What are solar panels?

Question

plz I need it before 1 August 2008

Answer 1

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.

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Answer 2

There are 2 types of solar panels.

1.  photovoltaic modules use solar cells to convert light from the sun into electricity.

2.  Solar thermal collectors use the sun's energy to heat water or another fluid such as oil or antifreeze.

Answer 3

They receive light from the sun to provide energy to heat your home

Answer 4

simply put: they are panels (hope you know what a panel is) that absorb the sunlight and produce electricity for the household.

They are a great way if you dont wanna harm the enviornment but there not exactly fully reliable.

They only make electricity when there is SUNLIGHT!! =P

and they dont make a lot of electricity because they only convert a very low % of sunlight into electricity. But these days they are getting better.

anyway. i wouldnt recommend installing these in your home as they are quite expensive and not ver efficient except in large numbers.

hope this helps.

wish i could post a picture but dont know how and dont know if its possible. =P

Answer 5

Panels, usually installed on roofs, which use the sun’s energy directly to heat water, without using electricity