SCIENCE TRIBUNE Thursday, May 25, 2000, Chandigarh, India

Solar power plants offer hope
by K.C. Singhal

EVEN in April the ambient temperature was 46°C at some places in the country and the states of Rajasthan, Gujarat, Andhra Pradesh and Orissa were in the grip of a severe drought and famine-like conditions — the shortage of water, food and fodder. The situation was helpless, painful and grim. At some places the water level had fallen considerably. In June the ambient temperature might touch 50°C or even more and then one can visualise the plight of the people and livestock in those areas.

Supercomputers out of PCs
INKING several personal computers (PCs) to form supercomputers is offering a faster and cheaper alternative to long waits at national supercomputer centres, say scientists.

Science Quiz
by J. P. Garg

New products & discoveries — IT Digest



Solar power plants offer hope
by K.C. Singhal

EVEN in April the ambient temperature was 46°C at some places in the country and the states of Rajasthan, Gujarat, Andhra Pradesh and Orissa were in the grip of a severe drought and famine-like conditions — the shortage of water, food and fodder. The situation was helpless, painful and grim. At some places the water level had fallen considerably. In June the ambient temperature might touch 50°C or even more and then one can visualise the plight of the people and livestock in those areas.

Obviously to meet such situations affecting crores of people some temporary arrangements have been made like daily supply of drinking water through rails, ships and other means, food specials and fodder specials through trains and trucks. Short-term measures of employment have also been made. In a country like ours drought has now become a recurring phenomenon as we came across similar conditions during 1985-87. No permanent solution has so far come in tackling this menace.

In 1992 there was a programme to spend Rs. 800 crore by the Government of India for pumping water in drought prone areas of the country by installing pumps through solar power plants based on photovoltaic system. The idea was to have some 200 power plants for pumping water in far flung areas of the country, costing Rs. 4 crore per unit. Obviously, these were meant for pumping water from deep wells. I have not come across any such unit for pumping water from deep wells. However, I have learnt that one power plant of 100 KW capacity has come up in Aligarh (UP) producing grid quality electricity. One more power plant is also there in UP.

The Tribune of April 25, 2000 carried a news item that 500 solar tubewells for rural areas would be provided to the farmers in Punjab. Each connection costs Rs. 35000 to the farmer against the total cost of Rs. 4.65 lakhs per tubewell connection. The Punjab Govt. would provide Rs. 60,000 per connection to PEDA (Punjab Energy Development Agency) and the rest of the amount would be contributed by the Central Govt. The solar system fitted with the tubewell would produce 1800w of electricity and the tubewell would run on a 2 H.P. motor. Obviously the system is for shallow well irrigation. Using it in deep well is impossible. Even if it works for shallow wells, so far so good. Otherwise because of certain operational difficulties the unit may not come up to the desired expectations. So with fall of water level in Punjab by 5 to 7’, the utility of such units is doubtful. Above all how costly the system is. If a private party is there to supply the system, it will become bankrupt in no time and if subsidy (huge subsidy) by State and Central Governments is withdrawn, who will install such units?

The present day photovoltaic system in the country is not very efficient. The cost is also very high. Unless the electrical conversion from solar energy is made efficient and the cost is reduced, photovoltaic system (present day) would not serve the purpose of pumping water.

Because of intense heat in summer, site insolation is also highest and we must make use of this energy to really mitigate the sufferings of our people, mostly those living in far-flung areas where we have no electricity and water. We must have water for drinking-our primary goal in such circumstances. In normal times this solar energy, which is so freely available and costs nothing, must irrigate our lands or must provide electricity to our homes there. If photovoltaic system presently available cannot help us we must switch over to other methods of utilising solar energy which prove to be cost effective, reliable and do not require any subsidy. Subsidies are a big burden and drain on the economy of the nation.

Solar power plants based on the concept of parabolic through line focus concentrating collectors would do the job efficiently and economically. Solar energy is a low grade thermal energy, intermittent in nature, its intensity varying since morning till evening and no energy during night what is needed for efficient use of solar energy are three things, (1) Concentration of solar insolation (2) tracking of solar collectors with the movement of the sun and (3) reduced losses. All the three can be incorporated in this system.

A 150KW solar powered facility is given in the diagram below. Solar energy is collected by a field of about 4500 m2 with parabolic trough line focus concentrating collectors 2140m2 (23040 sq. ft.). A 113500 litre or 30,000 gallon thermal storage tank is used to buffer the insolation transients and extend system operations into night time and cloudy periods. The collected thermal energy is converted to electricity in an organic Rankine heat engine.

