percent over the next 20 years," and that "coal will last us for at least 119 years." And the U.S. Energy Information Administration, in its most recent international outlook, projects that coal consumption for electricity will grow more than 50 percent by 2035 unless policies are put in place to stop the growth of greenhouse gas emissions.

It is going to take some more time and more studies for the world to believe in a peak coal. The general idea is that there's more of it underground.

Friday, September 10, 2010

The vanishing hum

Widespread reports of a decline in the population of bees and other flower-visiting animals have aroused fear and speculation that pollination is also likely on the decline. A recent University of Toronto study provides the first long-term evidence of a downward trend in pollination, while also pointing to climate change as a possible contributor.

One of the longest-term studies of pollination ever done, the study reveals a progressive decline in pollination over the years, with particularly noteworthy pollination deficits early in the season. The study will be published in Philosophical Transactions of the Royal Society B: Biological Sciences. What is particularly sobering is that it suggests that pollination is vulnerable even in a relatively pristine environment that is free of pesticides and human disturbance but still subject to climate change.

According to a previous study, England’s bees are vanishing faster than anywhere else in Europe, with more than half of hives dying out over the last 20 years.

Butterflies and other insects are also in decline due to habitat loss and climate change. It is estimated bees are responsible for one in three mouthfuls of food we take, and that insect pollinators contribute £440 million to the British economy through their role in fertilising crops. And that for a largely meat-eating nation.

Small pointers to what could become a big problem. After all, remember studying in school how important pollination is?

Thursday, September 9, 2010

Water solutions a click away?

Helping solve water crisis may take quite some time but a quick way to join in the efforts is to simply lend your computer time when idle.

Scientists will tap idle processing power to develop water filtering technology, clean up polluted waterways, and find treatments for water-related diseases.
Those were among the projects announced by IBM, which sponsors a global network of linked personal computers called the Worldwide Community Grid.

In China, Tsinghua University researchers, with the help of Australian and Swiss scientists, will use 1.5 million computers on the Worldwide Community Grid to develop nanotechnology to create drinkable water from polluted sources, as well as from saltwater.

To do that, the scientists need to run millions of computer simulations as part of their “Computing for Clean Water” project.

Brazilian scientists, meanwhile, will plug into the grid to screen 13 million chemical compounds in their search for a cure for schistosomiasis, a water-borne tropical disease that kills between 11,000 and 200,000 people annually.

In the United States, the Worldwide Community Grid will be used to run complex simulations that assess how actions by farmers, power plant operators, real estate developers, and others affect the health of Chesapeake Bay, the nation’s largest estuary.

Laudable effort even though one could say there are simpler ways to manage and conserve water! By simply becoming more conscious of this precious resource.

Tuesday, September 7, 2010

A million years old and still alive!

Here's a quick question for you: which is the world's oldest living being?

Chances are you would bank on the tortoise, but even the oldest known of these is only 175 years. We are talking in thousands of years! Quick!

How about something 400,000 to 600,000 years old? Yes, that is the age of the Siberian actinobacteria found in Copenhagen by researcher Rachel Sussman. And then there is the 100,000-year-old Posidonia Oceanica sea grass living off the coast of Ibiza! Or the Creosote bush found in Mojave desert of California which is 12,000 years old. The 13,000 year old underground forest of South Africa. And the 80,000 year old Aspen colony of Utah... for more of these ancients, check out TED.

What do these Ancients tell us besides the records of thousands of years? They speak of nature's resilience and adaptation to severe conditions. They also exhibit telltale symptoms of climate change induced scars. A stark reminder of how the human race stands to wipe out some of the planet's incredible life forms...

Freeze it, ship it & forget it

Storing and shipping natural gas by trapping it in ice--using technology being developed by researchers at the U.S. Department of Energy--could cut shipping costs for the fuel, making it easier for countries to buy natural gas from many different sources, and eventually leading to more stable supplies worldwide.

The technology traps natural gas in the form of methane hydrate, in which methane, the main component of natural gas, is confined within cage-like ice crystals.

