Estuary power

A team of researchers from Stanford University recently announced that estuaries around the globe could provide 13% of the world’s energy needs. An estuary is where a river meets the sea, and the team believes that these areas where fresh water and salt water converge could be tapped as a renewable energy goldmine. Whenever river water diffuses into salty seawater there is a slight rise in temperature – this energy could theoretically be captured and harnessed to create electricity.

Traditional systems utilize osmotic power, where salt water draws fresh water through a membrane, causing an increase in pressure. This pressure then turns a turbine to produce electricity — but the Stanford team is working on a new method. As reported by the Royal Society of Chemists, the Stanford team has developed a system that uses a battery to draw energy through a crystal lattice made of manganese dioxide nanorods. This enables a large surface area to be packed into a small space, creating the potential to generate large amounts of energy.

The system would also enable salt to be gathered so it can be converted into molten salt, which we all know can be used in power plants, wastewater treatment, energy generation and hydrogen gas production.

Well, every bit helps!

Needed safe technologies

Now that it is official that radiation from Fukushima reactors have leaked into the ocean, fresh fears have been triggered. How will this affect the food chain, especially for those who consuming fish? Nothing much to fear say experts. But anyone willing to take a chance?

Meanwhile, more nuclear proponents are coming out saying that nuclear is the safest bet! You bet. For instance, there is the UK's former chief scientist David King who sees nuclear as far less dangerous than coal plants. Hydro is no less dangerous, some say.

One of the chief arguments is the balance of energy demand and supply. Can renewables step up significantly from the 5 percent or so they comprise? Storage needs apart, they require storage which is still a challenge.

The real issue for the world, according to some analysts, is the “energy-spent” versus the “energy-paid-back”. The “energy-spent” includes the energy needed to grow or find the resources (like ore or vegetation), mine or harvest the resources, refine the resources, transport the resources, build the energy sources, maintain the energy sources (like windmills or solar facilities), and refurbish or remove the sources after their nominal life.

These calculations have not been done for any of the new technologies and without it, there is not much of a change in the scanario. It will be coal, gas and nuclear that will meet the kind of demand that is constantly on the rise. Perhaps, all we can do for now is to make these technologies safer and cleaner. Easier said than done? What do you think?

Taking a leaf from nature

Solar energy has its share of critics and proponents and they will debate for hours on why and why not solar is a green energy. But there is no arguments that this is one source raining on the planet and it would be foolish to ignore it.

Perhaps a leaf could succeed where PVs have been struggling?

That is what the latest announcement from MIT indicates. They have developed an advanced solar cell the size of a poker card that mimics the process, called photosynthesis, that green plants use to convert sunlight and water into energy.
The team leader envisions "villages in India and Africa not long from now purchasing an affordable basic power system based on this technology."

About the shape of a poker card but thinner, the device is fashioned from silicon, electronics and catalysts, substances that accelerate chemical reactions that otherwise would not occur, or would run slowly. Placed in a single gallon of water in a bright sunlight, the device could produce enough electricity to supply a house in a developing country with electricity for a day.

It does so by splitting water into its two components, hydrogen and oxygen. The hydrogen and oxygen gases would be stored in a fuel cell, which uses those two materials to produce electricity, located either on top of the house or beside it.

The first artificial leaf was developed more than a decade ago by John Turner of the U.S. National Renewable Energy Laboratory in Boulder, Colorado. Although highly efficient at carrying out photosynthesis, Turner's device was impractical for wider use, as it was composed of rare, expensive metals and was highly unstable -- with a lifespan of barely one day. The new leaf overcomes these problems. It is made of inexpensive materials that are widely available, works under simple conditions and is highly stable.

So? a leaf or a PV cell?

For rain's sake

Recent climate modeling has shown that reducing the concentration of carbon dioxide in the atmosphere would give Earth a wetter climate in the short term. A new study shows that cutting carbon dioxide concentrations could help prevent droughts caused by global warming.

Carbon dioxide traps heat in the middle of the atmosphere. This warm air higher in the atmosphere tends to prevent the rising air motions that create thunderstorms and rainfall. As a result, an increase in the atmospheric concentration of carbon dioxide tends to suppress precipitation. Similarly, a decrease in the atmospheric concentration of carbon dioxide tends to increase precipitation.

The team's work shows that carbon dioxide rapidly affects the structure of the atmosphere, causing quick changes precipitation, as well as many other aspects of Earth's climate, well before the greenhouse gas noticeably affects temperature.

Waste not waste

Schwarzenegger may be gone but California continues to trudge heavily on the green energy path. Now it is the turn of human waste to generate energy!

