Solar Global

                          There's noting new under the SUN

   

Thomas Edison.. 

  we are like tenant farmers chopping down the fence around our house for fuel when we should be using Nature's inexhaustible sources of energy -- SUN, wind and tide. ... I'd put my money on the sun and solar energy. What a source of power! I hope we don't have to wait until oil and coal run out before we tackle that.

a New silicon p-n Junction Photocell for Converting Solar Radiation into Electrical Power

 

Solar Energy and Future

 

As the power demand is going on increasing day-by-day, is responsible for our engineers to make it available as per the demand. Many of the power generating plant are using non-renewable sources as their primary source. But these may become extinct at any time and before facing the situation we have to choose an alternatives  is choosing Non-conventional sources like (Solar Energy  Wind Energy Tidal Energy Bio-mass Energy etc..,) as the primary sources for power generation in power stations. The power from these sources is several times greater than the one, which we are using at the present. Out of these energy sources, the best one which suits for our county is the Solar Energy.

Source of Solar Energy

SUN as far back 5,000 years ago, people "worshipped" the sun. We know today, that the sun is simply our nearest star. Without it, life would not exist on our planet. We use the sun's energy every day in many different ways. Indirectly, the sun or other stars are responsible for ALL our energy. Even nuclear energy comes from a start because the uranium atoms used in nuclear energy were created in the fury of nova -a star exploding.

Solar Energy can be converted into other forms of energy, such as heat and electricity. In the 1830s, the British astronomer John Herschel used a solar thermal collector box -a device that absorbs sunlight to collect heat- to cook food during an expedition to Africa. Today, people use the sun's energy for lots of things. Solar energy can be used to heat a fluid such as water in solar collector panels. Simple types use flat collector panels mounted on a south-facing roof or wall, each with transparent cover to admit sunlight. water circulates through channels or popes inside each panel. The inside is usually painted black, because black surfaces readily absorb heat. The water is heated, and then the hot water is pumped to a heat ex-changer that extracts the heat for used to generate electricity in Photovoltaic (PV) cells. A PV cell may power your calculator. Photovoltaic cells are made of semiconductors, similar to those used to make computer chips. Until recently these cells were very costly to produce. However, they are still only about 10-15 per cent efficient.

Photovoltaic Cell

Photovoltaic is the direct conversion of light into electricity at the atomic level. Some materials exhibit a property known as the photoelectric effect that causes them to absorb photos of light and release electrons. When these free electrons are captured, an electric current results that can be used as electricity.

 

The photoelectric effect was first noted by a French physicist, Edmund Bequerel, in 1839, who found that certain materials would produce small amounts of electric current when exposed to light. In 1905. Albert Einstein described the nature of light and the photoelectric effect on which photovoltaic technology is based, for which he later won a Nobel Prize in physics. The first photovoltaic module was built by Bell Laboratories in 1954. It was billed as a solar battery and was mostly just a curiosity as it was too expensive to gain widespread use. In the 1960s, the space industry began to make the first serious use of the technology to provide power aboard spacecraft. Through the space programs, the technology advanced, its reliability was established, and the cost began to decline. During the energy crisis in the 1970s, photovoltaic technology gained recognition as a source of power for non-space applications.

Solar Thermal Power Plant:

There are tow types of solar thermal power plants.

                                 1.Solar distributed collector power plants

                                 2.Solar central receiver power plants

In this types of power plants, collectors are used. A very large area is required. The collectors may be of following types.

                                1.Parabolic through units with line focus.

                                2.Paraboloidal dishes with central focus.

Parabolic through collectors are preferred because of low cost of manufacture and simple single plane sun-tracking. Where as in paraboloidal collectors use double plane sun-tracking and are expensive.Nevada solar one is a new solar thermal plant with a 64 MW generating capacity, located near Boulder City, Nevada. Solar one uses parabolic troughs as thermal solar concentrators, heating tubes of liquid which act as solar receivers. These solar receivers are specially coated tubes made of glass and steel, and about 19,300 of these four meter long tubes are used in the newly built power plant. Solar energy be called upon to play a much larger role in the global energy system by min-century... 

 

 Future solar deployment will depend heavily on uncertain future market conditions and public policies -- including but not limited to policies aimed at mitigating global climate change.

This people is motivated by the enormous potential of solar energy as a tool to reduce global CO2 emission and the great importance of effecting those reductions.

The difficulties of integrating large--scale solar generation into electric power systems derive from a fundamental characteristic of the solar resource: its intermittency.

Within and between days, rapid and relatively unpredictable variations in irradiance can arise from shifting cloud cover.

There are emerging technologies with considerable promise that use Earth--abundant materials and that could be deployed at large scale if their efficiency and stability could be dramatically improved.

The coordination of solar energy production and storage, through thermal storage at CSP facilities or through other means, can also help reduce the need for thermal-plant cycling and thereby increase the value of solar generation.

 

The division of any given level of spending between deployment and RD&D should be heavily influenced by expectations about the determinants of long-term costs.

 

Federal, state, and local policies that subsidize residential solar generation more generously than utility-scale solar generation make little sense.

         

Solar photovoltaics are the most widely deployed solar electric technology in the world today.

 

Present crystalline silicon technologies could achieve terawatt-scale deployment by 2050 without major technological advances.

 

CSP has a range of characteristics that make it an attractive power generation pathway.

 

Developing a commercial CSP plant requires a very large capital investment and presents financial risks that only a limited set of investors are capable to taking on.

 

One important limitation is that the LCOE implicitly values all kilowatt-hours of power produced the same, regardless of when they are generated. But the incremental cost of meeting electricity demand is higher during peak periods.

In a system with lots of solar generators that can profitably sell power in the short run at almost any positive price, wholesale price might be lower at noon than at midnight.

Several aspects of joint production make the demand-price function for by produced energy-critical elements (ECEs) volatile and difficult to predict.

Alternative approaches should aim to incentivize efficient responses by network users using a system of charges and credits that is consistent with sound principles of coat causality.

As solar penetration grows, the net load peak progressively decreases, narrows and shifts in time.

In the absence of  a comprehensive policy, subsidizing solar deployment may be justified as part of a second-best CO2 reduction policy.

Finding an appropriate and effective balance in government efforts to support solar technologies is a difficult but crucially important task.

Total DOE funding for solar energy research has fluctuated from year to year, often significantly.

The application of new high-capacity electrode materials, optimization of electrode coating thicknesses, and improvements in manufacturing are expected to play a major role in bringing down costs in the future!