Energy Mix Strategies for oil importing country – Important in the scenario of energy security and global warming:

Energy Mix Strategies for oil importing country – Important in the scenario of energy security and global warming:

A. We are aware of the problems of environmental pollution and the adverse consequences of global warming causing due to CO2 emission. To restrict environmental pollution, to mitigate the CO2 emission and rate of increase of CO₂ concentration in the atmosphere, responsive long term energy mix strategies exploiting the maximum potential of non-greenhouse gas emitting energy sources need to be developed and implemented as rapidly as possible. The future energy mix will not only depend on environmental issues, but also will depend on technological, economic, supply, logistics and political factors. It is generally accepted that for many decades fossil fuels will continue to be the major energy source world over. Natural gas being the lowest fossil fuel greenhouse gas emitter will increase the share in energy scenario world over. Countries having or exporting fossil fuels cannot easily turn away from their use and likewise the industrially & economically dynamic countries of Asia such as China, Japan and India cannot radically shift from fossil fuels towards uncertain and currently costly renewable for their growing power needs.

B. National and regional factors are the most important in guiding country's energy mix. Percentage share of energy differ considerably today and they will in the future. For example, today China is more than 90% dependent on various forms of fossil fuels. On the other hand, France and Sweden have reduced their dependence on fossil fuels to less than 50% and 35% respectively by using nuclear and hydro-power to a great extent. Moreover, out of all the fossil fuels coal is the workhorse of global electric power sector and is used to generate more than half of the electricity world consumes. Coal is also world’s most abundant fossil fuel, with supplies projected to last almost 250 years or more. As coal-fired power plants generally produce the lowest-cost electricity and coal is abundant, most of the country’s economic and energy security depend on the continued use of the fuel.

C. Therefore, on the global level, it is difficult to make a policy decisions to foster a reduced reliance on fossil fuel. Decision makers are confused on how to proceed for country’s energy mix for the future as there is general support for cost effective energy efficiency techniques and on the supply side an endorsement of an increased use of renewable and sustainable energy sources. In fact, both the efforts are necessary at present; but ‘renewable and sustainable energy sources’ have limited potential over the near term. However, in the developed and industrialized countries, the significant energy efficiency gains and use of renewable energy sources have been seen over the past two decades, that changed the dependence on fossil fuels and energy scenario to a great extent on their industrial and residential front.

D. The supply potential from renewable energy sources, at present, is difficult to assess since they are only emerging technologies and currently not suitable for meeting large energy demand of a country. With differing relevance for the various renewable energy sources, technological improvements are needed and basic challenges exist in reducing costs, improving efficiency and reliability, solving energy storage problems and integrating the technologies into existing energy systems. In most of the developed countries many decision makers in the opinion that, non-hydroelectric renewable energy sources, such as solar and wind will not be economically competitive for large scale production in the foreseeable future and that they will play no more than a limited role in the decades to come. They opine that, even with adequate support and subsidies the share of such renewable energy sources could reach only 5-8% (including about 3% non-commercial energy share) of primary energy supply by 2020.

E. Fortunately, hydroelectric has already been extensively developed and in use in Europe and North America (some 50% of the estimated maximum economic potential). Its greatest potential lies primarily in Asia, South America and Africa, where the trend will likely be towards small capacity units as concerns grow about the damaging environmental and social impacts of large dams.

F. Energy security and implementing proper energy mix strategies for oil importing countries are very much crucial especially in the scenario of rapid industrialization. For those countries, in my opinion, renewable energy must be developed in parallel with nuclear power and a clean-up of coal-fired power station technology, if these nations are to meet increasing demand without relying on enormous and potentially debilitating natural gas imports. For a nation the provision of sufficient, affordable and secure energy is crucial for any modern economy. Many countries are facing the challenge of bridging the widening gap between energy supply and demand. At the same time, across the globe, those same economies are facing challenges such as climate change, limited resources and rising costs. Therefore, for oil importing countries, energy mix should shift more towards, nuclear power and clean coal technology.

G. There are very large amounts of remaining oil, gas and coal left in the world and in the absence of concerted government initiatives, it may take many years before alternative energy sources such as wind and solar become a significant part of the world’s energy mix. It is true that some renewable sources such as bio-fuels and wind have attained ten-fold production increases throughout the past ten years. However, global energy demand is increasing at such a rate that, if we ignore hydro-electricity, renewable energy - as a proportion of total energy supply - may well remain at less than 2 per cent of the total market for many years to come. It may be noted here that, global climate change may be best addressed in the short term by energy conservation, by increasing fuel efficiency, and by subsurface storage of the carbon dioxide that results from burning fossil fuels. At the same time, the greatest advantages of nuclear power is that it avoids the wide variety of environmental problems arising from burning fossil fuels, apart from economically generating a high amount of electrical energy in one single plant using small amount of fuel.