California produced 661,000 dry metric tons of biosolids in 2009, according to the energy commission. Referred to as 'biosolids', these can also include a sludge of heavy metals and other toxins left over from wastewater treatment. While in some cases biosolids can be used as fertilizer for crops, they most often have to be disposed of in landfills.

"Existing options for using biosolids are limited (mainly land application and alternative daily cover in landfills) and face increasing environmental challenges that could eliminate those options," the energy commission noted. "Current disposal practices often involve hauling biosolids long distances, which consumes transportation fuels, increases greenhouse gas emissions, and increases ratepayers' costs for wastewater treatment."

A company now plans to use "steam/carbon dioxide reforming" technology to vaporize liquid residues and gasify the organic solid portion of biosolids in an airlock chamber. The company will pump in steam and carbon dioxide to create a hydrogen-rich gas that could be used in fuel cells to generate electricity.

This is a new experiment, worth watching! Plenty of source material everywhere.

Make your choice

As the debate over conventional and renewable energy picks up, in the wake of the Japan disaster it makes sense to look at safe options. People tend to forget the deaths associated with coal mining, as also that fly ash produced by a coal-burning power plant “carries into the surrounding environment 100 times more radiation than a nuclear power plant producing the same amount of energy.” (Scientific American)

Not to forget spills, the latest one in north Atlantic spells sure death to 20,000 penguins!

Solar and wind also have their share of accidents, too. Silane (a key chemical for solar cells) explosions have killed 10 over the last 20 years, according to Scientific American, and others have noted that solar manufacturers pollute streams and natural waterways in China. Solar installers have also been killed or injured falling off roofs. Approximately 46 people in all have been killed as the result of the wind industry over the last few decades. Twenty-three died during construction. Only four members of the public, including one woman who parachuted into a turbine, have died.

The key difference here is that it is more difficult to set off cataclysmic chain reactions in the realm of renewables. A simple way to figure this is to ask people where they would prefer to live: near a solar farm, a coal plant, nuclear reactor or a wind farm?

As to costs, and speed of setting up plants too, renewables are ahead. Yes, the cost factor may seem prohibitive but this is simply due to the highly subsidised fossil fuel energy. Cost of oil is on the rise and so will be the case as coal begins to peak. Which will be before the middle of this century. Not to say that we shut down all our coal power plants, but start thinking of going slow on them and picking up on the renewables.

So, what are we waiting for?

Water Day

On World Water day, let us remember that almost 1 billion people lack access to safe water supplies, and 2.6 billion are without access to basic sanitation.

Approximately 10% of the global burden of disease worldwide could be prevented with improvements to water, sanitation and hygiene and better water resource management.

Wastewater often reaches the environment untreated or insufficiently treated, resulting in major impacts on surface waters and associated ecosystems as well as economic activity that uses these resources.

Meanwhile, the water used to produce food thrown away by households in the UK amounts to about 6.2bn cubic metres a year. That represents 6% of the UK's total water footprint, which includes water used in industry and agriculture. About a quarter of the water used to grow and process the wasted food originates in the UK, but much of it comes from countries that are already experiencing water stress.

An expanding city like Bangalore has to take stock of its water supplies before planning any further. It still has about 386 lakes left, even if the status of 121 lakes is unknown. Up to 100 lakes have disappeared as they have been converted to various urban uses including bus stations, roads, layouts, garbage dumps, truck stands, etc. The remaining lakes have become useful drainage for effluents.

The effluent issue has been a serious one with discharge nearly tripling from 2007 to 2010. Much of this increase has come from the mushrooming of small industrial units which cannot afford a treatment plant. Given the sporadic inspection by pollution board, effluents are easily transported and dumped into water bodies.

Till 1974, Bangalore did not have water from Cauvery, and relied purely on the tanks and lakes. However the population was then 2.3 million. It is now over 6 million and by 2015 will touch 10 million. Even the last phase of Cauvery water supply scheme will not be able to take on these numbers for too long. Managing its water bodies better is the only sustainable way out.

But a problem becomes a problem only when it is visible. Right now, a large section manages to find the precious water it needs. When the problem looms large, hopefully there still will be time.

Fact or fiction - cheap solar energy?

Now that the N word has put a scare among public and governments, maybe it is time to work hard on the renewables. And thinking of renewables in summer, one looks up to the sun!

The sun strikes every square meter of our planet with more than 1,360 watts of power. Half of that energy is absorbed by the atmosphere or reflected back into space. 700 watts of power, on average, reaches Earth’s surface. Summed across the half of the Earth that the sun is shining on, that is 89 petawatts of power. By comparison, all of human civilization uses around 15 terrawatts of power, or one six-thousandth as much.

