Sun worshippers

A Spanish solar thermal plant, PS20, has brought fresh proof of the efficacy of solar thermal power.

Abengoa Solar operates the new plant, which has a power capacity of 20 megawatts, enough juice to power about 10,000 homes. The plant uses 1,255 heliostats (motorized mirrors) to reflect sunshine onto a fixed focal point. The heliostats follow the sun’s path throughout the day to catch maximum rays.

With a surface area of 1,291 square feet each, the massive mirrors working together focus over a million and a half effective square feet of sunlight on the apex of the tower. That heat energy can be used to boil steam to turn turbines, or stored for later use.

Concentrating solar power (CSP) has also provided the answer for solar storage. Electrical batteries while affording an option for small units are expensive, and impractical for utility-scale power storage. In CSP, as it is the heat that is being used instead of light, the heated water or fluid can be stored in insulated tanks and used when required.

Current technology can store solar-generated heat for up to 7-12 hours.

Solar thermal not only can provide for stand-alone generation but can work with fossil-based plants by providing the heat and reduce the need for coal and help reduce emissions.

The potential for places in the tropics where the sun burns down powerfully cannot be over-emphasised. The land required, of course, is on a slightly large scale but technology is developing that is already showing optimum designing of the mirrors to cut space requirement by half.

If you have any experiential insights on this technology, let us know.

Money to go clean

Developed countries should pay at least 0.5 percent of their economic output to help less wealthy nations build wind turbines, solar plants and use other clean technologies, China, India and South Africa said. The three countries proposed this to the United Nations, which is leading negotiations for a new climate- protection treaty.

The US stand has been that the developing nations too must accept emission targets. The EU has in principle agreed to fund clean energy in the third world but not specified any amount.

The contention of developing nations is that 0.5 percent of the GDP is what the rich nations are already giving as aid to poor nations and it hardly constitutes a pinch. The demand for a specific fund may not be as tough to wrest out as a bigger demand on emission reductions.

Industrialized nations should reduce their greenhouse gas emissions 40% by 2020—which is more than twice most countries' targeted reductions. This will make room for the aspiring countries to "modernize their economies."

India and China have indicated willingness to consider differentiated reduction targets. But expecting the rich world to agree to double the reductions could be tantamount to asking for the moon!

As is well known, Kyoto Protocol notwithstanding, emissions have not shown any reductions but have been continuing the climb.Protocols can be made and re-made. What difference will it make unless these have teeth? Who will monitor for the planet?

Lasting homes

Homes in the future could last forever. Well, almost! A concrete material developed at the University of Michigan can heal itself when it cracks. No human intervention is necessary—just water and carbon dioxide to heal and form a thin white scar of calcium carbonate.

Self-healing is possible because the material is designed to bend and crack in narrow hairlines rather than break and split in wide gaps, as traditional concrete behaves.

Failures often occur when traditional concrete is strained in an earthquake or by routine overuse as it is brittle and rigid. But the flexibility of engineered cement composite, or ECC (which acts more like metal than glass), prevents this occurrence. The bendable ECC remains intact and safe up to tensile strains of 5 percent where traditional concrete fractures and can’t carry a load at .01 percent tensile strain.

At present, building structures are constructed using steel bars to keep cracks as small as possible. But they’re not small enough to heal, so water and salts can penetrate to the steel, causing corrosion that further weakens the structure. Self-healing concrete needs no steel reinforcement to keep crack width tight, so it eliminates corrosion. And costs! And energy!

Natural materials have long been shown to be the best when it comes to temperature modulation and costs. Bamboo, kemp, etc have been used effectively. But more and more traditional homes all over the country are being replaced by concrete structures – for its strength. Are we headed in the right direction?

Rivers drying up

Some of the world’s biggest and vital rivers are drying up due to climate change, according to US National Center for Atmospheric Research. That water is drying up has been known, but the study pins this down on climate change.

The study assessed 925 rivers using both satellite data and on the ground measurement, and found that while the flow in some rivers had increased as a result of changing rainfall patterns and glacial melt water, a significantly larger number had lost water.

Overall, the study found that from 1948 to 2004, annual freshwater discharge into the Pacific Ocean fell by about six per cent, while the annual flow into the Indian Ocean dropped by about three per cent.

Among the rivers are the Ganges, the Niger and the Colorado.

Fast melting rates of glaciers have warned about impending water scarcity in the Gangetic basin. Is there any plan in place to address the drinking water, irrigation needs which are going to be dire?

The map shows areas of the globe where the situation is bad. Red indicates the regions that have witnessed a drop in the run-off. Blue at the other end indicates rise in water.

The groundwater situation is no better. India has over 22 million wells and a city like Bangalore has an estimated 200,000 borewells. Half of them no more yield water!

Recharging these deep wells with rainwater is among the damage repair measures suggested.
But more important is the need for a judicial management of these resources. Mapping aquifers, maintaining a log on the water availability across time, hiring hdro-geologists in water boards, putting in place a law that makes recharge mandatory while dropping borewells, etc could help.