Such a system would operate three pumps of about 50 KW each. Water can be pumped from depths up to 300’ or so, as I am sure if there is water at a depth of 150’, there would be other layers of water up to 300’ which could be easily tapped. Each pump can draw water 5300 litres (1400 gallons) per minute from 300’ deep wells.

Each such power producing unit should not cost more than Rs 2 crore. During normal times 200 acres of land can be irrigated. About 70% of the annual electrical requirements for a 100 home community could be served by this system.

The needs of many small communities are best served by dispersed power sources which can be located nearby and controlled by the users. Solar powered systems offer a special advantage. All that is needed is right planning and prompt implementation, which will not only take care of drought but also of rural poverty in future.

Such a system would be far cheaper than the present photovoltaic system. About 1000 such units, if installed in the country would go a long way in mitigating the sufferings of the people. People would not have to go miles and miles in search of drinking water.

The writer is a power and energy consultant.


Supercomputers out of PCs

LINKING several personal computers (PCs) to form supercomputers is offering a faster and cheaper alternative to long waits at national supercomputer centres, say scientists.

A Pennsylvania state engineering professor says low-cost personal computers linked to form systems with supercomputer-like capabilities — popularly known as Beowulf clusters — can be a faster, cheaper alternative for many chemists, physicists, aeronautical engineers, electrical engineers and others who now have to wait to use machines at national supercomputer centres.

According to Dr Lyle Long, professor of aerospace engineering at the Pennsylvania University, “Lots of people who are using supercomputer centres are running only 16 processors at a time”. They may find it more convenient to use these kinds of clusters and to leave the supercomputer to those who need 200 or more processors, a report from the university says.

PC based supercomputers, which picked up in the nineties, are the most cost-effective, says V.P. Bhatkar, founder-director of Pune-based Centre for Development of Advanced Computing (C-DAC) and one of the key brains behind India’s PARAM range of supercomputers.

One of the prime reasons for the advent of PC-based supercomputing is that supercomputers based on specific machines and hardware do not continue for long due to fast changing technologies, he said.

“That is the reason why most Japanese supercomputing architectures have become obsolete”, he told PTI.

Use of a cluster of PCs for supercomputing in just an extension of use of a cluster of workstations (COWs) — which was used by C-DAC for PARAM, Bhatkar said.

“PC’s were not very powerful earlier. Now that they have almost taken over workstations, supercomputers based on them would prove to be the most effective,” he said.

“There are some very important scientific questions in surface chemistry, supercritical fluids, chemical kinetics and aeroacoustics that can be tackled using relatively small-scale molecular dynamics, integral methods, or finite differences codes,” Long says.

“However, one often needs to run highly complex codes repeatedly to either build up statistical data or vary input parameters. One can very easily use the Message Passing Interface (MPI) paradigm, which is free and can be downloaded from the Internet, combined with the Fortran or C programming languages, to run thousands of different cases in a very short amount of time,” Long says.

MPI is the software environment needed to accomplish supercomputing over a network of PCs MPI I & II are the accepted standards worldwide.

At a recent Aerospace Science Meeting and Exhibit, in Reno, Nevada, Long ran the examples on Penn State’s COCOA, the cost effective computing array, a 50-processor cluster of off-the-shelf PCs connected via fast Ethernet. The system, built to study complex fluid dynamics, has 13 gigabytes of RAM memory and 100 gigabytes of disk space. It cost about $ 100,000 in 1998 and would cost about half of that today. A supercomputer of similar power would cost about $ 750,000.

In a paper presented at the meeting, Long and colleague Kenneth Brentner from NASA Langley Research Centre, Hamptor, described a self-scheduling version of the WOPWOP aeroacoustics code, a standard tool used to predict helicopter noise.

“The WOPWOP code is a relatively small, computationally efficient code that can compute the noise signal from a helicopter rotor in tens of seconds (in some cases) on a scientific workstation,” the authors explain.

“Although this sounds like a small amount of time, it is not unusual to compute the noise at thousands of observer locations on a surface to characterize the noise directivity. For example, if the computation for a single observer takes only 30 seconds but there are 1024 observer locations, the total Central Processing Unit (CPU) time required will still be more than 8.5 CPU hours”.

In fact, in the mid-90s, IBM started using PC-based supercomputing with 14 parallel architectures running in its different laboratories across the world, Bhatkar said.