In 14 and a half seconds, the sun provides as much energy to Earth as humanity uses in a day. In 112 hours – less than five days – it provides 36 zettajoules of energy –as much energy as is contained in all proven reserves of oil, coal, and natural gas on this planet.

Isn't that reason enough to harness that energy? Yet solar power is still a miniscule fraction of all power generation capacity on the planet. There is at most 30 gigawatts of solar generating capacity deployed today, or about 0.2 percent of all energy production. Well, there is the cost. But...

Increasingly, there is a thought among experts that we could be witnessing a Moore's Law in the solar energy field. We would eventually have the solar equivalent of an iPhone – incredibly cheap, mass distributed energy technology that was many times more effective than the giant and centralized technologies it was born from.

The National Renewable Energy Laboratory of the U.S. Department of Energy has watched solar photovoltaic price per Watt of solar modules (not counting installation) drop from $22 dollars in 1980 down to under $3 today. If the 7 percent decline in costs continues (and 2010 and 2011 both look likely to beat that number), then in 20 years the cost per watt of PV cells will be just over 50 cents.

Conclusion: Solar capacity is being built out at an exponential pace already. The exponential trend in solar watts per dollar has been going on for at least 31 years now. If it continues for another 8-10, which looks extremely likely, we’ll have a power source which is as cheap as coal for electricity, with virtually no carbon emissions.

Any arguments?

Offshore wind: economies of scale the answer

The cost of harvesting offshore wind energy may be a lot lower than the early numbers from controversial projects suggest. A leading U.S. researcher explains how and why deep ocean offshore wind can be the cost-effective renewable energy answer.

The cost of electricity from most emerging offshore projects is, he says, very expensive because they have “large uncertainties and a large learning curve. Those costs do not truly reflect where this industry will be in ten years if we scale up the industry properly.”

The team wants to build floating turbines that can be towed out to sea and anchored, eliminating the costs and risks of construction. By doing as much as possible on land, pre-assemble these units, and doing very little in the water, they plan to save money.

Half of the price is transmission and distribution, the other half is generating electrons. The crucial assumption, is that the industry matures enough by 2020 to the point where it achieves the capacity to build 1,000-megawatt projects. At that size, economies of scale will make it possible to build floating wind farms at costs that will meet the low cost goal.

Wind on a surge

The global wind market will start to grow again this year, according to the Global Wind Energy Council (GWEC), installing 40 GW of new capacity.

The Council’s five-year industry forecast published earlier this week predicts that by 2015, global wind capacity will have more than doubled from 194.4 GW at the end of 2010 to 450 GW.

The forecast assumes an average growth rate of 18.2% a year, which the GWEC says is ‘conservative’ compared with growth over the last decade. Even 2010 did see strong investment in wind power, up 31% on 2009 to reach $96 billion, driven primarily by China.

China alone accounted got almost half of the new capacity added in 2010 and could exceed annual additions of 20 GW by 2015. The government’s new five-year plan has set a target of 70 GW, which the country could, in fact, surpass.

Not all winds flow foul!

Coal plants and radiation? Really?

China to reconsider nuclear power plans. Is that good or bad news? In the light of Japan disaster, it seems good. But some people think not. Like George Monbiot at The Guardian. And why?

'Even when nuclear power plants go horribly wrong, they do less damage to the planet and its people than coal-burning stations operating normally. Coal, the most carbon-dense of fossil fuels, is the primary driver of manmade climate change. If its combustion is not curtailed, it could kill millions of times more people than nuclear power plants have done so far. Yes, I really do mean millions.'

He goes on to say that deaths from Chernobyl and Fukushima cannot be ignored but remain 'a tiny fraction of the deaths for which climate change – through its damage to the food supply, its contribution to the spread of infectious diseases and its degradation of the quality of life for many of the world’s poorest people – is likely to be responsible.'

Coal also causes plenty of other environmental damage, far worse than the side-effects of nuclear power production: from mountaintop removal to acid rain and heavy metal pollution. An article in Scientific American points out that the fly ash produced by a coal-burning power plant “carries into the surrounding environment 100 times more radiation than a nuclear power plant producing the same amount of energy.” But we are not panicking about our coal plants, as we are right now with the winds blowing south or eastwards from japan!

Nuke the only option?

