Solar panels of the same size may produce variable amounts of electricity - this discrepancy arises from variations in the functioning age of the solar cells, the quality of the solar cells, and with what technology they were produced. Early solar cells, for example, are not quite as efficient as modern solar cells, so you'll find that with a trusted solar panel manufacturer, quality increases as the technology involved becomes more advanced and precise.
As another example, two identical solar cells are purchased. One is left in storage and the other has been in use for three years. Solar panels have an effective lifespan of about 20 to 25 years, and their value and wattage output decrease steadily over time. The solar cell that has been in storage will be more valuable than one that has been actively converting sunlight to electricity for a long time.
In summary, although two solar panels may seem identical, there are a number of other factors you need to take into consideration. Just because a given solar cell is more expensive per square centimeter than another solar cell, it does not mean that the second one is a bargain. Quality, age, and technology all play a role in the cost of the solar cell.
The best way to compare the value of two solar cells is to measure the dollars/watt ratio. The current best deals on solar cells is about $4.30 per watt. For a 50 watt solar panel, your total cost will be about $215. Keep this in mind when asesssing the cost and purchasing solar cells and panels.
Newer panels may or may not be more cost effective for you, if you have ample mounting space for your solar panel, size shouldn't be a problem, so if you find that you are able to use more primitive technology for a cheaper dollar/watt price, go with it. You will save money for a marginal increase in mounting space. (this usually shouldn't be a problem)
Using scrap solar cells can save you a considerable amount on your solar panel investment. Scrap solar cells are those broken during manufacturing, and solar cell producers often sell these for very cheap prices, and if you solder them together yourself, you can start generating electricity at prices considerably below $3/watt. You can find more information on scrap solar cells from your solar cell manufacturer, and you can purchase scrap solar cells online from various retailers. Scrap solar panels are most useful for those who:
Here at Solar Panel Info.com, we don't directly sell solar panels, but a quality online retailer is the long-standing Mr Solar.com, and you can find other excellent solar panel deals at at the Amazon online store