Even as questions of ownership are hazy when it comes to groundwater, it is vital that people realize the value of water and not overuse or waste it.

Are you recharging the ground below your home?

China takes a lead

It is not yet official but according to a high-ranking official, the Chinese government is planning to impose a carbon tax to tackle emissions of carbon dioxide, sulphur oxide and wastewater. Aimed at slowing global warming, it is directed at coal and petrochemical products.

An environment tax and an energy tax are also on the anvil. The energy tax would mainly target the coal industry because the petroleum industry already pays consumption tax. When the energy tax is put into practice, companies will pay at least 40 yuan ($5.85) per tonne of carbon dioxide emitted.

Not so bad after all, for the biggest polluter in the world today! Seventy percent of China's energy comes from coal, the largest contributor to carbon emissions. China plans to build 500 coal-fired power plants in the next decade, at the rate of almost one a week

Going by its announcements, China is doing a good job of the tight-rope walk between development plans and growing emissions. A February analysis by HSBC Global Research in Hong Kong projects that nearly 40 percent of China’s proposed $586 billion stimulus plan is going toward public investment in renewable energy, low-carbon vehicles, high-speed rail, an advanced electric grid, efficiency improvements, and other water-treatment and pollution controls.

This makes China, according to a recent analysis, “the largest alternative energy producer in the world in terms of installed generating capacity.”

This massive stimulus plan will spend over 3 percent of China’s 2008 gross domestic product annually in 2009 and 2010 on green investments. China has adjusted its stimulus spending slightly since the HSBC analysis and trimmed spending on water treatment and environmental cleanup, but maintained huge investments in upgrading its power infrastructure, and more than doubled investment in technical upgrading and research and development.

Clear indications of how serious China is in ‘using this economic crisis to position itself to be the world leader in efficiency, green transportation, and clean and renewable energy’. China is a leading manufacturer of photovoltaic (solar) cells, second only to Japan, and is set to be the world’s leading manufacturer of wind turbines by the end of 2009.

Lessons there for all aspiring powers?

Shed a pound for the planet

Obesity is bad for you, and for the planet. The more mass you have, the more you need to eat to keep it going, and the more you tend to rely on transport. The connection is quite obvious but if you need proof, a recent study has concluded the same. Conducted in the UK, it found that more obese people meant more greenhouse gas emissions a year, almost 60 mega tones!

Greenhouse gas emissions from food production and car travel in the fatter population would be between 0.4 to 1 giga-tonnes higher per 1bn people, they estimated.

As noted, this is a global issue, not restricted to the UK. The fat population is growing everywhere. As the study notes, it would be good for all stakeholders, earth included, if we shifted to our 1970s eating habits. More veggies, less meat.

On Earth Day, some more alarming news: the National Oceanic and Atmospheric Administration says that the concentrations of carbon dioxide and methane, the two most important greenhouse gases released through human activities, rose in 2008.

Collected from 60 monitoring stations from around the world, it shows that the concentration of carbon dioxide has reached 386 parts per million in the air. The pre-industrial peak in concentrations was 280 parts per million and the ideal level to avert disaster is 350 ppm. But given the trend, chances are it will exceed 450 parts per million this century.

Methane levels rose in 2008 for the second consecutive year after a 10-year plateau. Methane persists only a few years in the air, but is about 25 times more efficient than carbon dioxide at trapping heat.

What can we do? Not to keep pressing the panic button, but just to start some action. Is there one activity you can choose to adopt from today that will ease the carbon load on the planet? It could be as simple as losing weight! Write in to us, share your thoughts, so others may be inspired and follow.

Earth Day Facts

Did you know how we are scarring the face of earth?

Just in a year,

3million tons of iron ore, 575 thousand tons of tin, 330,000 tons of bauxite (for aluminum), and 34,000 tons of copper will be ripped from the Earth.

Burning the oil and other fossil fuels will release 70 million tons of carbon dioxide into the atmosphere.

200 million tons of topsoil will be lost through erosion from croplands.

50,000 acres of forest will be eliminated.

Between 20 and 500 species will disappear from the planet forever.

Be the planet’s saviour. Consume less, waste lesser and plant more trees.

Recycled glass uses only 2/3 the energy needed to manufacture glass from scratch. For every soft drink bottle you recycle, you save enough energy to run a television set for an hour and a half.

A full bath tub requires about 70 gallons of water, while taking a five-minute shower uses 10 to 25 gallons.

Leaky faucets that drip at the rate of one drip per second can waste more than 3,000 gallons of water each year.

Pay Attention to Your Fridge. In an apartment building, 25% of your electric bill may go towards the fridge. Keep its compressor coils clean to ensure your energy bill stays low. Cover Your Food. Check the fridge's seal. Fill your fridge with water jugs to keep it full and colder.

If you have a window-mounted air conditioner, you can save energy and money by shading it from the sun. The cooler the air conditioner, the more efficient it runs.

On average a tree will absorb 730 kg of carbon over it's lifetime and releases enough oxygen back into the atmosphere to support 2 human beings.

EARTH DAY. April 22. DO YOUR BIT.