After the Japan disaster, the question has come back to haunt us - whether the planned addition of more than 60,000 MW of nuclear power by 2031-32 (as per
Integrated Energy Policy) is in the interest of our society? What are risks associated with nuclear parks like Jaitapur, and other ones in West Bengal, Gujarat, in a nation as populated as India? This is besides the huge cost involved in nuclear power production. Not to forget the problem of waste - Tarapur has 40 years of nuclear waste accumulated and not knowing what to do with it!

Proponents say the explosion at Japan's reactors is not relevant to India where we have safer concrete domes. Well, Kaiga dome did collapse! Also, they say that In India nuclear plants are not placed close to inhabitation.?? If it is about self-sufficiency and 'clean' (can nuclear waste ever be clean?), then nuclear is the best choice, some say.

India's nuclear programme is of 3 stages. At present we are using natural uranium. From it we get plutonium which will be used in 2nd stage reactor. From outcome of 2nd stage reactor we will be getting thorium which will be used in third generation reactor. India has a vast source of thorium which is expected to last for minimum of 460 year. The plan and design is ready for third generation reactor.And then, the nation will be self sufficient. That is the claim.

Is nuclear the only clean option? Or does the solution lie in deploying small, distributed energy sources using those available locally? Or is it in aggressively adopting renewables?

Save 'blue carbon'

Dubbed "blue carbon" because of their littoral environment, mangroves, salt marshes and sea grasses previously undervalued, these coastal carbon sinks are beginning to gain attention from the climate and conservation communities. They can sequester vast amounts of carbon—up to five times that stored in tropical forests.

Because they hold so much carbon, destroying them can release substantial amounts of CO2. People around the world wreck coastal habitats through aquaculture, agriculture, timber extraction and real estate development. To date, human encroachment has destroyed more than 35 percent of mangroves, 30 percent of sea grass meadows and 20 percent of salt marshes.

Stopping such destruction could therefore become an important element in confronting climate change. At the global scale, coastal wetland destruction could account for 1 to 3 percent of industrial emissions; a number that will increase along with coastal wetland destruction.

According to scientists, the main hope for conserving these coastal habitats lies in a combination of economics and science. The first step is recognizing the importance of coastal carbon pools as a significant tool for climate mitigation.

Even without carbon markets nations have obligations to manage their greenhouse gas emissions, which means that the carbon in these coastal habitats can be tallied in national accounts as a way of contributing to their management of global greenhouse emissions. Companies, say the experts, could also start volunteering to launch socially and environmentally friendly coastal habitat projects in the name of climate protection.

Mass extinction predicted

Scientists from the University of California, Berkeley warn that we are on the brink of pushing the planet into its sixth mass extinction if something isn’t done soon. With the steep decline in populations of many animal species, from frogs and fish to tigers, some scientists have warned that Earth is on the brink of a mass extinction like those that occurred only five times before during the past 540 million years.

However, it isn’t too late to save these critically endangered mammals and other species, and bring us up short of a tipping point which would lead to the planet’s sixth mass extinction. It is very important to devote resources and legislation toward species conservation if we don’t want to be the species whose activity caused a mass extinction, note the team.

After looking at the list of threatened species maintained by the International Union for Conservation of Nature (IUCN), the team concluded that if all mammals now listed as “critically endangered,” “endangered” and “threatened” go extinct, whether that takes several hundred years or 1,000 years, Earth will be in a true mass extinction. The findings highlight how essential it is to save critically endangered, endangered and vulnerable species, to ensure the Earth’s biodiversity remains in pretty good shape.

More carbon, less water

Doubling today's carbon dioxide levels will dramatically reduce the amount of water released by plants and hence the rainfall. A doubling of today's carbon dioxide levels -- from 390 parts per million to 800 ppm -- will halve the amount of water lost to the air, leading to altering the hydrological cycle and climate.

As carbon dioxide levels have risen during the last 150 years, the density of pores that allow plants to breathe has dwindled by 34 percent, restricting the amount of water vapor the plants release to the atmosphere, report scientists from Indiana University Bloomington and Utrecht University in the Netherlands in an upcoming issue of the Proceedings of the National Academy of Sciences.

Most plants use a pore-like structure called stomata (singular: stoma) on the undersides of leaves to absorb carbon dioxide from the air. The carbon dioxide is used to build sugars, which can be used by the plant as energy or for incorporation into the plants' fibrous cell walls. Stomata also allow plants to "transpire" water, or release water to the atmosphere. Transpiration helps drive the absorption of water at the roots, and also cools the plants in the same way sweating cools mammals.

If there are fewer stomata, or the stomata are closed more of the day, gas exchange will be limited -- transpiration included.

