# Comparing power output of Solar Panels/cells

jonnyrocks

## Homework Statement

The task is to compare the power outputs of solar cells, and solar panels. For solar cells, a circuit is devised to work out the power, solar panels a beaker of water is heated.

## Homework Equations

Power=voltagextime
Q=mc(delta)T
Power=Energy/time

## The Attempt at a Solution

Here is a scan of my two circuits at the moment
(The link is in my signature, it won't let me post it here ;) 0
For the solar cell, i will use the voltmeter and ammeter to work out the power. However, not sure if a resistor is nnecessary, will it affect the measured output power?

Also, how would I make the experement more accurate? I've already got mirrors to reflect as much light as possible, but would making thew beaker black absorb more light? Aditionally, am I right in thinking that 100g of water = 100ml?

Finally, would I have to multiply the powewr output for the cells by the length of time the solar panel is heating?

Thanks very much!

jonnyrocks
Heres the scan:

#### Attachments

• 111062.jpg
46.3 KB · Views: 361
kamerling
To measure the the output of the solar cell you have to connect a load and measure the current that goes through it and the voltage across it. You have to try different resistances as load to see what the value of the load resistance is that maximizes the power.

Energy = Power * Time, so you do have to multiply the power of the solar cell to compare it to the heat added to the water.

alister
Hi,

Solar cells generate an electrical current when light hits their surface. White light that we see from the Sun includes all colors of the visible spectrum and ranges in wavelength from about 400 nanometers (nm) to about 780 nm. Solar cells vary in their response to different wavelengths, or color, of light.

A solar panel will output different levels of power depending on the color and wavelength of the incoming light.