Solar power – Energy that is most sustainable to protect our economy and environment:

Solar power – Energy that is most sustainable to protect our economy and environment:

Originally developed for energy requirement for orbiting earth satellite - Solar Power – have expanded in recent years for our domestic and industrial needs. Solar power is produced by collecting sunlight and converting it into electricity. This is done by using solar panels, which are large flat panels made up of many individual solar cells. It is most often used in remote locations, although it is becoming more popular in urban areas as well.

There is, indeed, enormous amount of advantages lies with use of solar power specially, in the context of environmental impact and self-reliance. However, a few disadvantages such as its initial cost and the effects of weather conditions, make us hesitant to proceed with full vigor. We discuss below the advantages and disadvantages of Solar Power:

Advantages -

(a) The major advantage of solar power is that no pollution is created in the process of generating electricity. Environmentally it the most Clean and Green energy. Solar Energy is clean, renewable (unlike gas, oil and coal) and sustainable, helping to protect our environment.

(b) Solar energy does not require any fuel.

(c) It does not pollute our air by releasing carbon dioxide, nitrogen oxide, sulfur dioxide or mercury into the atmosphere like many traditional forms of electrical generation does.

(d) Therefore Solar Energy does not contribute to global warming, acid rain or smog. It actively contributes to the decrease of harmful green house gas emissions.

(e) There is no on-going cost for the power it generates – as solar radiation is free everywhere. Once installed, there are no recurring costs.

(f) It can be flexibly applied to a variety of stationary or portable applications. Unlike most forms of electrical generation, the panels can be made small enough to fit pocket-size electronic devices, or sufficiently large to charge an automobile battery or supply electricity to entire buildings.

(g) It offers much more self-reliance than depending upon a power utility for all electricity.

(h) It is quite economical in long run. After the initial investment has been recovered, the energy from the sun is practically free. Solar Energy systems are virtually maintenance free and will last for decades.

(i) It's not affected by the supply and demand of fuel and is therefore not subjected to the ever-increasing price of fossil fuel.

(j) By not using any fuel, Solar Energy does not contribute to the cost and problems of the recovery and transportation of fuel or the storage of radioactive waste.

(k) It's generated where it is needed. Therefore, large scale transmission cost is minimized.

(l) Solar Energy can be utilized to offset utility-supplied energy consumption. It does not only reduce your electricity bill, but will also continue to supply your home/ business with electricity in the event of a power outage.

(m) A Solar Energy system can operate entirely independently, not requiring a connection to a power or gas grid at all. Systems can therefore be installed in remote locations, making it more practical and cost-effective than the supply of utility electricity to a new site.

(n) The use of solar energy indirectly reduces health costs.

(o) They operate silently, have no moving parts, do not release offensive smells and do not require you to add any fuel.

(p) More solar panels can easily be added in the future when your family's needs grow.

(q) Solar Energy supports local job and wealth creation, fuelling local economies.

Disadvantages –

(a) The initial cost is the main disadvantage of installing a solar energy system, largely because of the high cost of the semi-conducting materials used in building solar panels.

(b) The cost of solar energy is also high compared to non-renewable utility-supplied electricity. As energy shortages are becoming more common, solar energy is becoming more price-competitive.

(c) Solar panels require quite a large area for installation to achieve a good level of efficiency.

(d) The efficiency of the system also relies on the location of the sun, although this problem can be overcome with the installation of certain components.

(e) The production of solar energy is influenced by the presence of clouds or pollution in the air. Similarly, no solar energy will be produced during nighttime although a battery backup system and/or net metering will solve this problem.

(f) As far as solar powered cars go - their slower speed might not appeal to everyone caught up in today's fast track movement.

Conclusion - Solar power technology is improving consistently over time, as people begin to understand the benefits offered by this incredible technology. As our oil reserves decline, it is important for us to turn to alternative sources for energy. Therefore, it would be better that converting some of the world's energy requirements to solar power are in the best interest of the worldwide economy and the environment. Since we all are aware of the power of the sun and the benefits we could get from it.

Solar Power – Development in new technology making it economically competitive:

Solar Power – Development in new technology making it economically competitive:

We all know that solar power is excellently exciting. Just lay down a sheet or a panel exposing sun and every day, for the life of the device, you get free power. There are no fuel costs, no running or maintenance cost. It is a renewable resource, meaning no end of raw material. Therefore, we do not have to worry about the sun ever going away. Although the sun may disappear behind a few clouds for a few minutes, disappear completely at night, or for hours during the winter, we can always expect it to come back in full force. Apart, solar power is non-polluting. Unlike oil, solar power does not emit any greenhouse gases or carcinogens into the air. Solar power is good for the environment and make our atmosphere clean. Solar power is silent powered also, i.e., no noise pollution.

