Experiment 222: Solar Panel

Experiment 222: Solar PanelJames CowellHistory

First demonstrated by Edmond Becquerel, a French physicist. He studied the solar spectrum,magnetism,electricityandoptics.He discovered the photovoltaic effect, the operating principle behind a solar cell.The Becquerel prize is named after him, and awarded to people who have excelled in the field of solar energy.

Edmond Becquerel Becquerel Prize awarded to Dr Andreas Bett for solar PV concentrator technology

The Photovoltaic EffectWhen a material is exposed to light and a voltage or electric current is produced, this is the photovoltaic effect.Photons incidence on a surface causes electrons in the valence band to absorb energy and jump to the conduction band, becoming free.These non-thermal electron diffuse, and reach a junction where they are accelerated into a different material by a built in potential, and this generates an electromotive force.Hence, some light energy has been converted into electrical energy.The photovoltaic effect differs to the photoelectric effect as the electron passes directly into a different material rather than having to pass through a vacuum, which causes the photoelectric effect to have a much higher energy threshold.

The two materialsP and N type silicon.N (negative) type silicon has spare electrons, and P (positive) type silicon has an electron deficit.When photons strike the n type silicon, the electrons pass to the p type silicon, which is what produces the electricity.

Uses of Solar CellsPowering your homes:With solar cells on roofs, and huge solar arrays more and more electricity is coming from the sun.Solar powered vehicles:Whilst these are seen as a novelty in some respects, the possible use of solar cells in vehicles is a very exciting prospect.International Space Station:In order to power many space crafts, solar cells are used as they can provide energy to a ship for an indefinite amount of time.

Global Warming!Average temperatures could be between 3 and 9K warmer than now by the end of the century.This is caused by the greenhouse effect:

The UKs energy sources

Much of the UKs energy is non-renewable, and contributes to the greenhouse effect and global warming.There are many available technologies which can help reduce the overall output of non-renewable sources by replacing them with renewables, such as solar power.If this is not prioritised then there could be a climate crisis in the future.

African Solar Energy the Solution?Under a new scheme, 2.5million homes could be powered by Tunisian sunshine by 2018.Up to 2 gigawatts of solar energy could be transported to the UK.Across the UK, only about 6% of energy produced is lost in transmission, meaning that whilst more would be lost in importing from Tunisia, it is a possibility.

The ExperimentCalculating efficiency of the solar cell when different wavelengths of light is incident upon it.All the light energy arriving at the solar cell is not converted into electrical energy, so there is an efficiency. It is almost the same as calculating the error in the solar cell.

The CircuitThe MethodResults

CalculationsExplanation