Wood has been the most common source of energy since the advent “human beings on the earth. Population being thin everywhere it seemed to be everlasting source.
Increase in population meant occupation of land for residential houses. That is how forests started depleting and disappearing ‘too. It was not simply a loss in the potential source of energy but created environmental problem too.
Since 18th century coal started replacing wood id was known as black gold. But the scientists knew that as the industries grew and the population increased coal reserves may last only for a hundred or two hundred years. The discovery of petrol of course proved a boon. But; the late Shah of Iran put it the stocks may last only by the first quarter of the 21st century.
Nuclear or atomic energy started replacing these conventional sources of energy after the Second World War. Number of plants increased in the developed countries to an extent that by the eighties of the 20th century this so was considered a conventional source of energy. It is based on the principle of fusion of a heavy atom of uranium or allied metals like plutonium lat releases unlimited energy. It has two limitations. The stocks of uranium are limited.
Moreover the fission produces dangerously radioactive waste. Dumping of the waste is a problem. Radioactive would have an adverse effect on the living being and plants. The large number of leakage in the nuclear plants took many lives, environmental hazards apart.
Naturally search for a clean source of energy continued. Countries like Mexico and Philippines secured energy from volcanoes—a very hazardous Endeavour of course. The initiation of biogas by India was followed by China. China is much ahead of India in this respect as it has no inhibition.
Experiments of securing power generation through wind mills have been successful in a umber of countries. India too has a big wind mill power generating centre at Tirunelveli in Tamil Nadu. Sea waves too have been exploited. But one of the important sources is the sun itself. Sun lamps are available in India and BHEL has manufactured solar energy generators. It is expected that if attention is paid to this perennial source the problem of power generation will be solved for ever.
One of the constituents of the solar plant is mica that is available in abundance. Israel and Japan have exploited this source to such an extent that a large number of residential areas do not take power from the national or state grid.
Another big source of energy, specially in metropolitan cities is the garbage and the refuse. Big tanks at Okhla in New Delhi receive human excreta through drains from a particular area. It is recycled in a way to produce gas that is supplied to the nearby area for cooking. It can also be used for lighting the household. The left overs after processing provide rich natural fertilizer. The city garbage, in Mumbai, is supplied to a firm that processes it in a way ultimately changing the garbage into small coal ingots that are used in place of coal in all manufacturing concerns. There are a number of such plants in Mumbai. All these unconventional sources of energy are free from environmental hazards and are economical too.
The search for still better sources of energy has been continuing. Princeton University in New Jersey in the USA has the credit of making a break through in the generation of energy by fusion. Near about 500 scientists have worked on the principle—some of them for 20 years. Ultimately “The experimental hydrogen reactor at the Princeton Plasma physics laboratory unleashed the burst of energy on Friday, December 10, 1993”. Unlike fission that is used in the present nuclear reactors and atomic bombs fusion is used in the Princeton test and in Hydrogen bombs.
In the final test in 1993 two types of hydrogen nucleus were used—Deuterium i.e. one proton and one neutron and tritium i.e. with an additional neutron. The hydrogen is brought to a temperature of hundreds of millions of degrees.
The atoms begin to combine or fuse. “The particles combine into an alpha panicle and a spare neutron in a commercial reactor. The neutrons would hit metal and heat it up. The heat would be used to turn the turbines of electric generators.” The four second burst of December 10, 1993 produced a fusion power equivalent to about 3 million watts. It was nearly double the 1.7 million watts produced in 1991 by the joint European Torus which is the chief rival of the Princeton machine and originated near Oxford in England.
In the next nine months the Princeton group expected to increase the power of its reactor to ten million watts enough to power about 3000 US homes. Although it has achieved six times the level achieved by Torus and does not produce any radioactive waste products the machine consumed about eight times as much energy as it produced. This ratio, of course, is a vast improvement over previous experiments. The scientists hope that they will be able to have a cost effective fusion in the years to come. Then it will, most probably, be the perennial source of energy in the world.