There are so many advantages of solar power that it is amazing that it is not yet more common. Perhaps the main reason for this is that at the onset, solar power can be expensive. Unfortunately, the size of the initial investment keeps the cost of solar generated power higher than the cost of coal. At this juncture it is worth noting that, if you take into account the environmental costs of burning coal, solar power is already slightly more economically sound. But we're not taxing carbon (yet) so we've got to make solar power cheaper. Of course, solar cells are not cheap. However, technology for this is improving, and it will continue to improve as the cost of other forms of power increase. There are few of the finest examples that are working to bring solar power to grid parity. Some of these useful technologies are briefed below:

1. The most expensive part of a traditional photovoltaic array is the silicon wafers. To solve this cost problem (and also the problem of the environmentally wasteful process of creating the silicon crystals) several people are concentrating the sunlight thousands of times onto an extremely small solar panel. They decrease the amount of solar material needed by thousands of times, and produce just as much power.

Technologies collectively known as concentrating photovoltaic are starting to enjoy their day in the sun, thanks to advances in solar cells, which absorb light and convert it into electricity, and the mirror- or lens-based concentrator systems that focus light on them. The technology could soon make solar power as cheap as electricity from the grid. The idea of concentrating sunlight to reduce the size of solar cells - and therefore to cut costs -has been around for decades. The result is solar power that is nearly as cheap (if not as cheap) as coal.

The thinking behind concentrated solar power is simple. Because energy from the sun, although abundant, is diffuse, generating one gigawatt of power (the size of a typical utility-scale plant) using traditional photovoltaic requires a four-square-mile area of silicon. A concentrator system would replace most of the silicon with plastic or glass lenses or metal reflectors, requiring only as much semiconductor material as it would take to cover an area of much smaller in size. Moreover, because of decrease in the amount of semiconductor needed makes it affordable to use much more efficient types of solar cells. The total footprint of such plant, including the reflectors or lenses, would be only two to two-and-a-half square miles.

The big problem of this technology is very hot piece of silicon. You have to keep the silicon cool, even with sunlight magnified 2000 times on it. Otherwise the silicon will melt, and it's all over. Scientists are working prototypes already and are hoping to go commercial in the coming years.

2. Another solution to the problem of limited and expensive crystalline silicon is to just not use it. This is why there are so many solar startups right now working on solar technology using non-crystalline silicon or other thin-film solutions. Many have already broken out of the lab and into manufacturing. One of the leading technologies, not using expensive crystalline silicon is ‘Nano-solar’ prints. Nano-solar prints it's mixture of several elements in precise proportions onto a metal film. The production is fast, simple and cheap, at least for now. Some fear that shortages in indium will bring a halt to nano-solar's cheap printing days. Though scientists make some efficiency sacrifices when compared to crystalline silicon, they are so much cheaper to produce that they might soon even beat coal in cost per watt.

The advantages of ‘Nano-solar’ prints are, they are super cheap, ultra-adaptable solar panels that can be printed on the side of pretty much anything, promising solar power anywhere you want it. At the present condition, they still slide under coal's $2.1-a-watt energy cost, though they're not mass produced at the scale needed to bring it to the 30-cents-a-watt level.

3. While the first two options provide the most efficient path to solar electricity, but converting photons directly into electrons, a less efficient, though simpler, option might turn out to be the real cost-effective. Simply by focusing hundreds or even thousands of mirrors onto a single point, scientists are hoping to create the kind of heat necessary to run a coal fired power plant, but without use of coal. The heat would boil water which would then be used to turn turbines. In other words, it is nothing but, concentrated thermal solar power, which concentrates the heat from the sun to power turbines or sterling engines.

The advantage of such a system is converting the existing steam turbines being produced for traditional power plants, and the rest of the technology just involves shiny objects and concrete. The problems however, are these things too hot to handle. The material holding the boiler has to be able to withstand the extreme heat that these installations can produce. That kind of material, that won't melt or degrade under such extreme heat, can be quite expensive.

Methane from Biogas - A renewable source of green energy to be encouraged to generate:

Methane from Biogas - A renewable source of green energy to be encouraged to generate:

Anaerobic digestion of wastes provides biogas. Biogas contains about 60% methane that can be used to generate electricity or used for heat or for fuel for vehicles. Any animal manure, human sewage or food waste will produce methane during anaerobic digestion. Natural gas is methane. Biogas can be "cleaned" to yield purified methane that can be used in the natural gas pipelines.

Methane from biogas is an excellent alternative energy source. Using methane for energy helps the environment by replacing the use of non-renewable fossil fuels with renewable energy. Methane is a green house gas that has 21 times the heating effect as carbon dioxide. Biogas methane is renewable unlike natural gas which is mined from underground wells and is a non-renewable fossil fuel. Methane biogas is about to become much more important as an energy source than it has been in the past, due to the ever rising cost of natural gas.

A. Some facts about methane biogas –

(a) Millions of cubic metres of methane in the form of swamp gas or biogas are produced every year by the decomposition of organic matter, both animal and vegetable.

(b) It is almost identical to the natural gas pumped out of the ground by the oil companies and used by many of us for heating our houses and cooking our meals.

(c) Many countries have for years been steadily building anaerobic digestion facilities for generating electricity from methane produced from manure, sewage and garbage.

(d) Villagers in many undeveloped countries use very simple technology to convert animal and human wastes to biogas for cooking and heating.