Conventional technologies for making methane hydrate take hours or days: they involve mixing water and the hydrocarbon in large pressurized vessels. The new approach forces water and methane through a specially designed nozzle that creates the methane hydrate "almost instantaneously," says Charles Taylor, the lead researcher on the project at the DOE's National Energy Technology Laboratory in Pittsburgh. As the mixture exits the nozzle, it quickly forms hydrate, which looks like snow.

Making methane hydrate involves mimicking the high pressure and low temperatures at which it forms in nature, typically deep under the ocean. (Huge reserves of methane hydrate exist in places such as the Alaskan North Slope, both threatening to become another source of greenhouse gases and potentially offering a huge source of natural gas.)

Once the ice crystals form, they keep the methane confined even if the surrounding pressure is lowered, so the methane hydrate can be shipped at atmospheric pressure as long as it's kept frozen. The snow-like hydrate can be packed into cubes and loaded into the refrigerated ships, boxcars, and trucks now used to ship frozen food at -10 °C. That temperature is far easier and cheaper to manage than the -162 °C required for LNG. While the methane hydrate can burn, the methane is released slowly enough that it's not explosive.

Now that's smart thinking for you. Transport costs and leaks are among the major concern of gas supplies.

Monday, September 6, 2010

Holding on to vanishing water

Any guesses on the most critical problem facing humanity today? Yes, water scarcity. Already visible in pockets, this will spread to more parts and become the scourge of the civilisation.

An interesting book,Out of water: From abundance to scarcity authors look at practical ways to solve the issue. Storing water better will be one aspect. Be it big dams or ponds, tanks, small reservoirs and groundwater, a combination will be required.

The authors lay a six-point plan for overhauling water use to meet competing demands from agriculture, industry, cities and the environment. Our recommendations are that water planners: 1) gather high-quality data about water resources; 2) take better care of the environment; 3) reform how water resources are governed; 4) revitalize how water is used for farming; 5) better manage urban and municipal demands for water; and 6) involve marginalized people in water management.

Water management and understanding how climate change is affecting water availability will play important roles. We need to value the natural environment much more than we have in the past. (To phrase correctly, we need to value environment!)

With a third of the world’s inhabitants facing water scarcity, all sectors need to use water more efficiently. A good example that demonstrates how cities can do so is that of Sydney, where ‘water wise rules’ now restrict times at which gardens can be watered, ban sprinklers and only permit car washing at facilities that recycle water. New design principles are helping to reduce storm water runoff and increase the amount of water recycled, while a desalination plant is putting seawater to use. Meanwhile, industries are beginning to embrace the concept of ‘water footprinting’, where water use from ‘crop to shop’ is calculated to highlight where savings are possible.

How much has your city incorporated of such ideas?

Friday, September 3, 2010

Scrape to the last bit

They are truly rare and getting rarer by the day. About 124,000 metric tons of rare earth elements (REEs) were produced in 2009, with worldwide demand during this period estimated to be 134,000 metric tons — the difference have been made up from existing stockpiles. By 2012, worldwide demand is expected to reach 180,000 metric tons while mining operations are not expected to keep up with demand in the near term.

Rare earth elements are critical to a variety of high-tech products and manufacturing processes, including catalytic converters, petroleum refining, color TV and flat panel displays, permanent magnets, batteries for hybrid and electric vehicles, medical devices, and various defense systems like missiles, jet engines, and satellite components.

The Chinese produce 97% of REEs worldwide.

Rare earths are moderately abundant in the earth's crust, some even more abundant than copper, lead, gold, and platinum. While more abundant than many other minerals, REE are not concentrated enough to make them easily exploitable economically.

Either one has to look for alternatives which will take time, or stop using all those gadgets made from these elements (asking for the moon!) or simply pally up to China.

Or, recycle wherever possible, taking help from bacteria?

