Renewable energy by mathan

RENEWABLE ENERGY

The past century, witnessed the indiscriminate exploitation of conventional energy resources such as fossil fuel, coal etc., which damaged environment, polluted atmosphere and contaminated water, land and air, the essential elements of all living beings.

This has in turn led to many problems being faced today such as ozone depletion and global warming. The alarming exploitation of non renewable sources has caused depletion of precious resources.

Conventional Energy

Hence we have to find out an alternate viable source of energy eliminating the hazard’s of non-renewable energy sources.

Renewable energy is ultimate answer and our energy and research are to be routed in harnessing the renewable energy resources for sustaining the green environment.

Non Conventional Energy

Therefore, alternative sources of energy have become very important and relevant to today’s world. These sources, such as the sun and wind, can never be exhausted and therefore renewable. They cause less emission and are available naturally.

The renewable energy while harnessing reduce chemical, radioactive, and thermal pollution in the environment. They stand out as a viable source of clean and limitless energy. These are also known as non-conventional sources of energy. They are non polluting, clean and conducive to environment and for the sustenance of human beings.

Under the category of renewable energy / non-conventional energy the predominant sources are sun, wind, water, agricultural residues, firewood and bio waste.

A race is going on throughout the world in harnessing the renewable energy resources. Many of the technologically advanced countries have made rapid strides in this area and we have to gear our efforts to harness renewable energy to supplement our ever increasing energy requirements..

Rank Country Total TW-

h/year

Hydro Electricity TW-h/year

Wind Power TW-

h/year

Biomass & Waste

TW-h/year

Solar TW-

h/year

Geo Thermal

TW-h/year

1 China 797.4 687.1 73.2 34 3

2 United States 520.1 325.1 119.7 56.7 1.81 17.0

3 Brazil 459.2 424.3 2.71 32.2 0.0002

4 Canada 399.1 372.6 19.7 6.4 0.43

5 India 162 131 26 4 1

The chart furnished below shows where we are standing in harnessing

the renewable source of energy

From the chart it is evident that though we are having potential of producing 5000 trillion kWh/year under solar energy alone our performance is only 1 TW-h/year which is very dismal.

Solar energy is the most readily available source of energy. It does not belong to anybody and is, therefore, free. It is also the most important of the non-conventional sources of energy because it is non-polluting and, therefore, helps in lessening the greenhouse effect.

Solar Energy

In the next few years it is expected that millions of households in the world will be using solar energy as the trends in USA and Japan show. In India too, the Indian Renewable Energy Development Agency and the Ministry of Non-Conventional Energy Sources are formulating a programme to have solar energy in more than a million households in the next few years. However, the people’s initiative is essential if the programme is to be successful.

Our country is geographically located in such a place where solar energy can be harnessed throughout the year. Thanks to the present efforts and importance extended by the government in boosting the generation of solar and wind energy.

The financial incentives and other infrastructure facilities extended by the government in enhancing the production of renewable energy is indeed a right direction and worthy. Our zone, having abundant solar energy and is most suitable for harnessing solar energy for a number of applications.

Biomass is a renewable energy resource derived from the carbonaceous waste of various human and natural activities. It is derived from numerous sources, including the by-products from the timber industry, agricultural crops, raw material from the forest, major parts of household waste and wood.

Biomass

Biomass does not add carbon dioxide to the atmosphere as it absorbs the same amount of carbon in growing as it releases when consumed as a fuel. Its advantage is that it can be used to generate electricity with the same equipment or power plants that are now burning fossil fuels. Biomass is an important source of energy and the most important fuel worldwide after coal, oil and natural gas.

Traditional use of biomass is more than its use in modern application. In the developed world biomass is again becoming important for applications such as combined heat and power generation. In addition, biomass energy is gaining significance as a source of clean heat for domestic heating and community heating applications. In fact in countries like Finland, USA and Sweden the per capita biomass energy used is higher than it is in India, China or in Asia.

Biomass fuels used in India account for about one third of the total fuel used in the country, being the most important fuel used in over 90% of the rural households and about 15% of the urban households.

Scientists are trying to explore the advantages of biomass energy as an alternative energy source as it is renewable and free from net CO2 (carbon dioxide) emissions, and is abundantly available on earth in the form of agricultural residue, city garbage, cattle dung, firewood, etc. Bio-energy, in the form of biogas, which is derived from biomass, is expected to become one of the key energy resources for global sustainable development.

At present, biogas technology provides an alternative source of energy in rural India for cooking. It is particularly useful for village households that have their own cattle. Through a simple process cattle dung is used to produce a gas, which serves as fuel for cooking. The residual dung is used as manure.

