# A comparison of the efficiencies of solar cells and solar panels

Leonore Cilliers - 0810                Leighton Park School - 51325

Physics Plan

Solar cells:

Below are diagrams to show how the solar cell will be set up to measure the power output.

The photovoltaic cell circuit will be set up as follows:

The experiment must be completed in complete darkness with the only incident light coming from the 150W light bulb, and the light bulb must be kept at a fixed height above the photovoltaic cell, to ensure a fair test. I will cover the experiment with a cardboard box to ensure that the only incident light comes from the 150W bulb connected to the 230V mains.

Procedure:

Once the above equipment and circuit has been set up, the voltage and current of the circuit can be measured. Vary the resistance of the resistor and record the voltage and current at each resistance. I have taken some preliminary measurements during the investigation stages of the plan. The bulb was at a height of 0.07 m above the photovoltaic cell.

Calculating the power output of the photovoltaic cell:

Power (W) = Current (A) x Voltage (V)

To measure the power output, plot a graph of voltage against 1/current and measure the gradient of the best fit line.

I used my preliminary results to draw a graph and to measure the power output.

Equation of graph:

y = 0.001x - 1.7657

Gradient  =  Power Output         =  0.001W

Calculating the power input of the photovoltaic cell:

To measure the power input, measure ...