(e) Recently hundreds of farms in Mexico and South America have installed anaerobic digesters to collect and use methane from manure to provide energy for farm use. Many of these digesters have been paid for by a company that aggregates and sells carbon credits to factories and utility companies in countries that signed agreements under the Kyoto protocol to reduce greenhouse emissions. Carbon credits are earned by reducing greenhouse gas emissions such as carbon dioxide and methane. These credits have considerable value.

(f) In the U.S., which rejected the Kyoto protocol, most of the methane from wastes is allowed to escape into the atmosphere where it contributes to global warming. However there are about a hundred or so dairy farms, a few pig farms, some landfills and a few municipal sewage treatment plants in the U.S. that are collecting methane from waste and using it for fuel.

B. Unbelievable as it may seem, at this time of approaching energy crisis, most farmers can’t get utility companies to purchase their green, renewable electricity. Possible reasons for this reluctance on the part of electrical utilities range from lack of familiarity with connecting farm generators to pressure from coal and oil companies to maintain monopoly of the utility market. Without the ability to sell the excess power generated
from methane farmers or others with sources of methane can’t afford to install the equipment for collecting methane and generating power as this usually means an investment of a million or more dollars.

C. This kind of situation needs change. Countries where the production of methane from biogas is not practiced, realizing the seriousness of global warming and problems associated with fossil fuel usage, “green energy” generated from sources such as wind, biomass and, in a few cases, bio-methane are to be encouraged by law. Moreover, consumer pressure will likely be needed to motivate more electric utilities to purchase electricity generated from renewable methane thus ensuring energy security.

D. Biogas from manure or other wastes can be purified to yield pipeline grade methane. With the increase in price of natural gas it has become economically feasible in some cases to remove impurities from the methane and sell it to companies supplying natural gas (methane is chemically the same as natural gas). Due to the energy that must be used to clean, compress and transport the gas this is usually not as efficient a route for using methane as feeding it directly into a generator but, unless electric utility companies become willing to pay a fair price for electricity generated from farm methane, selling gas for pipeline use may become a more common practice.

Wind Energy – Renewable energy by harnessing wind power – Answer for Emission problem:

Wind Energy – Renewable energy by harnessing wind power – Answer for Emission problem:

People try to make many assumptions against wind turbines for generation of wind energy; but the fact remains, wind energy is most suitable form of renewable energy we can have to replace coal fired / nuclear powered / and even oil fired power plants in the near future. In support various points are discussed below:

1. Wind power is a clean, renewable source of energy which produces no greenhouse gas emissions or waste products. Power stations are the largest contributor to carbon emissions, producing tones of CO2 each year. We need to switch to forms of energy that do not produce CO2. Just one modern wind turbine will save over 4,000 tones of CO2 emissions annually.

2. The average wind farm will pay back the energy used in its manufacture within 3-5 months of operation. This compares favorably with coal or nuclear power stations, which take about six months.

3. A modern wind turbine is designed to operate for more than 20 years and at the end of its working life, the area can be restored at low financial and environmental costs. Wind energy is a form of development which is essentially reversible – in contrast to fossil fuel or nuclear power stations.

4. A modern wind turbine produces electricity 70-85% of the time, but it generates different outputs depending on the wind speed. Over the course of a year, it will typically generate about 30% of the theoretical maximum output. This is known as its load factor. The load factor of conventional power stations is on average 50%. A modern wind turbine will generate enough to meet the electricity demands of more than a thousand homes over the course of a year.

5. All forms of power generation require back up and no energy technology can be relied upon 100%. Variations in the output from wind farms are barely noticeable over and above the normal fluctuation in supply and demand.

6. The cost of generating electricity from wind has fallen dramatically over the past few years. Between 1990 and 2007, world wind energy capacity doubled every three years and with every doubling prices fell by 15%. Wind energy is competitive with new coal and new nuclear capacity, even before any environmental costs of fossil fuel and nuclear generation are taken into account. As gas prices increase and wind power costs fall – both of which are very likely – wind becomes even more competitive, so much so that some time after 2010 wind should challenge gas as the lowest cost power source. Furthermore, the wind is a free and widely available fuel source, therefore once the wind farm is in place, there is no fuel requirement or no waste related costs.

7. In future, we will need a mix of both onshore and offshore wind energy to meet the challenging targets on climate change. At present, onshore wind is more economical than development offshore. However, more offshore wind farms are now under construction. Thus, prices will fall as the industry gains more experience.

8. Wind energy is a benign technology with no associated emissions, harmful pollutants or waste products. In over 25 years and with more than 75,000 machines installed around the world, and there is no report of any body has ever been harmed by the normal operation of wind turbines.

9. The evolution of wind farm technology over the past decade has rendered mechanical noise from turbines almost undetectable with the main sound being the aerodynamic swoosh of the blades passing the tower.

10. We need to act now to find replacement power sources - wind is an abundant resource, and therefore has a vital role to play in the new energy portfolio all over the world.

Average onshore turbines discussed here is of capacity 1.8 MW. For many on-going projects at present the capacity over 2 MW turbines are being installed. Offshore, turbines currently being installed are rated at 3 MW, and it is expected that this will rise to a typical 5 MW per machine by 2010.