Biogas plants have been set up in many areas and are becoming very popular. Using local resources, namely cattle waste and other organic wastes, energy and manure are derived. A mini biogas digester has recently been designed and developed, and is being in-field tested for domestic lighting.

Indian sugar mills are rapidly turning to bagasse, the leftover of cane after it is crushed and its juice extracted, to generate electricity. This is mainly being done to clean up the environment, cut down power costs and earn additional revenue. According to current estimates, about 3500 MW of power can be generated from bagasse in the existing 430 sugar mills in the country. Around 270 MW of power has already been commissioned and more is under construction.

Fuel cells are electrochemical devices that convert the chemical energy of a fuel directly and very efficiently into electricity (DC) and heat, thus doing away with combustion. The most suitable fuel for such cells is hydrogen or a mixture of compounds containing hydrogen. A fuel cell consists of an electrolyte sandwiched between two electrodes. Oxygen passes over one electrode and hydrogen over the other, and they react electrochemically to generate electricity, water, and heat.

Fuel cells

Though fuel cells have been used in space flights and combined supplies of heat and power, electric vehicles are the best option available to dramatically reduce urban air pollution. Compared to vehicles powered by the internal combustion engine, fuel-cell powered vehicles have very high energy conversion efficiency, (almost double that of currently used engines) and near-zero pollution, CO2 and water vapour being the only emissions. Fuel-cell-powered EV's (electric vehicles) score over battery operated EV's in terms of increased efficiency and easier and faster refueling.

Fuel cells for power generation – India has a large gap between the demand for and supply of power. Conventional large-scale power plants use non-renewable fuels with significant adverse ecological and environmental impacts. Fuel cell systems are excellent candidates for small-scale decentralized power generation.

The energy in the flowing water can be used to produce electricity. Waves result from the interaction of the wind with the surface of the sea and represent a transfer of energy from the wind to the sea. Energy can be extracted from tides by creating a reservoir or basin behind a barrage and then passing tidal waters through turbines in the barrage to generate electricity.

Hydel Energy

New environmental laws affected by the danger of global warming have made energy from small hydropower plants more relevant. These small hydropower plants can serve the energy needs of remote rural areas independently. The real challenge in a remote area lies in successful marketing of the energy and recovering the dues. Local industries should be encouraged to use this electricity for sustainable development.

It is a technology with enormous potential, which could exploit the water resources to supply energy to remote rural areas with little access to conventional energy sources. It also eliminates most of the negative environmental effects associated with large hydro projects.

We live between two great sources of energy, the hot rocks beneath the surface of the earth and the sun in the sky. Our ancestors knew the value of geothermal energy; they bathed and cooked in hot springs. Today we have recognized that this resource has potential for much broader application

Geothermal Energy

In India, Northwestern Himalayas and the western coast are considered geothermal areas. The Geological Survey of India has already identified more than 350 hot spring sites, which can be explored as areas to tap geothermal energy. Satellites like the IRS-1 have played an important role, through infrared photographs of the ground, in locating geothermal areas. The Puga valley in the Ladakh region has the most promising geothermal field. An experimental 1-kW generator is already in operation in this area. It is being used mainly for poultry farming, mushroom cultivation, and pashmina-wool processing, all of which need higher temperature.

Wind energy is the kinetic energy associated with the movement of atmospheric air.

India ranks 5th in the world with a total wind power capacity and our present utilization is only 26 TW-h/year. We are having vast stretch of sea shore on both sides where wind is blowing throughout the year which has to be harnessed to our advantage. The present increasing utilization of wind energy is highly supplementing our energy requirements.

Wind Energy

Five nations – Germany, USA, Denmark, Spain and India – account for 80% of the world’s installed wind energy capacity. Wind energy continues to be the fastest growing renewable energy source with worldwide wind power installed capacity is ever increasing.

We have to accelerate the pace of growth in utilizing wind energy which is cheaper and technologically more feasible. It is worth while to mention here that our state is taking a leading role in utilizing wind energy. Hence Indigenous research has to be encouraged for cost effective utilization of wind energy.

The other forms of renewable energy is also to be encouraged to supplement the total energy requirements and for the benefit of our farming community. India is heavily depending on agriculture and utilization of energy from bio waste locally will go a long way in enhancing the agricultural production and improving the quality of life of our farmers.

With this I conclude that renewable energy is the ultimate energy for sustaining human life in this planet. I exhort the technocrats and scientists of our nation to channelize their research and effort in this direction.

Many of the present problems such as wastage in transmission, energy loss, grid interactive and efficient power management is another area where we have to concentrate for energy saving and utilization.

We may even find out the possibilities of combining the difference sources of renewable energy into a hybrid energy which will be cost effective in generation & transmission. When such energy is generated in each establishment indigenously that will meet the energy requirements independently without depending on external sources such as EB and other conventional energy generating units.