However, strong network technologies, robust software environment and techniques for “virtual share memory” need to be developed for furthering PC-based supercomputing.

Virtual share memory is a concept where software layer gives the illusion of using a single memory despite the use of multiple memories from different PCs.

A network protocol with “low latency” and high bandwidth is required too as Ethernet, the most popular network protocol used worldwide, will not be suitable due to its “high latency”.— PTI


Science Quiz
by J. P. Garg

1. “If a system in a state of equilibrium is disturbed, the system tends to neutralise the disturbance and restore the equilibrium.” Who enunciated this principle in 1888?2. This chemical is banned for use on animals but still animals are injected with it so that they yield more milk. In human beings, this chemical causes hormonal imbalances, weak eyesight, cancer etc. Which chemical are we talking about, that is quite in news these days?

3. Scientists have recently found that the sun has a much younger brother that rotates around the sun in an orbit of radius about 6,000 billion miles. What is the name of this dark star which is thought to be responsible for showering the earth with comets and meteorites?

4. It is diagnosed that the body of a patient has lost the power to fight any infection. Name the disease the patient is suffering from.

5. “For a given temperature and wavelength, the ratio of the emissive power for all bodies is the same and equal to the emissive power of a perfectly black body at that temperature.” What is this law called?

6. It has been found recently that the use of EM in place of chemicals for growing crops can help decrease environmental pollution and can also be a boon for farmers. What does EM stand for?

7. The brightness of a star depends on the rate of energy emitted by it and that of a planet, a satellite or a comet on the solar radiation reflected by it. What is the name of the scale introduced to measure this brightness of different objects as seen from the earth?

8. Roots normally grow underground at the base of a plant. But in some plants roots grow from their stems and branches. These roots provide nourishment to the plant and enable it to cling onto other plants or buildings for support. What are such roots called?

9. “Azinomoto”, normally used in Chinese food due to its taste and flavour, causes headache and a feeling of tightness around the face. It is said to be even carcinogenic. What is this salt chemically?

10. The Russian cosmonaut Valery Polyakov set a record in 1994-95 on board the Mir space station. What was the record?


1. French chemist Henry Louis Le Chatalier 2. Oxytocin 3. Nemesis 4. AIDS 5. Kirchhoff’s law 6. Effective microorganisms (mixed culture of selected species of organisms) 7. Apparent magnitude 8. Adventitious roots 9. Monosodium glutamate 10. Longest space stay of 437 days.


New products & discoveries — IT Digest

Windmills of the future
Going back to the future seems to be the in-thing with some progressive Germans as they think up of novel ways of conserving energy. The latest is the gaining popularity of windmills to harness energy.

Mini windmills which can be installed on the terraces of houses have gone up on sale and the manufacturers are laughing all the way to the bank. You can get these fully functional miniatures in toy shops, in cigarette shops and even in petrol pumps.

In fact, wherever people go to shop the windmills are up for sale. Such is the craze for these $ 90 each windmills that the German manufacturers are getting inquiries from Holland — the home of windmills.

Windchill Info engine
PTC, a leading provider of collaborative product commerce solutions, has announced Windchill Info engine release 4.0 that further broadens its unmatched capabilities in integrating data from varied information systems for web-based collaborations.

Windchill Info engine allows companies to deploy B2B collaboration portals that streamline business processes and accelerate the global introduction of new products.

Windchill Info engine based portals are browser based composite application that intuitively display and allow modification of information in multiple disparate information systems without having to change the underlying information systems.

First global e2e Services company
U.S. Interactive Inc., a leading Internet professional services company has announced that it has entered into a definitive merger agreement to acquire SoftPlus Inc, a privately-held, leading e-solutions company based in Cupertino, CA.

The acquisition of SoftPlus will enable US Interactive to redefine the Internet professional services landscape by offering the global 2000 innovative and end-to-end (e2e) solutions to extend their businesses from behind the web to beyond the web.

The acquisition will result in the creation of a global Internet professional services organisation offering clients a unique depth and breadth of experience.

Citrix internet solution
Citrix Systems said its MetaFrame application server software has been chosen by SAP AG to expand the application access capabilities of my Workplace, an enterprise web portal that gives users personalised, role based access to all the applications and tools they need from a single point. is the internet solution that connects employees, customers, suppliers and business partners as if all were one company.

Citrix MetaFrame can be used to provide access to any Window-based application from workplace.

— R. Suryamurthy and Gaurav Chaudhary