H. Therefore, concerted efforts by such economies, in order to have secured energy for their sustainable developments, should involve large scale nuclear expansion, the development of clean coal-fired power stations, implementation of hydro-electric power to maximum potential and a increase in renewable energy sources such as solar and wind.

Renewable energy is green energy:

Renewable energy is green energy:

Renewable energy is the energy which is made from resources that Mother Nature replaces, such as wind, water and sunshine. Renewable energy is also called “clean energy” or “green power” because it doesn’t pollute the air or the water. In fact, wind, water and sunshine are the cleanest and most abundant sources of energy we have.

However, these abundant and natural sources of renewable energy have few shortcomings, such as unlike natural gas and coal, we can’t store up wind and sunshine to use whenever we need to make more electricity. If the wind doesn’t blow or the sun hides behind clouds, there wouldn’t be enough power for everyone. Another reason why we prefer fossil fuels like coal and natural gas over natural sources of energy is because they’re cheaper. It costs more money to make electricity from wind, and most people aren’t willing to pay more on their monthly utility bills.

The prominent sources of renewable energy are: (i) Wind power, (ii) Biomass energy, (iii) Hydro power, (iv) Solar power, (v) Geothermal energy.

(i) Wind Power - Here a wind turbine is used to make electricity. Using the wind to create electricity has been around for a long time. When the wind turns the blades of a windmill, it spins a turbine inside a small generator to produce electricity, just like a big coal power plant. To make enough electricity to serve lots of people, power companies build "wind farms" with dozens of huge wind turbines. Wind farms are built in flat, open areas where the wind blows at least 14 miles per hour.

(ii) Biomass Energy - Biomass energy uses natural materials like trees and plants to make electricity. It can also mean waste products like trash. Biomass means "natural material." When biomass energy is burned, it releases heat – just like the wood logs in your campfire. Some of the common material used includes: (a) Leftover wood from sawmills. (b) Leftover paper and wood waste from paper mills. (c) Corn stalks, corn cobs and seed corn from farms. (d) Paper and cardboard that can’t be recycled in other ways. (e) Fast-growing crops and trees etc.

The philosophy behind biomass energy includes:

* Growing energy crops,

* Turning garbage into energy,

* Cow power or power from animal waste.

(iii) Hydro Power - A hydro power plant uses river water to make electricity. In fact, people have used water power for more than 2,000 years. In modern day, people built dams to control the power of the big mountain rivers. Workers can change the amount of water flowing through the dam depending on the weather and how much electricity people need.

(iv) Solar Power - “Solar” is the Latin word for “sun” – and it’s a powerful source of energy. In fact, the sunlight that shines on the Earth in just one hour could meet world energy demand for an entire year. We can use solar power in two different ways: (a) as a heat source, and (b) as an energy source.

Today we use solar collectors for heating water and air in our homes. We can also use solar energy to make electricity. The process is called photovoltaics. It’s difficult and expensive to make a lot of electricity using photovoltaics – the panels cost a lot, and a lot of open land is needed.

(v) Geothermal Energy - The hot lava from a volcano and the hot steam from a geyser both come from underground heat - and we can use that same type of heat in our homes. The system pumps a liquid through the pipes to absorb the heat and brings it back indoors. A device called a "heat exchanger" takes the heat from the liquid and uses it to heat the air inside the home. A geothermal system can cool your house during the summer, too! It just works in reverse, absorbing the heat from the air inside your home and moves it back into the earth. A geothermal heater is also very energy-efficient. Almost none of the energy used is wasted, so it helps keep heating bills very low during the winter.

Solar Cell – Renewable and Cleanest Energy Source:

Solar Cell – Renewable and Cleanest Energy Source:

Solar cell is a semiconductor device that converts the energy of sunlight into electric energy. These are also called ‘photovoltaic cell’. Solar cells do not use chemical reactions to produce electric power, and they have no moving parts.