If transpiration decreases, there may be more moisture in the ground at first, but if there's less rainfall that may mean there's less moisture in ground eventually. This is part of the hyrdrogeologic cycle. Land plants are a crucially important part of it. While it is well known that long-lived plants can adjust their number of stomata each season depending on growing conditions, little is known about the long-term structural changes in stomata number or size over periods of decades or centuries.

Yet another vicious circle!

Damn the dams?

Floodwaters from the Xiol

Are dams good, or is coal better or is nuclear the best option? You are sure to hear proponents of each espousing the respective energy option. What is the truth? Does it as always lie somewhere in between?

To reduce its carbon intensity by 40 percent by 2020, China has undertaken a five year plan with grandiose plans, among which are big dams. As part of its low-carbon diet, the Chinese government plans to approve new hydropower plants with a capacity of 140 gigawatts over the next five years. For comparison, Brazil, the United States and Canada have each built between 75 and 85 gigawatts of hydropower capacity in their entire history. Achieving the new plan's target would require building cascades of dams on several rivers in China's south-west and on the Tibetan plateau.

Experts believe this would spell disaster for its rivers and biodiversity hotspots. Because of dam building and other factors, freshwater species have on average lost half their populations between 1970 and 2000, and more than a third of all freshwater fishes are at risk of extinction.

International pressure to limit greenhouse gas emissions is the single most important factor behind the huge push for hydropower in China. But, in the process is it set to create new crises? Should emissions reductions come at the cost of biodiversity and loss of rivers?

Natural gas: the next choice to coal?

Well, if solar and wind come with their set of problems, is natural gas a better option? Should we opt for more pipes rather than wires overhead?

Natural gas advocates argue that it generates 50 percent fewer greenhouse gases than coal when burned. And since natural gas is more widely available than ever, thanks to newer more efficient—though in some cases environmentally damaging—extraction techniques, some think it should be playing a larger role in a transition away from coal.

But although natural gas generates less greenhouse gas than coal when burned, when its total life-cycle emissions associated with extraction and distribution are factored in, it does not seem much cleaner than coal. A 2007 lifecycle analysis of natural gas production, distribution and consumption found that when one factors in the total emissions associated with not only the end use of natural gas but also its extraction and distribution—much of it can leak when it is pulled out of the ground and then piped to power plants and other customers—it doesn’t seem so much cleaner than coal after all. The U.S. Environmental Protection Agency (EPA) says that loose pipe fittings and intentional venting for safety purposes on natural gas lines cause annual greenhouse gas emissions rivaling that produced by 35 million cars each year.

The World Bank estimates that emissions from natural gas extraction operations alone account for over a fifth of the atmosphere’s total load of climate-changing methane.

“When scientists evaluate the greenhouse gas emissions of energy sources over their full lifecycle and incorporate the methane emitted during production, the advantage of natural gas holds true only when it is burned in more modern and efficient plants,” reports Abrahm Lustgarten on the investigative news website, ProPublica. “But roughly half of the 1,600 gas-fired power plants in the United States operate at the lowest end of the efficiency spectrum.”

Definitely, solar and wind seem more benign!

Now, who will stop the wind?

The spectacular growth in recent years in the number and size of renewable energy sources across the European Union -- particularly wind and solar power -- driven by high subsidies and government rhetoric on climate change has left the national electricity grids scrambling to cope. Estimated costs of strengthening, upgrading and smartening the grids are put at up to €100 billion ($138 billion) over the next decade alone. And that only takes into account onshore networks.

A study earlier this year by German company Energynautics commissioned by Greenpeace found that grid upgrades totaling up to 140 GW of capacity would be necessary across the European Union and eastern and northern Europe to cope with the vast increase planned in renewable energy.

Germany produces only about 5 gigawatts of actual wind power, and when recently that output shot up to a record of more than 20 GW on a particularly windy weekend, cross-border connections to grids in neighboring countries had to be shut down because they couldn't handle the surging power. The Germans need to build 17,000 kilometers of new grid just internally.

With the United Kingdom, for one, aiming to get some 30 GW of electricity from wind farms in the North Sea within the next decade as part of its E.U. target to get 15 percent of its power from renewables by 2020, there are also proposals to build a giant subsea grid to bring that power ashore.

Problems are not just of power loss and heat generation over long distances, but also of public acceptability and cost. As with onshore wind farms, there is frequent public outcry over the placement of power pylons while placing it underground has technical issues like cooling.

Countries are still struggling to build their own networks, let alone when it comes to crossing borders and the only country really doing it is China, using European technology!

So do we see a problem of plenty, or that of being unprepared? And do we learn a lesson from the early beginners?!