Researchers from the School of Biosciences at the University of Birmingham have found a way to use microbes, similar to the common soil bacterium Desulfovibrio desulfuricans, to recover palladium from useless industrial waste. Palladium itself is one of the most precious resource metals on Earth, boasting unique chemical properties. This metal can in fact be used as an active element in autocatalytic converters able to reduce greenhouse gas emissions.

As we have noted before, these are time of Peak everything!

Indestructible solar cells on way

If solar cells must get efficient in their job, they must be able to do pretty much whatever the plants (or leaves) do in converting the same sunlight into energy.For instance, repair themselves from exposure to sun! MIT researchers believe they are in on the secret.

Takinhg a cue from the self-assembly of chloroplasts the MIT team devised a novel set of self-assembling molecules that use photons to shake electrons loose in the form of electricity.

The system contains seven different compounds, including carbon nanotubes that provide structure and a means to conduct the electricity away from the cells, synthetic phospholipids that form discs that also provide structural support, and other molecules that self-assemble into "reaction centers" that actually interact with the incoming photons to release electrons.

These compounds can assemble themselves into structures able to harvest solar energy at an efficiency of about 40%. As they loose efficiency from damage, a surfacant can be spread across them to break down the compounds, then when it is filtered out, the cells reassemble good as new.

Seems too good to be true?

Thursday, September 2, 2010

Policies to drive energy efficiency

Whether it be about tackling climate change or energy crisis, the simplest and most obvious solution has simply not been pursued as earnestly as desired. And that is energy efficiency.

"Efficiency Works" a new report by Bracken Hendricks, Bill Campbell, and Pen Goodale, finds that a straightforward set of policies aimed at upgrading just 40 percent of the residential and commercial building stock in the United States would create 625,000 sustainable jobs, save 64 billion dollars and bring in large investments.

Some 10 key energy efficiency policies that states in the US are adopting or experimenting with to varying degrees are already providing examples of how policy-driven energy efficiency markets can create a new industry to power job creation, combat global warming and lower a nation's reliance on foreign fossil fuels.

Some of these are worth being considered by any country. For instance, policies that not only require utility companies to meet a set portion of demand from renewable energy but also include energy efficiency as a qualifying form of clean energy. And policies that establish markets for tradable clean energy credits and include energy efficiency as a qualifying clean energy resource.

Having specific standards that require utilities to plan for meeting a percentage of future growth in demand through energy efficiency instead of increasing supply; decouplingd utility rate structures, where utilities' rates are adjusted to compensate for changes in the volume of energy sold, removing the structural disincentive to conserve energy; penalties for noncompliance with energy efficiency standards, etc are some policies worth pursuing.

Any thoughts?

China faces dropping crop yields

Climate change could reduce key harvests in China by a fifth if the gloomiest scenarios prove true, according to a study published in Nature.

A team of Chinese scientists say China's climate "has clearly warmed" over the past half century, gaining 2.2 degrees F since 1960. "China experienced explosive economic growth in recent decades, but with only 7 percent of the world's arable land available to feed 20 percent of the world's population, China's economy may be vulnerable to climate change itself," the study warns.

In the most favorable scenario, grain yields by mid-century could remain stable or benefit from the rise in carbon dioxide levels. But in the worst scenario, there could be declines of 4 to 14 percent for rice, 2 and 20 percent for wheat, and 0 and 23 percent for corn in cases where these crops are rainfed rather than irrigated.

The biggest problem could be water stress, amplified by a growing and increasingly wealthy population.

While on water, another study notes that oceans are acidifying 10 times faster today than 55 million years ago when a mass extinction of marine species occurred. Much of the carbon dioxide pollution put into the air is absorbed by the world’s oceans.

Dissolved as carbonic acid, the pollution increases the acidity of the oceans, which is disrupting the marine food chain, especially by making it more difficult for plankton, corals, mollusks, and crustaceans to form their calciferous shells. To avoid substantial damage to ocean ecosystems, deep and rapid reductions of global CO2emissions by at least 50% by 2050, and much more thereafter are needed.

Sorry if we seem to be going on and on about climate change, but you can't well ignore the most pressing problem on the planet today!