Photovoltaic solar cells are thin silicon disks that convert sunlight into electricity. These disks act as energy sources for a wide variety of uses, including: calculators and other small devices; telecommunications; rooftop panels on individual houses; and for lighting, pumping, and medical refrigeration for villages in developing countries. In large arrays, which may contain many thousands of individual cells, they can function as central electric power stations analogous to nuclear, coal-, or oil-fired power plants. Arrays of solar cells are also used to power satellites; because they have no moving parts that could require service or fuels that would require replenishment, solar cells are ideal for providing power in space.

A. Most photovoltaic cells consist of a semiconductor pn junction, in which electron-hole pairs produced by absorbed radiation are separated by the internal electric field in the junction to generate a current, a voltage, or both, at the device terminals. Under open-circuit conditions (current I = 0) the terminal voltage increases with increasing light intensity, and under short-circuit conditions (voltage V = 0) the magnitude of the current increases with increasing light intensity. When the current is negative and the voltage is positive, the photovoltaic cell delivers power to the external circuit.

B. Characteristics of a Solar Cell - The usable voltage from solar cells depend on the semiconductor material. In silicon it amounts to approximately 0.5 V. Terminal voltages is only weakly dependent on light radiation, while the current intensity increases with higher luminosity. A 100 cm² silicon cell, for example, reaches a maximum current intensity of approximately 2 A when radiated by 1000 W/m². The output (product of electricity and voltage) of a solar cell is temperature dependent. Higher cell temperatures lead to lower output, and hence to lower efficiency. The level of efficiency indicates how much of the radiated quantity of light is converted into useable electrical energy.

C. Cell Types: One can distinguish three cell types according to the type of crystal: monocrystalline, polycrystalline and amorphous. To produce a monocrystalline silicon cell, absolutely pure semiconducting material is necessary. Monocrystalline rods are extracted from melted silicon and then sawed into thin plates. This production process guarantees a relatively high level of efficiency.

The production of polycrystalline cells is more cost-efficient. In this process, liquid silicon is poured into blocks that are subsequently sawed into plates. During solidification of the material, crystal structures of varying sizes are formed, at whose borders defects emerge. As a result of this crystal defect, the solar cell is less efficient.
If a silicon film is deposited on glass or another substrate material, this is a so-called amorphous or thin layer cell. The layer thickness amounts to less than 1µm (thickness of a human hair: 50-100 µm), so the production costs are lower due to the low material costs. However, the efficiency of amorphous cells is much lower than that of the other two cell types. Because of this, they are primarily used in low power equipment (watches, pocket calculators) or as facade elements.

D. Efficiency: Solar cell efficiencies vary from 6% for amorphous silicon-based solar cells to 42.8% with multiple-junction research lab cells. Solar cell energy conversion efficiencies for commercially available multicrystalline Si solar cells are around 14-16%. The highest efficiency cells have not always been the most economical — for example a 30% efficient multijunction cell based on exotic materials such as gallium arsenide or indium selenide and produced in low volume might well cost one hundred times as much as an 8% efficient amorphous silicon cell in mass production, while only delivering about four times the electrical power.

To make practical use of the solar-generated energy, the electricity is most often fed into the electricity grid using inverters (grid-connected PV systems); in stand alone systems, batteries are used to store the energy that is not needed immediately.

E. Advantages of solar energy: Solar cells are long lasting sources of energy which can be used almost anywhere. They are particularly useful where there is no national grid and also where there are no people such as remote site water pumping or in space. Solar cells provide cost effective solutions to energy problems in places where there is no mains electricity. Solar cells are also totally silent and non-polluting. As they have no moving parts they require little maintenance and have a long lifetime. Compared to other renewable sources they also possess many advantages; wind and water power rely on turbines which are noisy, expensive and liable to breaking down.

Rooftop power is a good way of supplying energy to a growing community. More cells can be added to homes and businesses as the community grows so that energy generation is in line with demand. Many large scale systems currently end up over generating to ensure that everyone has enough. Solar cells can also be installed in a distributed fashion, i.e. they don't need large scale installations. Solar cells can easily be installed on roofs, which mean no new space is needed and each user can quietly generate their own energy.

F. Disadvantages of solar cells: The main disadvantage of solar energy is the initial cost. Most types of solar cell require large areas of land to achieve average efficiency. Air pollution and weather can also have a large effect on the efficiency of the cells. The silicon used is also very expensive and the problem of nocturnal down times means solar cells can only ever generate during the daytime. Solar energy is currently thought to cost about twice as much as traditional sources (coal, oil etc). Obviously, as fossil fuel reserves become depleted, their cost will rise until a point is reached where solar cells become an economically viable source of energy. When this occurs, massive investment will be able to further increase their efficiency and lower their cost.