Letters - October 15 2008
I recently came across your 1-15 August 2008 issue on ‘After oil’. Can you please tell me the potential of various renewable energy sources? Also, kindly tell me what other fuel option do we have apart from petrol and diesel.
Here is a chart of the potential of some renewable energy sources according to the Ministry of Nonconventional Energy Sources (MNES):
|Solar thermal||35 MW/sq km||–|
|Solar photovoltaic||22 MW/sq km||2.24 MW|
|Biomass||3500 MW||381 MW|
|Small Hydro||15000 MW||1663 MW|
The chart also shows how much of the energy sources’ capacity has been used. Now, as for fuels other than petrol or diesel, here are two options:
Hydrogen can be derived from both renewable and non-renewable energy sources, and there are two methods of producing hydrogen:
• It can be manufactured at roughly 77 per cent thermal efficiency by the method of steam reforming of natural gas. Here, it is a derivative fuel like gasoline.
• It can be produced by electrolysis of water (splitting water molecules using electricity). Here, it is a form of chemical energy. Hydrogen, when produced through electrolysis, acts as a carrier like a battery.
There are two methods of using hydrogen: combustion and fuel cell conversion. In combustion, the hydrogen is “burned” in internal combustion engines in the same way as in traditional gasoline (petrol). On the other hand, a fuel cell converts the chemicals hydrogen and oxygen into water, and in the process, produces electricity. Hydrogen has often been called the ‘perfect fuel’, mainly because its use in fuel cells produces no harmful emission. But the production costs are too high to replace petrol cars in the near future.
One alternative that everyone is talking about is, ofcourse, biofuel. Biofuels are petrol additives, such as ethanol and biodiesel, manufactured from plants, crops and animal feedstock. Their demand is the highest in the US and European countries. They have various advantages like:
• Less toxic-releasing none of the poisonous gases emitted by fossil fuels. So they ensure better air quality.
• Drastically cut down wastes, as the left over plant masses can be recycled as fodder or as fertilisers.
• They are made of renewable, locally available resources. So they make nations less dependant on others for supply of fuels.
• Some of these oil-yielding plants grow on poor soils and need very little water or manure to survive.
• The production process creates fresh employment in the villages and rural areas.
Dear Pandit ji,
I was planning to write a mail to you for a long time. I’ve finally been able to now. I must say that your magazine is one of its kinds. The issues are extremely interesting, informative and enlightening. The way you deal with the topics is praise-worthy. I have one suggestion. Can you please do a story on animals? Environment is also about them, right? It can be anything related to animals… may be just facts and figures about them… Kindly take note of this.
Keep up the good work!
Here are two of the varieties of biofuels being tried out in the country: Jatropha and Pongamia: The seeds of plants Jatropha (Jatropha curcas to scientists; ratanjyot in Hindi) and Pongamia (Pongamia pinnata; karanj in Hindi) yield oil that, after processing, makes biodiesel.
The jatropha blend reduces greenhouse gas emission by half. Scientists claim that as the conversion process improves with time, emission level will be zero! Jatropha is ideally suited to India because it is a hardy plant that can to grow in abundance in dry, arid zones.
Ethanol: It is made by fermenting molasses or gurh (a product of sugarcane). Ethanol, CH3CH2OH, is an alcohol – a group of chemical compounds whose molecules contain a hydroxyl group, OH, bonded to a carbon atom.
Starches from potatoes, corn, wheat, and other plants can also be used in the production of ethanol by fermentation. However, the starches must first be broken down into simple sugars.
Ethanol is easily blended up to at least 10 per cent with modern conventional petrol vehicles, and much higher levels in vehicles that have been modified to accommodate it.
The Indian government launched a programme to promote ethanolblended petrol in 2003. However, India’s situation is
quite different from other countries.
This is because even its ‘wastelands’, which are deemed as the “perfect” option for growing biofuel crops, sustain a large population. So, it must also ensure that the people who literally live off these seemingly useless tracts are not affected. Biofuel is a tempting option. But, it is predicted that biofuel targets could create 600 million additional hungry people in the world by 2025. So, the choice is not that simple.
Dear Pandit ji,
The latest Gobar Times about rocks is great! I just loved it! I have one question that you did not talk about in the story: what are rock formations?
Dear Saira Khan ji,
Rock formations are surface rock outcrops (or simply rocks) that are noted for their shapes. They may be isolated, scenic or spectacular formations. They are usually the result of weathering and erosion by forces like wind and water.
Geologists use various terms to describe different rock structures: Inselberg, Peak, Stack, Mesa, Butte, Escarpment, Gorge, Sea cliff, River cliff, Stone run, and so on.
In India, Jabalpur Marble Rocks of Madhya Pradesh, and Face Rock of Hyderabad are the most well-known natural formations.