PV Gap

Annette Said:

What is solar cell? where from i can get /purchase and use it on my own application, and how much it cost? and?

We Answered:

I'm not sure what country you're in, but in the US, you can find individual solar cells at

http://www.goldmine-elec-products.com/pr…

But if you were interested in ready-made panels, then just Google "solar panel prices" and you'll see dozens of places offering them.

Pricing for solar panels is about $4 a watt for larger panels, $10 a watt for smaller ones. So a 200-watt panel will cost about $800, and a 10-watt panel will cost about $100. There may be cheaper panels around, but check the warranty. Some types don't last more than a few years. And of course, you can pay much more than these prices depending on where you shop.

Edna Said:

What is the price of solar cell to charge 12V 6Amp battery?

We Answered:

Well the speed with which you want to charge those batteries is a direct relationship to what size solar panels you need. Lot's will do the trick. However, the charge controller you use dictates the voltage limits.

Here is how it works.

Sun --> Panel --> Charge Controller --> Battery

Sun: Varies by time of day....
SO
Panel output: Varies by time of day inclinations etc...
SO
Charge Controller is designed to take a range of voltage that is huge, and normalize it before it goes into the battery. They are pretty efficient, roughly 90%.
THEN
The battery is charged as fast as the electricity comes through, as a battery is a power tank. To make it easy to think about, it is just like a water tank with different rates of incoming water, and the varying amounts of time to fill it up.

The math looks like this.
FIRST: Ohms law (physics)
Watts = Volts x Amps

12 volt, 6ah batteries, and 1 day to charge em.

12v battery @ 6ah = 72watt hours of power in the battery.
If you have 4, and they are half way run down then that looks like this.
12v * 6ah * 4 batteries * 50% dead = 12*6*4*.5 = 144 watt hours

This means you need to produce more than 144 watt hours to charge em up. You have to compensate for the inefficiencies of wires, the charge controller, and the battery, so figure 1.5 that or 216 watt hours to be safe. Go search this site for lots more on the subject: http://www.bdbatteries.com/

So now we calculate how many panels.
Where do you live?
WHY? It dictates how many hours of sun you will get in a day.
6 in the desert southwest, 3-4 in the northeast.
Click on this link to get a rough idea of your own.
http://www.bdbatteries.com/solmaps.php

Finally we divide the total power we need, by the number of hours we have to make it. This decides the array size. At that point we start hunting for panels.

So for our we will use Denver, and an average 5 hours of sun.
Math for the example:
216 watts/ 5 hours of sun = 43.2 watt solar array.
So 1 50 watt solar panel from some manus would do it.
I would get a 60 watt, as we rate panels at .80% for calculations due to real world.

Click here for available solar panels. Concentrate on a cost per watt on the panel. This site even does the math for you.
http://www.bdbatteries.com/solavailable.…
But basically you are looking at $500-$1000 for a good one.

Larry Said:

How much power does a solar cell collect per square foot?

We Answered:

That depends on different factor s
Manufacturer the max efficiency of solar cell is not more than 20% under ideal conditions
The temperature plays a big roll in the efficiency.
Angle of the light on the solar cell panel.
The time of the year because the son is not at the same distance from earth at all times.
Power in watt = currant (amps)*volts cos ?
Usually a solar cell is low voltage 12volte or 24 Volte
One very important thing that with solar cells you can accomplish nothing its so expensive that you will get your capital back after 20 years a 50 watt panel cost around 1000 $ do the math.

Jorge Said:

Project - High school - Solar cell driven battery charger?

We Answered:

A key point to consider in summing up is the cost, covering the break even point for replacing an existing mains charger and in comparison with purchasing an alternative mains charger.

Another issue to keep track of is usability, what if you are not in a sun facing room. Even in ideal conditions, how long will charging take.

Two possible conclusions to try to substantiate:
1. Solar charging is economical and practical unless you have a permanently shaded location.
2. Solar charging is slow expensive, unwieldy and a last resort unless you are unable to access a source of mains power or a 12v in-car charger.

Priscilla Said:

In terms of price, how much is the difference of mono-crystalline and poly-crystalline solar cells?

We Answered:

Here is a comparison. A poly cell:
http://www.spheralsolar.com/sharp80wpvmo…

and a mono cell:
http://www.spheralsolar.com/ae-80he80wat…

Mono cell is slightly higher, I think this holds true of most cells.

Courtney Said:

What percent of Americans have a cell phone?

We Answered:

82% as of 2007. Graph:
http://www.gearlog.com/CTIA_smaller.JPG

Claire Said:

Why are we still not using solar cell?

We Answered:

Are you talking about Solar Energy as the next century of power source?

If so I will tell you. Do you realize that the sun rises and set at a 12 hours interval?

Secondly, in a cloudy day, the solar power station might be only able to supply half the energy REQUIRED?

Thirdly Solar power station needs a large area. But when you put this power station in a desert, a LONG overhead/underground transmissions line is needed. Which will have big power loss over long transmissions.

Cooling- when you installed/construct the power station in a desert, water for the cooling of transformers is scares.